THE HIDDEN STORY BEHIND INDONESIA'S ETHANOL AND SUGARCANE SYSTEM

 

THE HIDDEN STORY BEHIND INDONESIA'S ETHANOL AND SUGARCANE SYSTEM

                                               Author : AM Tris Hardyanto

1.  The system was never designed for bioethanol; it was designed for sugar.

What if the weakness of Indonesia's bioethanol sector is not technological at all but structural, rooted in a system that was never intended to produce fuel in the first place?

Indonesia's bioethanol production paradigm reflects an agricultural and industrial landscape that has long emphasised sugar above all else. The integration of bioethanol emerged later as an auxiliary function rather than a core strategic objective. Land-use planning, cane varietal selection, irrigation systems, labour organisation, and milling technology were all optimised to maximise sugar yields. As a result, molasses, the essential feedstock for ethanol fermentation, is treated as a secondary commodity whose availability fluctuates depending on sugar production cycles. When sugar supply tightens, molasses is readily diverted to food-grade uses or exported, leaving ethanol production inconsistent and vulnerable (Lukum et al., 2024; Kartika et al., 2024).

 Structural dependency reveals a more profound vulnerability. Ethanol plants operate at the end of the sugar production chain, not as standalone energy assets, leading to volatile, unreliable output levels (Kartika et al., 2024). In practice, bioethanol is produced only when sugar surpluses exist, reinforcing its status as an optional byproduct rather than a strategic renewable fuel. Consequently, the viability of bioethanol as part of Indonesia's national energy security is weakened because its supply hinges on dynamics within an entirely different commodity system (Yuliani et al., 2023).

 dynamic points to a larger hidden issue in Indonesia's renewable energy landscape. Biorefinery models are currently configured to optimise profit within the sugar sector rather than integrate energy and agricultural objectives coherently. The system rewards sugar maximisation, not energy resilience. Yet research consistently shows that sugarcane processing waste, bagasse and filter cake in particular, could be developed as sustainable bioethanol feedstocks, reducing reliance on molasses while also improving environmental performance (Vučurović et al., 2022; Awodi et al., 2022). The potential exists, but the strategic framing does not.

To move forward, Indonesia requires a shift in how bioethanol is positioned within national policy and agricultural economics. Bioethanol must be viewed not as a byproduct of sugar but as a co-equal product with strategic value for energy diversification, economic stability, and climate mitigation (Kaletnіk et al., 2021; Yusof et al., 2019).  This means that aligning feedstock planning, pricing policy, mill operations, and investment incentives is necessary to jointly support sugar production and renewable fuel expansion without competing with food resources.

If Indonesia wishes to build a resilient future in renewable energy, it must redesign the system so that bioethanol is not something that happens only when sugar is abundant but something that is deliberately made possible, planned for, and protected. The real question is not whether Indonesia can produce bioethanol, but whether it is ready to rethink the system that decides what is produced at all.

 

2.  Smallholders bear the burden but do not share in the value.

The most striking irony in Indonesia's sugar economy is that the people who grow the crop shoulder the most significant risks but walk away with the smallest share of the rewards.

In the Indonesian sugarcane sector, smallholder farmers cultivate over 70 percent of the cane, yet they receive only about 20–25 percent of the value generated along the sugar value chain. The imbalance reveals a system that concentrates labour, land, and livelihood at the bottom, while financial benefits accumulate at the top. Smallholders are burdened with rising input costs, especially fertiliser and hired labour, while their income remains dependent on mill-controlled pricing and recovery reporting, processes in which transparency is consistently limited (Suwandari et al., 2025). Payment delays, which can persist for months after cane delivery, further strain farmers' liquidity, directly affecting household stability and seasonal planning (Suwandari et al., 2025).

A more profound inequity lies in how byproducts are treated. Molasses, central to ethanol production, rarely benefits the farmer who cultivates the cane. Mills generally retain the full economic value of molasses and other derivatives, reinforcing a structure where smallholders contribute to system profitability without being recognised as stakeholders in the energy or industrial outputs that follow (Suwandari et al., 2025). Even well-intended initiatives such as the "petani tebu rakyat" scheme, which claims to empower farmers, have not substantially shifted the dynamic. In practice, smallholders subsidise the larger sugar economy through low margins and high-risk exposures (Mjonono et al., 2020).

Restricted access to market information, price signals, and cost-of-production data further reinforces smallholders' limited bargaining power. Without clear visibility, farmers cannot negotiate effectively, plan investments, or evaluate alternatives. Studies indicate that a lack of information leads to diminished asset accumulation, making farmers more vulnerable to market fluctuations and less able to move into value-added or premium market segments (Dlamini et al., 2022). The result is a value chain in which decision-making authority remains concentrated among mills, traders, and policymakers, while the producers who sustain the system are structurally excluded from strategic discussions (Msemwa et al., 2024).

 Intermediaries intensify exclusion by shaping access to credit, input supply, and market connections. Intermediaries often gain leverage when information distribution is uneven, preventing smallholders from securing fair pricing or timely payments (Suwandari et al., 2025). The pattern is clear: smallholders are central to production but peripheral to power and profit. They are essential, yet treated as replaceable. Their role is foundational, yet undervalued.

Behind every sack of sugar and every liter of ethanol lies the labour of farmers who rarely see the value they generate. The issue is not simply economic; it is structural and deeply historical. The real question is how long an industry can remain stable when its foundation is built on those consistently excluded from its rewards.

3.  Molasses is both waste and gold

The story of molasses shows that value is determined by the system that decides what a material becomes.

Molasses, often labelled merely as a byproduct of sugar milling, occupies a paradoxical position in Indonesia's agricultural and energy landscape. On the one hand, it is considered a byproduct of sugar crystallisation. On the other hand, it is an essential feedstock for ethanol production, an ingredient in the animal feed industry, and a high-value export commodity. Dual identity reveals that molasses holds far greater potential than its traditional classification suggests. Recent evidence shows that export prices for molasses frequently exceed domestic prices, prompting mills to direct molasses towards international markets rather than domestic ethanol production (Almunia et al., 2021). The result is a resource that could support renewable fuel security but is instead traded away for short-term revenue.

The absence of regulatory measures requiring domestic allocations reinforces behaviour. Without quota obligations or priority-use policies, mills logically pursue the highest market return, choosing export markets when they offer greater profit margins (Klaver et al., 2023).  creates a structural disadvantage for domestic ethanol producers, who must compete for feedstocks that the national energy system itself does not prioritise. In this sense, the viability of bioethanol is not determined by technology or processing capacity but by market signals that privilege immediate export gains over long-term energy resilience (Almunia et al., 2021).

 Dynamic illustrates a more profound issue: molasses sits at the intersection of agriculture, industry, and national energy strategy, yet its allocation is governed almost entirely by private profitability rather than by public interest. When higher returns abroad outweigh the value of strengthening the domestic energy supply, the nation's renewable energy goals become indirectly undermined. A system that aspires to energy security cannot depend on a feedstock whose distribution is determined by price speculation rather than strategic planning.

Addressing imbalance requires policies that acknowledge molasses as a strategic input rather than an incidental surplus. Introducing domestic allocation quotas, or pricing mechanisms that ensure ethanol producers consistent access to molasses, would stabilise supply chains and reduce volatility in ethanol production. Such measures would also indirectly support farmers, because a stable ethanol sector creates more predictable demand for sugarcane, reinforcing the broader agricultural economy through a circular system in which byproducts fuel new value creation.

Molasses teaches us that what appears to be residue can hold the key to transformation. The question is not whether molasses is valuable, but who gets to decide its value and for what future. If Indonesia recognises molasses as more than just waste, it could become the quiet foundation of a more resilient, self-sustaining energy landscape.

4. Ethanol pricing is formulaic but disconnected from reality.

A pricing system can look rational on paper, yet still fail everyone who depends on it. Indonesia's ethanol pricing framework is one such system.

Ethanol pricing in Indonesia is governed by the Harga Indeks Pasar (HIP), which links the ethanol price to molasses costs plus a fixed margin. In theory, a formula is intended to shield producers from market volatility and ensure predictable returns. However, the practical outcomes reveal a significant disconnect between the formula and the realities of production and trade. Molasses price fluctuations directly influence HIP calculations, yet the timing of refinery purchases and the patterns of offtake often do not align with producer expectations. As a result, the stability promised by the HIP mechanism exists more in policy documents than in daily operations.

When molasses prices rise, the HIP increases accordingly. On paper, it should increase ethanol producers' revenue. In practice, refiners frequently delay purchasing ethanol during these periods in anticipation of price readjustments, reducing the intended benefit of the price increase. Conversely, when the HIP falls, producers lose incentive to maintain or expand production, as narrowing margins undermine profitability. This leads to a cycle of uncertainty on both sides of the market. The pricing formula responds to price movement, but it does not provide the predictability needed for producers to invest in capacity, technology upgrades, or long-term operational planning.

