Perspective: Biodigesters aren’t profitable? Why I changed my mind

For a long time, I shared a widely held doubt: are biodigesters really profitable? Yet the global potential suggests this is far from a niche technology. Estimates point to the potential for more than 150 million household biodigesters worldwide—including around 30 million in Africa—alongside opportunities for larger systems serving businesses and public institutions.

Having worked for several years with the Pro-ARIDES programme as an advisor in inclusive finance and local investment, I later joined the ABC Sahel team to support households using biodigesters to develop viable business cases. Part of my role is to assess household economic models, analyse costs, and look at whether the numbers genuinely add up. Spending time with biodigester users has challenged some of my own assumptions.

The conclusion I have come to is simple: biodigesters are not inherently unprofitable. More often, what determines the outcome is how they are used and whether households are supported in seeing them as productive investments rather than just useful equipment.

In many rural households, biodigesters are mainly used to produce gas for cooking or compost for household farming. There is nothing wrong with that, but when use remains at that level, the financial return will naturally appear modest. What interested me was understanding what happens when the same technology is approached in different ways.

One of the most common concerns I hear is that biodigesters are expensive, complicated, and slow to generate returns.

That reaction is understandable. An initial investment of between CFA 500,000 (€762) and CFA 800,000 (€1,220) is significant, particularly in rural contexts where disposable income is limited, and access to finance remains a challenge. But judging the biodigester only by its upfront cost misses the bigger picture.

A biodigester is not simply a household purchase. It can also be a productive asset. Like any productive asset, its value depends on whether it is used effectively. That became very clear during my project visits. One producer in particular changed my thinking.

Pousga, a young agropastoral entrepreneur in the Nakambé region, installed a 4m³ biodigester in 2022. When I first visited, I expected to find a fairly typical setup: some compost production, some household energy use, and modest practical benefits. Instead, I met someone who had built a business around the technology.

Pousga produces up to 40 tonnes of high-quality compost each year—far more than I would have estimated before seeing it for myself. Selling compost at CFA 100,000 (approximately €150) per tonne, he generates close to CFA 4 million (approximately €6,000) annually. For a rural entrepreneur, that is significant income.

What struck me was not simply the production volume, but the mindset behind it. Pousga had not treated the biodigester as an add-on or a subsidised household asset. He had organised labour, secured biomass inputs, planned production, and identified buyers. As he explained:

The biodigester itself did not create profitability. What made the difference was the way it was integrated into an economic activity with intention and discipline.

During this work, I noticed a clear contrast between households. Some use biodigesters in a practical but limited way. They produce gas for cooking, collect compost for their own use, and stop there. The system functions, but only at a fraction of its potential.

Others approach the biodigester much more strategically. They organise dung collection, ensure a regular biomass supply, organise labour, plan output, and consider who will buy what they produce. The difference is not really about the technology. Nor is it always about finance. It is often about behaviour, motivation, and whether households see the biodigester as something to use or something to build around. Pousga made this point bluntly when we spoke: “When you invest CFA 500,000 of your own money, you stay engaged. You think, plan, and optimise.” That may not apply in every case, but it does raise an important question about ownership and commitment.

Subsidies remain important for improving access, especially for households that would otherwise be unable to afford a biodigester. But access alone does not create impact. Where biodigesters are introduced without a clear understanding of their economic potential, or without support to think through how they will be used productively, they can end up functioning as useful but underutilised assets. This is where things become more complex.

A subsidy can reduce the financial barrier to entry, which is positive. But if ownership is not accompanied by planning, market awareness, or a sense of investment, the likelihood of strong economic returns may be lower.

On the other hand, even conservative scenarios suggest that the economics can be viable. A producer generating 20 tonnes of compost annually—using part of it to improve farm productivity and selling the rest—may still be able to recover the initial investment over time.

That shifts the discussion from whether biodigesters should be subsidised to whether they can also be financed as productive rural investments. For financial institutions, that is an important distinction.

Focusing only on profitability would also be too narrow. The biodigester creates value in several ways. It can reduce household energy costs, improve soil fertility, strengthen resilience to climate shocks, and help respond to growing demand for organic fertilisers. For farming households, those benefits matter.

What I saw on projects visits was not simply a technology producing compost or gas. In some cases, it was supporting broader changes in household livelihoods and agricultural productivity. That is why this conversation should not be limited to energy access alone.

Looking back on these experiences, I no longer ask whether biodigesters are profitable. I have seen enough evidence to know that they can be. The more useful question is whether the right conditions are in place for households to succeed.

That means more than installing equipment. It means building awareness, supporting business planning, improving access to finance, and helping producers connect with markets where opportunities exist. Technology alone rarely transforms livelihoods - People do.

Pousga is not the only producer I met who demonstrated what is possible, but his words stayed with me:

Perhaps that captures the issue better than any financial model. The question is no longer whether biodigesters can be profitable. It is whether we are ready to treat them as the productive investments they have the potential to become.