Burn better, cook faster, save $$: the quest for an efficient African cookstove


By 2050, Africa will need 2.9 billion tons of wood per year to provide cooking fuel for its population, and according to the FAO it will require 771 million hectares of woody biomass cultivation to support that demand, and Africa only has 649 million hectares of forest if no one cuts any down in the next 35 years, say for urbanization or food production. And not every hectare of forest in Africa is accessible for firewood, or makes the hardwoods that make for good burning charcoal, anyway. Just saying.

In Africa, the overwhelming use is cookstoves, and for a generation now, companies and organizations have been handing out LPG or ethanol cookstoves trying to move Africa to a new energy source for cooking. There’s been limited success.

The Humble Cookstove at the heart of the problem

Peter Scott has been working in Africa in the cookstove field for 20 years, and tells the tale.

70-80 percent of cooking fuel comes from biomass in sub-Saharan Africa, and in terms of charcoal it is exploding, because Africa’s population is exploding and especially in the cities, and people burn charcoal there instead of wood. There’s a 4 percent increase in the cities every year.

The market is for solids. Ethanol hasn’t scaled, and the supply chain for LPG isn’t there, and LPG fuels cost 2-3 times as much anyway, and is not economical for the traditional meals that have to be cooked for a long time, it’s more popular with the breakfast meal, for boiling tea.

I came to Africa in 1990 at the age of 20 and I worked in the Congo. Since 1997 I’ve been working in cookstove design, and I’ve been a consultant to USAID and Practical Action. I spent years trying to stop the use of traditional cookstoves. But finally I started my own operation in 2011, because there was this gaping need to develop a fuel efficient cookstove where we can stop the bleeding while we develop other fuels.

The problem with charcoal is that it is so inefficient compared to wood. A kilo of charcoal will produce twice as much energy as a kilo of wood, but it takes 8 kilos of wood to make that charcoal, so when someone moves to the city, they are increasing their consumption of wood by four times.

That may be an exaggeration, or it may not. Sources are all over the map when it comes to the conversion rates. The FAO cites a 5X conversion rate, and we’ve seen an NGO referring to a 10X conversion rate — a ton of wood to make just 100 kilos of charcoal. But almost everyone agrees that there’s twice the energy in a kilo of charcoal compared to wood.

Lots of black eyes in cookstove transformation

The cookstove transformation market is not well developed, and as Pater Scott tells us, “there are lots of black eyes”. Harry Stokes and his GAIA Foundation have labored tirelessly in the field over the years and have moved a lot of units. Femi Oye had an organization selling a rival ethanol gel cookstove. POET has been active as a foundation activity, and Novozymes was backing a venture for a number of years which did not come off well in the end.

Peter Scott knows the problems well.

It’s cost, in the end. An African family may be used to spending as little as $5 on a traditional cookstove, and then spends $30 per month on the fuel. We sell our fuel-efficient unit for $35 and you can save more than $15 per month on the fuel, and the payback is in 3 months, and could be less for a family using the cookstove for all three meals of the day. But it’s common to cook breakfast with LPG and other fuels, where you want to quick boil tea, and you are not cooking beans or meats — nothing that requires a lot of cooking time. So it depends on the usage, in terms of the payback, but it is never more than 3-4 months.

So, if the stove cuts the fuel demand by half, and there’s payback in just a few months, why isn’t everyone in Africa buying one?

The market adoption backstory

Well, Scott’s company, BURN manufacturing, isn’t exactly a start-up at this stage. They’re sold 300,000 units to date, primarily in Nairobi, but now expanding throughout East Africa, and units are sold in all 42 counties of Kenya. The company raised $4 million to establish its factory and set up distribution — and is raising capital now to expand to another manufacturing site in Ghana and thereby to expand to West Africa. But why is the demand in the hundreds of thousands instead of the millions? Comes down to finance. As Scott says:

Do they have the cash on hand? 75 percent of the sales are in cash. Microfinance credit is widely available, but they focus on bigger purchases, not $35 cookstoves. overall there are 600 retail points for the cookstove — and many of them support a pay-as-you-go option.

It’s a replacement market. 98% of the customers are switching from the older type of charcoal to ours, and there’s not always the money available to make the investment, even with the quick ROI and the health benefit that comes from reducing the amount of charcoal that’s being burned.

The technology backstory

How does the unit work? It comes down to precision engineering that been applied perhaps for the first time to a widely-used but low-tech item.

No, it’s not low-tech, says Scott. It’s highly complex, it’s just not been subjected to science. We have a very low mass combustion chamber, we worked on air to fuel mix, heat intake, heat transfer. It’s a bunch of subtle things, and we had a DOE grant to develop a new stove, and each part of the stove takes 5 PHDs. But no one had really paid attention to this form of combustion as an opportunity for every savings. When you visit the ministries, they think about coal and liquids, and they talk about geothermal, wind or solar but people hadn’t done anything about changing the cookstove system except trying to change the fuel.

The prospects are bright, says Scott, or BURN’s horizon.

We found that 70 percent of everyone knew about our system and 30 percent are planning to buy one, and in Kenya alone there are 50,000-100,000 per month sales of the old systems. 

Hence the equity raise. But it comes at surprisingly low costs, compared to building bioenergy projects for liquid fuels. They are raising $1.3 million for local expansion, another $2.5 million for the West African expansion, and a working capital facility. To date they have raised $12 million via OPIC and GE, and $3 million in grants — taking in all of the technology development, construction, and deployment.

Big market, few competitors

Perhaps most interesting in all of this is the lack of interest in forming companies to chase this market. The rates of conversion from. say, conventional electricity to solar are nothing like the 30 percent conversion rates that Scott touted.

It may comes down to energy fashion. As Scott notes:

The cookstove market is crowded, that’s the perception. But look at solar there are like 140 companies working in East Africa in that field, while there are only 3 cookstove companies that are players at all.

The value proposition for prospective players is simple, and the market is wide, but the technology hurdle is not without drama.

You have to deal with solid fuel, and it’s not going to be standardized what they use. It’s high temperature, there’s going to be 1000C in there, so you need materials that can withstand the heat. You need clean emissions, and you need to get the price point which is around $30, you need durability, and you need something that works in everyday life, not just in the lab, and you need to test that for a year to understand how your alloy choices, for example, will change the overall picture.

Cutting the energy usage by half doesn’t solve all the problems of urbanization in Africa. If it takes 8 pounds of charcoal to make a pound of charcoal and you get twice the energy of wood — the urban shift is still powering a 4X increase in wood demand, and Africa can’t sustain that. Cutting that in half doesn’t, of itself, solve the problem, But, as Scott points out, it buys time for other energy options to emerge. And cuts emissions.

We might also point out one thing.

Gathering firewood may the most dangerous occupation ever handed out to small children. The more biomass that’s used, the farther afield they are going to scour for it. Farther from home means closer to trouble — and violence against young girls is on the rise in Africa, and collecting firewood is a driver. We’ve noted these trends in highlighting the push to use alternatives like liquid ethanol or ethanol gels — and all those benefits apply, and alcohol fuels represent a tremendous opportunity.

But for those seeking a low-cost, traditional solution — that is, the everyday African looking to save money not learn a new drill for cooking family meals — efficient cookstoves provide a real opportunity to make a better world — and governments might take a pause from all the programming aimed at getting people to stop using cookstoves, and simply improve them while the next generation of energy technology is in development or the infrastructure of new energy supply is being deployed.