The lack of guaranteed purchase volumes deepens instability. Producers are given a price formula but not a guarantee that their ethanol will be purchased. The result is a system that appears structured, yet leaves producers vulnerable to shifts in feedstock availability, financing pressures, and international commodity price movement. Instead of serving as a stabilising mechanism, HIP often amplifies uncertainty and undermines producer confidence. Markets need not only price frameworks but also predictable access and purchasing commitments to function sustainably.

 The lack of coordinated policies that link molasses allocation to domestic ethanol needs exacerbates the situation. Without dedicated feedstock assurance, the ethanol sector is forced to compete with export-driven molasses markets that often offer higher short-term returns. Establishing domestic allocation measures for molasses would help anchor ethanol production within national energy policy rather than exposing it to speculative global pricing.

The disconnect between the pricing formula and lived realities raises a more profound question: Is Indonesia's ethanol sector being asked to build a stable industry on unstable foundations? Without aligning pricing, supply allocation, and guaranteed market access, ethanol remains a product of chance rather than strategy. The future strength of the industry will depend not on new formulas, but on the willingness to link prices to real conditions and real commitments.

5.  Cassava: the untapped promise with political landmines

A crop can be abundant, adaptable, and scientifically promising, yet remain locked behind political caution. Cassava is one such crop.

Cassava offers an appealing opportunity to diversify Indonesia's ethanol feedstock portfolio, particularly given its widespread cultivation and adaptability to diverse soil conditions. However, its formal designation as a food-security crop complicates its role.  Categorisation positions cassava within national political discourse as a staple that must be protected, creating the perception that using fresh cassava as biofuel directly competes with household food consumption. As a result, any attempt to reallocate cassava from food to energy is treated with political sensitivity, unless the feedstock source is explicitly derived from agricultural waste streams, such as cassava pulp from starch production (Nuwamanya et al., 2011; Zhu et al., 2013).

The politics surrounding cassava are further intensified by the interests of the starch industry, which controls not only fresh root processing but also the flow of byproducts. Cassava pulp, despite being rich in residual starch and lignocellulosic matter, is not easily accessible to external users because its allocation is tightly managed. Yet the same cassava pulp presents a strong technical basis for ethanol production. Studies consistently highlight its capacity to yield fermentable sugars and to achieve efficient ethanol conversion when properly processed (Ezebuiro & Ogugbue, 2015; Archibong et al., 2016). Here, cassava pulp occupies an intriguing space: it supports biofuel development while reinforcing food security by ensuring that ethanol production relies on waste streams rather than edible raw materials.

Realising potential requires more than acknowledging the possibility. It demands coordinated industrial partnerships, investment in processing infrastructure, and technological adaptation tailored to cassava pulp's material characteristics. The technology necessary for effective pulp fermentation is already available, and several studies have demonstrated high ethanol yields under optimal pretreatment and enzymatic hydrolysis conditions (Ndubuisi et al., 2018; Krajang et al., 2021). The challenge, therefore, is not technical feasibility but establishing institutional trust and collaborative frameworks among farmers, processors, technology providers, and government agencies.

Strategically prioritising cassava pulp also offers a balanced pathway to expand renewable fuel production while maintaining adherence to national food policy commitments. By using pulp rather than fresh roots, Indonesia can reduce waste, increase industrial efficiency, and generate a new revenue stream for agricultural producers without disrupting food supply chains. The approach strengthens both energy resilience and farmer livelihoods by creating multiple value nodes within the same crop system.

Cassava's promise does not lie in replacing food with fuel; it lies in recognising value where it has long been overlooked. The real question is whether Indonesia can navigate the political landscape with enough clarity to transform cassava pulp from a byproduct into a cornerstone of sustainable energy strategy.

6.  Farmers face "input inflation" without yield growth.

When costs rise but harvests stay the same, something more profound than price is broken in the system.

Sugarcane farmers in Indonesia are experiencing a sharp increase in production costs, particularly for fertilisers, labour, and irrigation, which have risen by approximately 15–25 percent since 2021. However, yields remain largely stagnant, typically ranging from 55 to 70 tonnes per hectare, and often lower among independent smallholders.  The widening gap between rising inputs and unchanged outputs highlights an underlying structural challenge: farmers are spending more without producing more. Such a pattern signals inefficiencies in both farm management systems and broader agricultural support structures.

Several factors contribute to the stagnation. Many farmers continue to cultivate ageing sugarcane varieties that are no longer well-suited to changing environmental conditions or to emerging processing technologies. These varieties may still grow, but they do not perform at optimal productivity levels. Soil management practices further constrain yields. Maintaining soil fertility requires technical understanding and adaptive management, yet many farmers lack access to the agronomic knowledge needed to replenish soil nutrients effectively. In addition, limited mechanisation results in labour inefficiencies, especially in planting and harvesting. Fragmented irrigation systems complicate water management, causing uneven or insufficient distribution that directly suppresses yield potential.

To move beyond stagnation, changes must occur both at the farm and institutional levels. Improving productivity requires coordinated land management, where consolidation or cooperative land-use arrangements enable economies of scale. Without such arrangements, farmers struggle to adopt mechanisation and modern cultivation techniques that require larger or shared operational units. While government subsidies can temporarily reduce financial pressure, subsidies alone cannot solve systemic inefficiencies. Lasting improvement calls for integrated strategies that support innovation, technology transfer, and shared learning networks among farmers.

Introducing modern agricultural technologies can enhance efficiency, but robust support systems must accompany technology adoption. To make informed decisions, farmers require access to tailored extension services, credit mechanisms that align with productive investment, and reliable market information. Studies consistently show that farms adopting improved technologies achieve better technical and economic performance, yet adoption is slow when farmers are left to absorb the risk alone. Cooperative farming models offer a practical pathway, enabling resource pooling, cost reduction, and shared experimentation with improved practices.

The challenge is not merely that inputs are rising. It is that farmers are fighting alone, with outdated tools and fragmented support. The real breakthrough will come when the system begins to reward knowledge, collaboration, and soil stewardship as much as it currently rewards purchased inputs. Until then, yield growth will remain elusive, no matter how much farmers spend.

7.  Land rent fell, but not because farming got cheaper

When the price of renting land drops, many assume that agriculture has become more efficient. However, in Indonesia's recent case, the opposite is true.

The decrease in land rental prices observed around 2024 to 2025 should not be interpreted as evidence of reduced farming costs or improved agricultural performance. Instead, it reflects deepening financial stress among farmers and landowners. The decline signals that farming is becoming less profitable, forcing landowners to accept lower rental fees to keep their land cultivated. In a healthy agricultural economy, rising productivity and strong market prices would support stable or increasing rent values. Here, lower rents reveal a sector moving under strain rather than advancing through efficiency.

 The trend is intertwined with the declining profitability of key crops. As returns decline, landowners shift from fixed cash rental arrangements toward profit-sharing agreements. These sharecropping-style arrangements allow landowners to cope with uncertain market conditions, yet they also indicate shortages of liquid capital in farming communities. When cash flow is uncertain, landowners hedge risk by tying their income directly to seasonal yields rather than fixed rents. The adjustments reveal a system that prioritises short-term survival over stable income generation.

At the same time, farmers respond to rising production costs for fertiliser, labour, and irrigation by adjusting their cropping strategies. Many turn to shorter-cycle or lower-input crops when margins on traditional cash crops narrow. While these decisions help farmers manage immediate financial pressures, they also disrupt established planting patterns and reduce the land's long-term economic value. A system that encourages farmers to choose crops for survival rather than strategic development will naturally exert downward pressure on land rents, as the land itself becomes less able to sustain profitability.

These changes reflect a broader, often-overlooked reality: lower land rents are not always a sign of efficiency. They can instead mark a retreat from investment, technological adoption, and long-term planning. When farmers operate in a context of persistent uncertainty, they scale back, simplify, and seek flexibility. The cumulative effect is declining land value, not because the cost of farming has improved, but because it has become harder to sustain.

The drop in land rent is not an economic relief; it is a warning. It signals a silent erosion of confidence in the future of agriculture. The question now is whether Indonesia will intervene with policies that rebuild profitability, support knowledge-based farming, and restore land value, or allow the trend to deepen into a cycle of decline where land becomes cheaper because farming itself is no longer viable.

8.  Technology exists, but trust does not

Innovation alone does not change agriculture. People do. Moreover, when trust is missing, even the best technology sits unused.

Although Indonesia has access to a wide range of advanced agricultural technologies, including GPS-based field mapping, mechanical harvesters, and digital soil measurement tools, adoption among farmers remains relatively low—estimated at only 20 to 30 per cent. The challenge is not primarily technical. It is social and economic. Farmers often face high upfront investment costs, uncertain profitability, insufficient training support, and deep scepticism about whether these technologies genuinely serve their interests or mainly benefit larger agribusinesses (Grabowski et al., 2019; Jayashankar et al., 2018).  The environment underscores that trust and perceived fairness shape adoption just as much as efficiency or productivity gains.

The financial barrier is transparent. For many smallholders operating on thin margins and irregular cash flow, the risk of purchasing new machinery or digital tools is daunting. Rising production costs already limit their ability to experiment. If they are not confident that technology will improve yields or reduce labour, they naturally hesitate to invest (Ryan, 2022). Maintenance expenses often deepen hesitation. Modern equipment requires ongoing technical support that rural areas may not be equipped to provide, reinforcing the fear that breakdowns could become liabilities rather than assets (Raturi et al., 2022).

Training gaps further reinforce resistance. Many farmers have limited exposure to structured, hands-on technical learning. Without clear guidance, the promise of technology feels abstract and uncertain. Where knowledge transfer is weak, the perception of risk becomes more substantial than the hope of benefit (Hua-wei et al., 2022).  Dynamic is not merely practical but psychological. If farmers do not feel confident or respected in the learning process, adoption becomes even more unlikely.

Trust shapes all of these decisions. If farmers believe that technology primarily favours larger, wealthier producers, they may conclude that adopting such innovations will only widen inequality (Alexander et al., 2023; Zhou et al., 2023). Trust is not built through instruction manuals or price subsidies. It is built through relationships, shared learning, and credible local examples. When farmers see their neighbours succeed with new practices under conditions similar to their own, technology begins to feel relevant rather than imposed.

Partnership-based approaches offer a pathway forward. Demonstration plots, cooperative equipment ownership models, farmer-to-farmer learning networks, and community-led training programs can reduce perceived risks and show practical outcomes (Ren et al., 2022). These approaches also shift technology adoption from being an individual gamble to a collective progression. When training includes not only how to operate equipment but also how it affects long-term soil health, labour efficiency, and income stability, technology becomes a tool that supports resilience rather than uncertainty (Hua-wei et al., 2022).

The technology needed for more productive and sustainable agriculture is already here. The missing belief is that it belongs to everyone, not just those who are already privileged. The future of Indonesia's farming system will depend not solely on machines and data, but on whether farmers feel included, respected, and supported in the process of change.

9.  Indonesia is caught between two ministries

Even with the right resources, technology, and ambitions, a country can fail if its institutions lack alignment. Indonesia's bioethanol story is a clear example of how misaligned institutions can hinder progress.

Indonesia's bioethanol policy currently operates within a divided governance structure. The Ministry of Energy and Mineral Resources (ESDM) is responsible for shaping renewable fuel targets and determining ethanol blending requirements. Meanwhile, the Ministry of Agriculture (Kementan) regulates the feedstocks that make ethanol possible, including sugarcane, molasses, and cassava. Each ministry holds authority over a critical piece of the value chain, yet they work in parallel rather than in coordination. Their data systems, program objectives, and budget allocations remain largely independent. As a result, the policy environment becomes fragmented, making it impossible to sustain the success of one ministry without corresponding action from the others.

 Separation creates practical inefficiencies. ESDM may advance blending mandates to support renewable energy goals, but if Kementan does not align farm-level production incentives or feedstock supply planning, ethanol producers are left without the raw materials needed to meet the target. Similarly, if energy-market regulations fail to ensure stable demand, increases in agricultural output do not automatically translate into expanded fuel production. Inertia or constraints in one domain repeatedly neutralise progress in the other.

Effective bioethanol development requires policies to be synchronised across the entire chain—from land planning and crop support to milling efficiency, logistics, pricing frameworks, blending mandates, and consumer fuel distribution. Around the world, successful transitions to biofuel economies have relied on horizontal integration among ministries and vertical integration linking national directives to provincial and local implementation systems. Each sector advances its priorities when governance remains siloed, ignoring the dependencies that define shared outcomes.

Creating an integrated bioethanol authority would provide a mechanism to unify these frameworks. Such an institution could harmonise standards, coordinate feedstock allocations, facilitate shared data platforms, align subsidies or investment incentives, and ensure that policy shifts in one domain do not unintentionally destabilise another. With shared planning and accountability, Indonesia could replace fragmented efforts with coherent progress, reducing volatility for farmers, mills, and fuel producers.

Indonesia's challenge is not merely technical. It is institutional. The system must learn to govern energy and agriculture as interdependent elements of the same strategy; otherwise, bioethanol will remain a promising vision that never fully materialises. The question is whether Indonesia can move from two ministries working side by side to one coordinated effort working toward a shared national future.

10.     The public does not see ethanol as an energy issue, only as sugar's cousin

It is possible for a renewable fuel to be both visible and invisible. In Indonesia, ethanol has potential, but not in narrative.

In Indonesia, ethanol is widely perceived as a derivative of the sugar industry rather than as a strategic renewable fuel.  Initiatives like the B35 programme have successfully positioned biodiesel as a national achievement, in stark contrast to the perception of ethanol. Biodiesel is recognised as an energy source. Ethanol, however, remains seen as "sugar's cousin" a secondary output rather than a primary contributor to energy security.  Invisibility limits ethanol's political influence, budget allocation, and relevance in public discussions about energy transition.

Public perception matters because visibility drives funding and policy priorities. Biodiesel has benefited from strong government messaging, industry alignment, and a narrative that connects it to national pride and economic independence. Ethanol never received the same narrative infrastructure. Its identity is tied to sugarcane mills, molasses markets, and agricultural pricing disputes rather than clean energy targets or national decarbonisation efforts. As a result, ethanol struggles to gain the political capital necessary to advance beyond pilot-scale and intermittent production.

 The institutional divide between the Ministry of Energy and the Ministry of Agriculture further reinforces perception. The Ministry of Energy focuses on blending mandates and energy diversification, while the Ministry of Agriculture manages feedstock policies and farmer livelihoods. When ethanol is framed as an agricultural commodity rather than a fuel, its development remains overshadowed by the more visible biodiesel sector, which benefits from palm oil's strong domestic industry and lobbying power. Without linked goals, aligned data systems, and coordinated investment strategies, ethanol remains trapped in a supporting role.

The lack of a unified public narrative also undermines investment confidence. When the public does not recognise ethanol as part of the nation's energy future, the private sector sees a signal of uncertainty. Research, infrastructure expansion, and conversion technologies require long-term stability, but stability cannot form without shared belief in ethanol's strategic relevance. Public trust, corporate commitment, and policy momentum are intertwined.

Ethanol's greatest challenge is not chemistry or technology, but identity. Until Indonesia chooses to tell a story in which ethanol is energy, not sugar's byproduct, the fuel will remain underused and undervalued. The future of ethanol depends not only on what the country can produce but also on what it chooses to believe about it.

11.     Academia and research are advanced but disconnected from policy rollout

Innovation does not pose a challenge. Indonesia has the science, the laboratories, and the prototypes. What is missing is the bridge that carries ideas from research rooms into real fields and factories.

Indonesia's bioethanol sector reveals a striking gap between sophisticated academic research and its practical implementation in agricultural and industrial systems. Institutions such as BPPT, LIPI, and P3GI have developed technologies ranging from hydrolysis enzymes to improved distillation systems and vinasse treatment methods. However, these breakthroughs rarely progress beyond pilot facilities. Many pilot plants serve as isolated demonstrations rather than as starting points for industrial expansion, mainly because funding cycles are short and inconsistent, unable to sustain the long-term processes required to translate laboratory success into scalable production (Rivai, 2022; Sajida, 2022).

The core issue is not innovation capacity but the absence of institutional continuity. Research programs frequently begin with promising momentum only to lose support before they mature into commercially viable applications. Lack of longevity in funding structures leads to institutional memory fading and a failure to transfer lessons learnt into ongoing industrial or policy planning.  creates a cycle where Indonesia repeatedly rediscovers solutions it has already invented, rather than implementing and scaling them (Kusumawardani et al., 2021; Haryatie et al., 2023).

Policy fragmentation exacerbates these challenges. Research that could inform feedstock strategies, refinery upgrading, or energy diversification remains siloed because agricultural and energy authorities operate under separate mandates. Without a common platform that forces shared planning, promising innovations remain disconnected from real market ecosystems. As a result, research outcomes do not meaningfully influence the design of industrial policy, investment priorities, or procurement standards (Nurhasan et al., 2021; Ardiansyah et al., 2024).

 Disconnect is not inevitable. Countries that have successfully integrated biofuel research with industrial rollout such as Brazil have done so through stable funding systems, cross-ministerial coordination, and strong public-private partnerships. Indonesia could adopt similar approaches. Long-term funding frameworks, multi-stakeholder research consortia, and shared evaluation metrics would strengthen continuity. If research institutions built structured partnerships with mills, smallholders, and technology developers, bioethanol innovation could shift from isolated prototypes to interconnected value chains (Sajida, 2022; Miryanti et al., 2023).

Indonesia's research capacity is not a barrier. The science is in place. The question is whether the country will create a system that allows knowledge to move steadily, deliberately from laboratories into landscapes. Indonesia's ability to sustain, coordinate, and scale bioethanol production will determine its future.

 

12.     The ethanol dream keeps being recycled every decade

Every ten years, a nation repeats the same dream, recycling not only ambition but also the same unresolved problems.

Indonesia's bioethanol development history reveals a recurring cycle of enthusiasm, policy launches, and eventual stagnation. The 2006 Biofuel Presidential Decree, the 2010 E3/E5 pilot programme, the 2015 Bioenergy Grand Strategy, and the 2023 E5 Relaunch each emerged with optimism and national rhetoric about energy independence. However, each initiative encountered the same structural constraints: uncertain feedstock availability, volatile pricing, and fragmented coordination between agriculture and energy institutions. The pattern suggests not a failure of technological innovation, but a deeper institutional inertia that continues to limit the sector's progress.

Despite advances in bioethanol conversion efficiency, such as improvements in hydrolysis enzymes, fermentation optimisations, and distillation technologies, these innovations have not translated into stable industrial production (Kusumawardhani et al., 2022). Instead, each new policy cycle introduces revised slogans and technical strategies without confronting the systemic issues that have persisted across decades. The result is a repeated relaunching of bioethanol as if it were a new idea, rather than an unfulfilled one.

Feedstock dependence is at the centre of repeated stagnation. Reliance on sugarcane and molasses ties ethanol output to agricultural fluctuation, price competition, and mill-level priorities, which are themselves unstable (Agustian et al., 2021). When sugar supply tightens, molasses disappears from domestic ethanol channels. When prices rise, mills prioritise their exports. These recurring bottlenecks re-emerge with each policy cycle, stalling momentum just as progress begins to form.

Institutional misalignment compounds the issue. Energy policies are formulated independently from agricultural policies, and the absence of a cross-sector authority allows each ministry to pursue its own logic. Without integrated governance, the capabilities of one sector routinely fail to support the goals of the other (Kusumawardhani et al., 2022). On paper, efforts may progress, yet they stagnate in practice due to the implementation system's lack of structural design for coordination.

Public perception further shapes the cycle. Biodiesel has secured national narrative visibility through campaigns like B35, whereas ethanol remains obscure in public discourse. With low recognition comes low political investment. Without political investment, funding remains limited. Moreover, without sustained funding, programmes fade from view—until they are revived again a decade later (Tjahjono et al., 2021). The cycle repeats because no single cycle builds lasting institutional memory.

Indonesia does not lack the science, the policy blueprints, or the ambition to scale bioethanol. What it lacks is continuity, coordination, and narrative ownership. The next generation of ethanol will not succeed by launching yet another program. It will succeed only when the country decides to stop returning to the same starting point and instead builds a system capable of carrying momentum forward. The real question is whether Indonesia is ready to break the cycle or repeat it once more in the next decade.

 

Rich Land, Unreached Hands

The story of ethanol in Indonesia is not simply a matter of production capacity or technological readiness. It is a window into deeper structural patterns that shape how agriculture, industry, and energy policy interact or fail to interact.

The challenges faced by ethanol producers are not rooted in a lack of appropriate technology. Boilers, fermentation agents, and distillation systems are widely understood and available. The difficulty lies in the ecosystem surrounding them. Farmers, mill operators, and policymakers each operate within different incentive structures, time horizons, and risk perceptions. These differences create misalignment, making it challenging to coordinate a stable, long-term bioethanol strategy.

Indonesia's history with ethanol reflects a pattern of misalignment. National initiatives have appeared repeatedly, roughly once every decade: the 2006 Biofuel Presidential Decree, the 2010 E3/E5 Bioethanol Pilot Program, the 2015 Bioenergy Grand Strategy, and most recently, the 2023 E5 Relaunch. Each policy cycle began with optimism but ended with familiar obstacles. Feedstock uncertainties, volatile pricing, and fragmented governance prevented sustained implementation.  Repetition reveals a deeper issue: the barriers are structural, not technical. Policies shifted, but the system surrounding ethanol did not.

Smallholder farmers illustrate tension clearly. Many operate with thin margins and limited cash flow, prioritising short-term survival over long-term investment in feedstock systems aligned with energy goals. Meanwhile, mills respond to global and domestic price signals rather than national energy narratives. Policymakers, working within ministry-specific mandates, set targets that do not always correspond to conditions on the ground. These differing realities create a persistent gap between strategy and practice.

Moving forward requires reframing sugarcane agriculture, molasses allocation, and renewable energy planning as interdependent rather than separate domains. A cohesive approach would align incentives across the value chain, promoting cooperation rather than competition. Establishing a cross-ministerial bioethanol authority could help harmonise policies, coordinate budgets, and standardise data sharing. Strengthening communication channels between farmers and mills would also help ensure that shared goals rather than isolated interests guide feedstock decisions.

The future of Indonesia's ethanol sector will depend on tackling structural fragmentation as seriously as technical optimisation. Sustainable progress requires long-term policy continuity, integrated governance, stable market commitments, and shared incentives that link agricultural livelihoods with energy security.

 

Indonesia has never lacked the vision to pursue bioethanol. What it has lacked is a system capable of carrying that vision forward. If the country can finally integrate the pieces of the ecosystem farmers, feedstocks, mills, and ministries then the ethanol dream will no longer need to be recycled every decade. It can, instead, become reality.

 

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4.      Diagnostics of the efficiency and assessment of the possibilities of bioethanol production at sugar beet industry enterprises and distilleries in Ukraine 10.33223/epj/135586 Grygorii Kaletnik, Natalia Pryshliak, Yana Palamarenko Polityka Energetyczna – Energy Policy Journal Polityka Energetyczna – Energy Policy Journal Instytut Gospodarki Surowcami Mineralnymi i Energia Polskiej Akademii Nauk 137-156

5.      Economic comparison of decentralized <scp>versus</scp> centralized processing of sugarcane to fructooligosaccharides and ethanol 10.1002/bbb.2525 Monique Klaver, Abdul M. Petersen, Johann F. Görgens Biofuels Bioproducts and Biorefining Biofuels Bioprod Bioref Wiley 1566-1578

6.      Exploring sago potential in Meranti Islands Regency: A comprehensive analysis for sustainable bioethanol production in Indonesia 10.1088/1755-1315/1359/1/012066 Nurullaily Kartika, Nastiti Siswi Indrasti, Lina Karlinasari, Agus Eko Tjahjono Iop Conference Series Earth and Environmental Science IOP Conf. Ser.: Earth Environ. Sci. IOP Publishing 12066

7.      Influence of Sunflower Value Chain Production Activities on the Smallholder Farmers' Livelihood in Tanzania: A Case of Mpwapwa District 10.51505/ijebmr.2024.8214 Lukas Simon Msemwa, Jacqueline Christopher Macha, Diana Daniel Kiwia International Journal of Economics, Business and Management Research IJEBMR International Journal of Medical Science and Health Research 170-186

8.      Life Cycle Assessment for Bioethanol Production from Oil Palm Frond Juice in an Oil Palm-Based Biorefinery 10.3390/su11246928 Siti Jamilah Hanim Mohd Yusof, Ahmad Muhaimin Roslan, Khairul Nadiah Ibrahim, Sharifah Soplah Syed Abdullah, Mohd Rafein Zakaria, Mohd Ali Hassan, Yoshihito Shirai, Sustainability, Sustainability MDPI AG 6928

9.      Production of bioethanol from molasses by varying brix and yeast concentration 10.1088/1755-1315/1425/1/012026 Astin Lukum, Aura Dwi Kurnianda Tangahu, Erni Mohamad, Kostiawan Sukamto, Arfiani Rizki Paramata Iop Conference Series Earth and Environmental Science IOP Conf. Ser.: Earth Environ. Sci. IOP Publishing 12026

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12.  Value for smallholder farmers participating in the agricultural value chain: towards the development of a conceptual framework 10.17306/j.jard.2020.01209 Mfusi Mjonono, Nyankomo Marwa, and Gerhard Coetzee authored the article published in the Journal of Agribusiness and Rural Development (J. Agribus.). Rural Dev. Uniwersytet Przyrodniczy w Poznaniu (Poznan University of Life Sciences) 37-44

13.  Venting Out: Exports during a Domestic Slump 10.1257/aer.20181853 Miguel Almunia, Pol Antràs, David López Rodríguez, Eduardo Morales American Economic Review American Economic Review American Economic Association 3611-3662

 

 

The Wall That Holds Back the Future: Indonesia's Great Java Seawall and the Moral Geometry of Climate Engineering

 

Author : AM Tris Hardyanto

The Wall That Holds Back the Future: Indonesia's Great Java Seawall and the Moral Geometry of Climate Engineering

 

1         The Wall That Thinks It Can Hold the Ocean

Every civilisation has drawn a line against nature. For the Romans, it was a Railway. For Daendels, it was the Great Post Railway, a thousand-kilometre scar of control across Java's body. Today, Indonesia draws another line, not through the jungle but along the sea with a colossal wall that claims to protect 140 million people from the tides.

However, beneath every block of concrete lies a deeper question: can engineering ever command the living sea without becoming part of it?

The Great Java Seawall is not just a feat of civil engineering; it is a moral experiment. It tests how far human ambition can stretch before wisdom must take the lead. It forces us to ask whether progress is measured by how high we build or how humbly we learn to bend.

As history unfolds, imagine Daendels' Railway meeting the waves, the empire's geometry colliding with the climate's uncertainty. Between the two lies the story of a nation still learning how to build, not over the land, but with the ocean itself.

 

1.1     Echoes of Empire: From Daendels' Railway to Prabowo's Climate Walls

In 1808, Governor-General Herman Willem Daendels stood on the storm-bitten beach of Anyer and pointed east. Within three years, a line of Railway would stretch more than a thousand kilometres to Panarukan, a scar of empire carved through jungle, floodplain, and suffering. The Great Post Railway was intended to unify Java, the heart of the Dutch East Indies, under a single, disciplined spine. Two centuries later, Indonesia draws another line across the same island, not to command its people, but to defy the ocean itself.

The North Java Seawall, now unfurling from Banten to Gresik, promises protection for over 140 million citizens and half the nation's economy. However, beneath the concrete slabs and tide gates lies a question as profound as Daendels' Railway once posed: how far can engineering stretch before it becomes destiny?

Like its predecessor, the Seawall is both a triumph and a warning. It represents the will of a rising nation to stand firm against climate peril but also exposes the limits of human ingenuity in the face of living coastlines. For every kilometre of wall that rises, a mangrove forest gasps for space; for every drained neighborhood saved, another quietly sinks under its own thirst for groundwater.

The Semarang–Demak section, a 6.7-kilometre fortress that doubles as a toll road, is a microcosm of modern paradox. Commuters celebrate smoother journeys, while fishermen curse shrinking catches. Engineers admire its dual-use design; ecologists note how its embankments cut through sediment flows older than the republic itself. Jakarta, Pekalongan, and Cirebon await their turn, each promising to learn from the last, yet all caught in the same equation of urgency versus uncertainty.

Indonesia's planners call it a "hybrid defence", a mix of sea dikes, mangroves, and strategic retreat. The rhetoric is noble; the execution, delicate. To build a wall is simple. To build a wall that breathes, listens, and evolves with the sea requires an entirely different ethos, one that blends hydraulics with humility.

For civil engineers worldwide, Java's experiment is not a local story. This experiment serves as a preparation for the century to come, when nations ranging from Bangladesh to California will establish their own defensive boundaries. The challenge is no longer how to resist nature but how to reconcile with it to design for movement, not conquest.

Daendels built a Railway to connect a colony. Prabowo’s generation builds a wall to protect a democracy. However, the same moral geometry endures: straight lines promise control, but life moves in curves. The height of its concrete will not measure the success of the Great Java Seawall, but the depth of its wisdom will.

 

1.2        Engineering the Future: Hybrid Defenses and the Ethics of Adaptation

Indonesia’s Great Java Seawall stands at the centre of a national climate-adaptation initiative along the island’s northern coast, where rising seas and accelerating land subsidence have redrawn the boundaries between land and ocean. Scholars such as Triana and Wahyudi (2020) identify these twin forces as the primary drivers of coastal vulnerability across the archipelago, intensifying threats to infrastructure, settlements, and livelihoods. In this setting, the Seawall serves not only as a hydraulic structure but also as a social statement, translating uncertain hydrology into a visible, engineered order. The challenge lies in recognising that climate adaptation is never purely a technical matter. Every metre of wall expresses a normative judgement about who bears risk, who benefits from protection, and how society chooses to live with environmental uncertainty. The question, then, is whether the wall can evolve beyond a rigid defence line into a dynamic system that works with the sea rather than against it.

Indonesia’s resilience agenda increasingly recognises this complexity. Policy discussions now describe the Seawall as part of a hybrid defence system, an integrated design that couples engineered barriers with nature-based measures and flexible retreat strategies (Prayoga, 2025). In this configuration, dykes, mangroves, and planning instruments work together to reduce flood exposure while preserving ecological processes. The concept of hybridity reframes resilience as something achieved not through total fortification but through the interplay of complex infrastructure, living buffers, and adaptive governance. This hybrid vision transforms the Seawall from a single monument of protection into a co-constructed landscape where technology, ecology, and equity converge.

At the micro scale, this hybrid defence becomes tangible in the meeting points of embankments, access roads, and tidal flows. Infrastructure modifies sediment transport and water circulation, producing both intended protection and unintended disruption to coastal ecosystems. Such interventions protect transport routes and residential areas but can alter fisheries and mangrove habitats that sustain local livelihoods. These tensions highlight the dual nature of climate engineering: benefits accrue to some groups and scales, while others face new ecological or economic costs. The ability of adaptation policy to align technical outcomes with community needs thus becomes a key test of governance capacity and justice.

The Semarang–Demak section, a 6.7-kilometre seawall that doubles as a toll road, illustrates these contradictions vividly. For commuters and urban planners, it symbolises progress and connectivity; for nearby fishers, it signals restricted access and ecological disturbance. Torabi and Dedekorkut-Howes (2020) argue that managed retreat, relocation, and ecosystem restoration should be considered alongside physical defences within an integrated coastal engineering portfolio. Viewed through this lens, the Semarang–Demak wall is not merely an isolated barrier but a microcosm of the national challenge: balancing economic development with ecological continuity and community resilience.

Ethical reflection deepens this technical debate. Liss et al. (2025) emphasise that adaptation measures must incorporate climate justice to avoid reproducing inequality. The social legitimacy of large-scale defences depends on transparent, participatory governance that ensures equitable risk sharing. In Indonesia, this means that the success of the Great Java Seawall cannot be measured solely by its hydraulic performance. Its moral legitimacy derives from how well decision-making includes marginalised voices and distributes the benefits and burdens of protection fairly. The Seawall, therefore, becomes both a structure of concrete and a test of governance ethics.

 

1.3        Beyond the Wall: Coexistence, Justice, and the Wisdom of Resilience

From a global perspective, Java’s Seawall echoes ongoing debates about climate engineering and distributive justice. Large-scale interventions often privilege metropolitan and industrial zones, raising the same dilemmas faced in international climate governance: who decides, who benefits, and who is left at risk? Skidmore and Cohon’s multicriteria decision analysis (MCDA) framework, applied to coastal adaptation, provides a transparent pathway for navigating such choices by weighing ecological, social, and economic criteria (Nurul et al., 2025). Applying this method to Indonesia could help policymakers balance competing objectives and clarify the trade-offs inherent in “holding the line” versus retreating strategically.

The historical resonance of the project amplifies its moral undertones. The Seawall recalls Daendels’ early nineteenth-century Anyer–Panarukan Railway, a straight line carved across Java to assert colonial order over a restless landscape. Both the infrastructure railway and wall represent state ambitions to impose geometric certainty on dynamic environments. However, as Torabi and Dedekorkut-Howes (2020) remind us, resilience depends on accepting that natural systems exhibit cyclical patterns. The moral geometry of modern climate engineering must therefore shift from domination toward coexistence, designing defences that adapt to nature rather than attempting to freeze it in place.

A holistic framework for climate adaptation reinforces this ethical and ecological synthesis. Mycoo (2013) and other coastal researchers advocate for integrated approaches that combine technical, social, and environmental dimensions through adaptive management. In the case of the Java Seawall, this means viewing resilience as an ongoing negotiation rather than a finished structure. The success of adaptation depends as much on inclusive governance and community learning as on engineering precision. Mangrove restoration, sediment management, and participatory planning, when combined, can transform the wall from a symbol of separation into a bridge between human and natural systems.

In conclusion, the Great Java Seawall embodies both ambition and reflection, a line that holds back the sea while inviting society to reconsider what it means to live with water. The future of Indonesia’s coasts will not be determined solely by concrete height or hydrodynamic efficiency, but by the wisdom embedded in governance, the humility of its engineering philosophy, and the partnerships forged among state, science, and citizens. If designed and governed with care, the Seawall can become not the wall that divides humanity from nature, but the line that teaches how to share resilience with the sea.

2          Hidden Equations: The Three Forces Behind the Wall

Every significant piece of infrastructure hides an equation deeper than its blueprint, one that balances not only cost and benefit but also justice and ecological truth. Beneath the Great North Java Seawall lie three interlocking forces that define its endurance: the sinking land, the rising sea, and the uneven shore. These forces do not merely sculpt the coast; they shape the moral and technical calculus of those who attempt to defend it.

Key Emerging Risks and Hidden Issues

Category	Description	Implication
Subsidence vs. Sea Defense	Flooding is primarily caused by groundwater over‑extraction, not just sea‑level rise. Seawalls may trap water behind them if pumping and piped water solutions are inadequate.	Long-term ineffectiveness; trapped floodwater and higher O&M costs.
Livelihood Impacts	Fishers and pond farmers near Demak report blocked brackish‑water flow, reduced catches, and salinity imbalance.	Loss of income, social friction, and food‑security concerns.
Ecosystem Fragmentation	Complex structures disrupt mangrove belts and estuarine flows; satellite data show rising land-surface temperatures and habitat loss.	Decline in biodiversity and natural coastal resilience.
Financing Exposure	An estimated US$80 billion project cost over 20 years; risk of fiscal lock-in and foreign debt dependency.	Budgetary stress, especially if economic returns are low.
Governance & Equity	Priority areas (Jakarta, Semarang) receive complete protection; peripheral communities face managed retreat.	Social inequity, land disputes, and resettlement pressure.
Technical Design	A‑uniform coastline requires varied engineering. A rigid “Great Wall” model is unsuitable.	Site-specific adaptation is essential; poor design could cause coastal erosion displacement.

 

 

2.1        Legacy and the Impetus for a Hybrid Approach

The Great Java Seawall inherits a long tradition of adaptive coastal defence. Along Java’s northern littoral, protection has historically combined ecological capacity with engineered form rather than relying solely on complex barriers. This lineage now reappears in Indonesia’s hybrid defence policy, a design philosophy that integrates dykes, mangroves, and adaptive retreat to balance security with ecological integrity (Prayoga, 2025). The hybrid approach signals continuity between past wisdom and modern innovation: protection is not only a technical artefact but also an ecological negotiation that treats living systems as coequal partners in defence. The Seawall thus becomes a visible synthesis of Indonesia’s climate-resilience ethos, an infrastructure designed to work with nature’s flexibility, not against it (Prayoga, 2025).

2.2        The Sinking Land

The ocean is not simply drowning Java’s north coast; it is collapsing from within. In cities such as Semarang and Jakarta, decades of groundwater extraction have led to land subsidence, reaching up to 20 centimetres per year, which outpaces the rate of sea-level rise (Triana & Wahyudi, 2020). The ground sinks under its own weight as aquifers deplete faster than rainfall can replenish them. Engineers can design dykes and pumps, but they cannot design new ground. The result is a paradox: every centimetre the land sinks reduces the effective height of the Seawall, eroding its protection from below. Without firm groundwater regulation and reliable piped-water infrastructure, the wall may transform coastal cities into perpetual pumping basins, a bathtub maintained by machines rather than hydrology (Triana & Wahyudi, 2020). What begins as protection could evolve into technological dependence, where urban survival relies on mechanical effort rather than sustainable resource management.

2.3        The Rising Sea

While human behaviour drives the ground downward, climate physics lifts the sea upward. The Java Sea has risen approximately 12 centimetres over the past half-century, propelled by thermal expansion, melting polar ice, and shifting regional currents (Triana & Wahyudi, 2020). Each centimetre redefines flood probability and redraws the baseline for coastal design. A seawall can buy time, but time itself is a deceptive construction material: concrete decays while pressure persists. Global precedents, from the Netherlands’ Delta Works to New Orleans’ levees, show that coastal defence is never a one-time project but a generational contract that demands renewal and vigilance. As subsidence and sea-level rise intersect, the Java Seawall must evolve dynamically; otherwise, it risks defending yesterday’s shoreline against tomorrow’s tide (Triana & Wahyudi, 2020).

2.4        The Uneven Shore

Beyond geology and hydrology, social inequality forms the third and most elusive force behind the wall. Protection is rarely distributed evenly. Wealthier districts, industrial estates, and toll-road corridors often receive stronger defences, while fishing villages and informal settlements remain exposed or displaced. Climate-justice scholarship emphasises that adaptation decisions—whether to reinforce, retreat, or rebuild—must integrate fairness into governance to prevent amplifying existing inequities (Liss et al., 2025). In Jakarta’s Kampung Akuarium, relocation once erased community memory; in Demak, fish-pond farmers lament sluice gates that choke their brackish livelihoods. A wall that secures profit while marginalising the poor becomes not infrastructure but a weaponised geography. True resilience requires that the calculus of protection include those who cannot pay for it, ensuring that adaptation strengthens rather than fractures social cohesion (Liss et al., 2025).

2.5         The Triple Equation and Ethical Constraints

Subsidence, sea-level rise, and social inequality form a complex interplay that no single hydraulic model can address alone. The challenge extends beyond engineering into ethics and governance. Effective adaptation depends on combining nature-based solutions, institutional reform, and participatory management, ensuring that ecological, technical, and social dimensions operate in concert (Mycoo, 2013). The Java Seawall’s future hinges not only on its concrete height but also on the legitimacy of the decisions that sustain it. Transparent planning, equitable risk sharing, and community participation transform engineering into a form of stewardship. When citizens help monitor groundwater use, replant mangroves, or participate in flood mapping, resilience becomes a shared practice rather than a state-imposed defence (Mycoo, 2013).

2.6         History, Geometry, and the Policy Horizon

This struggle between straight lines and moving coastlines has deep historical roots. In the early 19th century, Governor Daendels carved the Anyer–Panarukan Road across Java, a linear assertion of control over a shifting landscape (Harahap et al., 2024; Zamani, 2022). The modern seawall mirrors that same impulse: to impose order on fluidity. However, nature’s geometry is never linear. Contemporary scholars warn that sustainable defence requires reimagining not only physical barriers but also the social contracts that define how communities live with water (Torabi & Dedekorkut-Howes, 2020). Maintaining a boundary involves both moral and technical considerations, requiring the humility to allow curves to take the place of straight lines and negotiation to replace dominance. The Seawall’s true legacy will depend on whether Indonesia learns to adapt to the coast rather than to bind it.

2.7         Policy Implications and the Path Forward

Current Indonesian policy debates reveal this evolution of mindset. As the nation develops its coastal defence strategy under hybrid and anti-access/area-denial (A2/AD) doctrines, attention has shifted from mere construction to governance, coordination, and social accountability (Prastyo, 2024). Sustainable defence now means aligning national security, climate adaptation, and community participation into a coherent institutional framework. The Great Java Seawall thus becomes a test of moral and administrative maturity: can engineering remain accountable to those it is meant to protect? If Indonesia can reconcile infrastructure with ethics, integrating equity, ecology, and endurance, its Seawall may mark not a wall against the future but a foundation for shared resilience (Prastyo, 2024). The next stage of this inquiry, therefore, turns to how these moral and hydrological variables can be translated into decision-support tools that balance risk, cost, and justice in the century ahead.

 

3          The Living Frontier: Designing Walls That Breathe

Civil engineering has long struggled with a paradox of permanence: we build to endure, yet the environments we inhabit are constantly evolving. The North Java Seawall magnifies that paradox more than any bridge, dam, or highway before it. Its success will depend on whether it can evolve from a defensive monument into what modern engineers call a living system, a synthesis of structure, soil, and society. This transformation necessitates a shift from the rigid geometries of control to a flexible geometry of coexistence. The Seawall must not only resist the sea but also learn from it, integrating ecological intelligence, technological adaptability, and institutional responsiveness as core design principles (Prayoga, 2025; Liss et al., 2025).

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3.1        From Concrete Certainty to Adaptive Design

As discussed in the previous section, Java’s northern coastline is shaped by the interplay of subsidence, sea-level rise, and inequality, which defy static solutions (Triana & Wahyudi, 2020). In this volatile context, the North Java Seawall is being reimagined as a dynamic infrastructure that can respond to change rather than resist it. Traditional coastal design, governed by Newtonian determinism, assumes predictable baselines: engineers calculate hydraulic pressures, apply safety factors, and design for the “100-year storm”. However, when climate baselines shift faster than design codes can be revised, deterministic methods yield false precision (Triana & Wahyudi, 2020).

To overcome this, Indonesian coastal engineers have begun embracing modular and adaptive design philosophies. Modular caisson segments, adjustable floodgates, and built-in settlement joints enable the Seawall to flex with the passage of time and the rise and fall of the tide. In Semarang–Demak, geotechnical teams are experimenting with lightweight fill materials and geotextile-reinforced berms to mitigate land subsidence without sacrificing stability (Prayoga, 2025). These innovations are more than technical responses; they signal a philosophical shift from designing against uncertainty to designing within it. By treating flexibility as a structural strength rather than a flaw, engineers align with a new resilience paradigm where the wall adapts, learns, and evolves in response to its environment.

 

3.2        Engineering with Ecology

The second frontier lies in the relationship between engineering and ecology. The traditional paradigm of conquest, which involves flattening mangroves, straightening rivers, and silencing sediment, has yielded catastrophic results for both ecosystems and the longevity of infrastructure. The eco-hydraulic engineering movement reframes this relationship, urging engineers to treat natural systems not as obstacles but as co-authors of protection (Prayoga, 2025). This approach integrates nature-based solutions into structural systems, transforming rigid revetments into bio-shorelines where concrete transitions into living roots and sediments.

Empirical studies indicate that mangrove forests can dissipate up to 70% of incoming wave energy before it reaches a wall, while simultaneously trapping sediments that contribute to the rebuilding of coastal land (Prayoga, 2025). In Demak’s pilot restoration zones, engineers have tested combinations of grey-green interfaces, including mangroves, geotextiles, and terraced revetments, that work in tandem. However, ecological engineering requires humility: mangroves cannot be treated as aesthetic decorations or carbon offsets. They need space to fail and recover. Without ecological buffers, rigid walls redirect erosion to neighbouring bays, a phenomenon increasingly referred to as “hydraulic injustice”. Thus, sustainable design must incorporate sediment connectivity, habitat restoration, and adaptive monitoring to prevent protection in one district from causing disaster in another (Liss et al., 2025).

This partnership between civil and environmental engineering transforms the act of building from domination into choreography. The sea ceases to be an enemy and becomes an unpredictable collaborator, requiring a design that breathes with the tides rather than fights them.

3.3        Integrated Drainage and Urban Hydrology

Beyond the Seawall lies another frontier of urban hydrology. Without integrated drainage, coastal defence becomes an inland trap. As cities seal their coasts, rainwater and wastewater accumulate in low-lying basins, demanding continuous pumping to prevent catastrophic backflow (Prayoga, 2025). The master plan for the Semarang–Demak corridor, therefore, integrates the Seawall with inland drainage infrastructure, including retention basins, infiltration corridors, pumping stations, and artificial wetlands, designed to manage water holistically.

These systems convert industrial or underutilised land into multi-functional flood storage zones, doubling as urban green spaces during dry seasons and as reservoirs during monsoons. Intelligent sensor networks, supported by SCADA-based (Supervisory Control and Data Acquisition) systems, synchronise pump operation with tidal cycles, enabling real-time flood management rather than reactive responses. This digital hydrology represents a paradigm shift: engineers no longer design for rare “100-year events” but for continuous feedback loops that update with every storm and tide. In doing so, the Seawall ceases to be an isolated coastal barrier and becomes a central node in a resilient urban water system that learns and adapts (Prayoga, 2025).

 

3.4         Governance as Engineering

No wall can live without institutions that sustain it. Engineering, at its most mature, becomes governance in material form. The longevity of the North Java Seawall depends on institutions that maintain, monitor, and adapt policy in response to evolving data (Liss et al., 2025). Governance, in this sense, is not the paperwork that follows construction; it is the architecture of responsibility itself.

A living wall requires maintenance corridors, budgetary transparency, and accountability chains as vital as its geotechnical foundation. The weakest point in any coastal system is usually not a crack in concrete; it is a gap in coordination. Adaptive governance ensures that when conditions change, whether through subsidence, population growth, or policy reform, the wall’s management evolves with them. Engineers, ecologists, and communities must therefore form a feedback ecosystem that treats monitoring and maintenance as shared civic duties rather than bureaucratic burdens (Liss et al., 2025).

Indonesia’s planners now stand at a historic threshold. The Great Post Railway (Anyer–Panarukan) once symbolised the colonial state’s power to command the landscape (Harahap et al., 2024; Zamani, 2022). The Great Seawall could embody the opposite: a collective capacity to cooperate with it. If the Post Railway was a monument to control, the Seawall could become a monument to collaboration—a structure that protects without dominance and engineers without erasure. The next generation of engineers will calculate not only loads and moments but also coexistence and continuity across decades of climate uncertainty.

 

3.5        The Adaptive Covenant: Toward a Living Infrastructure Ethic

Taken together, these four dimensions—adaptive design, ecological integration, hydrological connectivity, and institutional governance—redefine the North Java Seawall as a living experiment in climate responsibility. It exemplifies a shift from concrete certainty to adaptive stewardship, where engineering becomes a moral and ecological dialogue with the future.

The Seawall’s evolution reflects a broader philosophical awakening: resilience is not merely structural endurance but the capacity of human and natural systems to learn, regenerate, and share risk equitably (Liss et al., 2025). This transformation demands continuous co-production among engineers, communities, and policymakers, turning adaptation into a loop of learning rather than a static line of defence.

Ultimately, the measure of success will not be the Seawall’s height or its lifespan but its humility, its ability to protect while allowing nature to breathe and society to evolve. In this century of rising seas and shifting ethics, the most visionary walls will be those that remember they are temporary guests in a living world.

4         The Moral Geometry: Who the Wall Serves, and Who It Silences

Every Seawall is a mirror. It reflects what a nation fears most and what it values most.
For Indonesia, a nation of 17,000 islands, the fear is not only of being drowned beneath the rising sea but also of being forgotten by the land itself. Villages such as Bedono, Timbulsloko, and Muara Baru have already vanished beneath the tide, remembered only by the tips of mosque domes and fading coordinates on maps. The Great Java Seawall, therefore, stands not merely as a civil works project but as a cultural defence line drawn between survival and surrender.
If the previous section examined how walls might breathe through adaptive design, this section asks: for whom do they breathe, and at what cost?

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4.1        The Cultural Weight of Water

A seawall that purports to safeguard a country's future must first address its historical legacy.
In Javanese cosmology, water is both a blessing and a boundary, a living realm governed by Ratu Kidul, the Queen of the Southern Sea, whose sovereignty commands balance rather than defiance (Wessing, 2000; Kristianto et al., 2024). Building an unbroken wall against the sea thus becomes more than an act of engineering; it is a cultural provocation, replacing centuries of dialogue with a gesture of domination.

Ethnographic accounts reveal that fishermen in Demak and milkfish farmers in Sayung feel the loss not only of land but also of their ancestral rhythm, the daily tide work that once determined when to fish, drain ponds, or pray for calm waters (Suwito et al., 2020; Suryantoro & Soedjijono, 2018). For generations, coastal Javanese communities have practised a vernacular resilience, characterised by light bamboo houses, flexible tenure, and spiritual humility in the face of shifting tides. The state’s imposition of concrete permanence, however, replaces this fluid dialogue with the static logic of control (Santoso et al., 2021).

The conflict between permanence and impermanence thus becomes a philosophical issue. A wall that denies movement denies memory. To forget that coasts were once moving boundaries of coexistence is to misunderstand the moral dimension of engineering itself. True resilience in such a landscape requires cultural literacy, the ability to hear what the sea has long taught those who live beside it (Wessing, 2000; Purnomo, 2024).

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4.2        The Ethics of Protection

Engineering is never morally neutral. When a wall saves one village but floods another, it becomes an ethical artefact (Liss et al., 2025). In Bedono, dry floors and renewed dignity testify to protection’s promise; two kilometres away, diverted currents clog small harbours with silt, suffocating livelihoods. Such asymmetry demands ethical accounting: for whom does protection work, and who bears its unintended harm?

The literature on climate justice warns that adaptation projects often redistribute vulnerability rather than eliminate it (Torabi & Dedekorkut-Howes, 2020; Nurul et al., 2025). Managed retreat frameworks demonstrate that coastal protection is not a binary choice between walling and withdrawal but rather a spectrum of shared decisions that require fairness, consultation, and long-term governance (Liss et al., 2025; Mycoo, 2013). In Indonesia’s deltaic settlements, such decisions rarely reach those most affected—the informal fishers, shrimp farmers, and laborers who do not appear in consultancy reports.

Ethical engineering, therefore, begins with inclusive process design: participatory mapping, livelihood compensation, transparent criteria for relocation, and continual feedback loops that ensure protection does not become privilege. Following Jonas’s “imperative of responsibility”, engineers must act so that their works remain compatible with the permanence of genuine human life on Earth (Nurul et al., 2025). The Seawall’s moral success will depend less on whether it holds water than on whether it upholds dignity.

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4.3         Memory, Monument, and Modernity

If Daendels’s Great Post Railway once symbolised mastery over space, the Great Java Seawall risks symbolising mastery over time—a bid to freeze a coastline that has always spoken in centuries. The earlier Railway connected the empire to geography, while the new wall connects ambition to geology. Both reveal what power seeks to immortalise.

Across Java’s coast, the interplay between memory and space challenges the idea of walls as inert structures. Coastal temples, tidal shrines, and sacred squares, such as Alun-alun Kidul, embody an indigenous understanding that places evolve through erosion, ritual, and renewal (Santoso et al., 2021; Suryantoro & Soedjijono, 2018). When infrastructure erases these dialogues, it erases meaning. However, it need not. A wiser seawall could become a living memorial, its kilometres inscribed with the names of lost villages, its promenades planted with mangroves and community art that commemorate displacement as shared history (Purnomo, 2024; Reid, 2015).

Such memorialisation reframes protection as remembrance rather than conquest. It transforms engineering into storytelling, inviting each generation to reflect on what was protected, what was sacrificed, and what lessons endure. In this form, the Seawall ceases to be an authoritarian line and becomes a pedagogical landscape, teaching humility alongside hydrology.

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4.4         The Engineer’s New Oath

The moral geometry of climate engineering ultimately converges on the engineer’s conscience. To design a wall that breathes ethically, civil and environmental engineers must embrace a new professional covenant, a Hippocratic Oath for the planet:

“I will design with foresight, govern with compassion, and remember that sustainability is not a calculation but a covenant.”

This oath embodies the emerging philosophy of governance as engineering, in which technical skill is inseparable from moral judgment (Liss et al., 2025; Torabi & Dedekorkut-Howes, 2020). It demands that protection evolve through continuous monitoring, transparent budgeting, and public accountability. It also insists that individuals lacking political or financial capital often perceive the invisible coast as visible within decision-making frameworks (Nurul et al., 2025; Mycoo, 2013).

Within this covenantal framework, the Great Java Seawall serves as a test case for moral engineering. If it can transform defence into dialogue and resilience into remembrance, Indonesia will have built more than a barrier; it will have built a new civic ethic, one that redefines progress as the capacity to coexist. For the first time since Daendels charted the Great Post Railway, infrastructure could again serve as a moral frontier, measuring not how high we build, but how wisely we choose to stand.

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4.5         The Moral Equation and the Path Forward

The four dimensions are cultural stewardship of water, ethical inclusion in protection, memory-informed modernity, and oath-bound engineering. Reveal that the Seawall’s geometry is not only structural but also moral. Its actual design lies in how it balances faith and foresight, authority and empathy, and permanence and remembrance.

A resilient future for Java will depend on whether national planners can translate these ethical coordinates into policies that share risk fairly, govern adaptively, and honor local cosmologies as living frameworks of sustainability. The wall, then, is no longer a line that divides land and sea; it is a mirror reflecting how a civilisation understands its duty to both.

When the tide tests the wall, it will also test Indonesia’s conscience.

5         Epilogue: The Wall and the Wave — A Civilization’s Climate Covenant

5.1        A Historical Hinge, a Future Hinge

Two centuries separate Herman Willem Daendels’ Great Post Railway across Java and today’s Great Java Seawall, yet both lines mark a hinge where history meets horizon. Daendels’s De Grote Postweg bound space, governance, and labor into a single infrastructural artery, redrawing Java’s political and social topographies at immense human cost (Harahap et al., 2024; Zamani, 2022). Tens of thousands perished carving a colonial ribbon more than a thousand kilometres long. That road connected the island, yes, but it also etched the first scars of forced modernization into the archipelago’s soil.

Today, another line is being drawn, not across the land, but along the edge of the sea. Where Daendels conquered distance, the modern engineer confronts the depth of time, ethics, and planetary consequence. The Great Java Seawall may be the Daendels Railway of the climate century: a monument not to empire but to endurance. Our generation attempts to tell the ocean, “We will stay.” However, the wiser message—the one the sea might respect—is “We will stay with you.”

In this moral inversion, the Seawall binds conscience to coastline, translating resilience into a form of governance that must outlast climatic and political tides. The parallel is not chronological but ethical: a line once built to command space now becomes a boundary that demands renewed responsibility toward water, memory, and the communities whose futures depend on how well we learn to move with the wave rather than merely ward it off (Kristianto et al., 2024). The epilogue thus invites the nation to stay with the sea, not simply ahead of it.

 

5.2        A New Legacy: Stories as the Load-Bearing Layer

If Daendels’s railway carried soldiers, goods, and imperial ambition, the Great Java Seawall must carry stories—not as decoration but as load-bearing knowledge guiding design and governance. Each segment rising from the shore bears not only steel and silt but also the narratives of fishers, farmers, and children who may never walk again on the dry land their grandparents knew.

The moral claim that protection should be based on a covenant rather than conquest resonates with scholarship that views social memory and cultural engagement as indispensable design inputs for coastal defence (Kristianto et al., 2024). The sea’s memory is not passive; it is a teacher whose lessons require humility from those who build and regulate its boundaries. A memorialised seawall, its kilometres named after vanished villages, its promenade shared with mangroves and community art, could unite ecological health and collective memory into a single, resilient architecture.

This vision aligns with climate-justice frameworks that call for embedding memory, cultural stewardship, and participatory governance within adaptation pathways, rather than treating protection as a merely technical task (Liss et al., 2025; Torabi & Dedekorkut-Howes, 2020). Thus, the Seawall’s truest reinforcement lies not in concrete thickness but in the density of stories it carries.

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5.3        From Monument to Movement: Reframing Engineering’s Core Aim

The epilogue pivots from a fortress mentality—“we “will protect at all costs” to a civilisational aim: to civilise through protection, not merely construct fortifications (Liss et al., 2025). Blueprints must begin with justice, not just geometry. Engineering should align with social equity, ecological integrity, and adaptive governance that responds to shifting climates (Liss et al., 2025).

In this sense, the Seawall becomes a platform for learning, a living laboratory where communities test governance arrangements and iterate design as a shared practice (Nurul et al., 2025). Eco-hydraulic literature reinforces this move from monument to movement, advocating for structures that integrate ecological feedback and stakeholder participation (Prayoga, 2025).

Let this be the century when civil engineering returns to its first principle to civilise, not merely to construct; when the ocean ceases to be an enemy and becomes a teacher. For in truth, no wall can outlast the wave, but a people united in wisdom can move with its rhythm.

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5.4        A Cathedral of Responsibility: Engineering as Governance Practice

Endurance depends on more than structural robustness; it relies on institutions that uphold transparency, maintenance, and accountability in the face of uncertainty. The “cathedral of responsibility” envisions governance as an explicit design constraint, coupling engineers, ecologists, and communities in a continual process of decision-making and revision (Nurul et al., 2025).

Here, protection gains legitimacy through participation and equitable risk-sharing, including those without formal voice. The Seawall thus becomes a living system, both organisationally and physically, aligning technical performance with social legitimacy and intergenerational justice. A cathedral of responsibility does not worship certainty; it sanctifies shared fate, acknowledging that the coast’s health depends as much on social contracts as on sediment dynamics (Nurul et al., 2025).

If Daendels’ Railway bound Java’s towns, this wall must bind Java’s conscience. It should stand not as a fortress but as a promise: that engineering, reborn through empathy, can serve humanity without conquering it.

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5.5        The Ocean as Teacher: Humility, Adaptation, and Mutuality

The epilogue’s ethical refrain, “we will stay with you,” reorients climate engineering toward a partnership with the sea, treating depth as a teacher rather than a threat. Research on adaptive governance shows that resilience thrives when institutions recognise the sea’s agency and communities engage in learning that accommodates continuous coastal change (Torabi & Dedekorkut-Howes, 2020; Mycoo, 2013).

The Great Java Seawall’s modularity, grey-green interfaces, and integrated flood-management systems embody this humility-in-action: a design ethos that invites the sea into a cooperative state of stability. Its legitimacy rests on how it accommodates ecological feedback, social needs, and economic realities across generations (Prayoga, 2025). In this framing, the wall becomes a learning organism, self-correcting, inclusive, and resilient as science and society evolve.

If it endures, let it stand not as a monument to fear but as a cathedral of responsibility, built by hands that understand both the fragility of coastlines and the sanctity of coexistence.

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5.6        Synthesis: A Civilization’s Climate Covenant

From Daendels’s Railway to Prabowo’s wall, from the dust of empire to the tide of climate, Indonesia again stands at the meeting point of history and horizon. Here, in the narrow space between concrete and coral, the next century of civil and environmental engineering begins not with a blueprint, but with a prayer.

The Seawall’s success will be measured not by its height or cost, but by how well it embodies a shared covenant between humans and the water. The cadence of the sea, its tides, erosions, and renewals must be listened to and woven into design and governance. When the water speaks, the response must be adaptive and inclusive; when people listen, the coast becomes both teacher and partner in resilience.

The Great Java Seawall thus symbolises a shift from imperial control of space to democratic responsibility for coexistence. Its endurance will reveal whether civilisation has learnt to balance the thirst for safety with the sea’s insistence on life, memory, and regeneration. The epilogue, therefore, reframes infrastructure as a moral covenant, an enduring practice that binds a nation’s history to its future, converting a line along the shore into dialogue across generations, and inviting engineers to become custodians of both water and memory (Harahap et al., 2024; Zamani, 2022; Liss et al., 2025; Torabi & Dedekorkut-Howes, 2020; Mycoo, 2013).

 

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