REview: ACE 1, Ultra-Clean Biomass Cookstove

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African Clean Energy is based in Lesotho, southern Africa, with branches in Cambodia and Uganda.
ACE 1 in Uganda
ACE 1 in Lesotho
ACE 1 in Cambodia
ACE 1 in Cambodia
ACE 1 in Lesotho
ACE1 Factory in Lesotho. More than 30,000 ACE stoves have been manufactured and put into use around the world. ACE is at work on more improvements and broadening distribution of the cookstoves.
ACE 1 in USA. The author’s outdoor kitchen—cooking fritters efficiently with wood via the ACE 1.

Worldwide, roughly one in three meals are cooked by burning biomass—most often wood or charcoal. But traditional fires are problematic, exacerbating deforestation and air pollution, and causing health issues. In Central America, I often see open cooking fires in one corner of simple homes. The walls and ceilings in that part of the building are coated with black soot, which also likely permeates the lungs of the residents. And I see the poor rural dwellers cutting down native trees because they need many large pieces of wood to fuel their inefficient open fires.

More efficient ways to burn wood for cooking have been developed, including “rocket stoves.” Aprovecho, a nonprofit focused on sustainability, was key in developing this technology, which in its beginning, was a horizontal tube connected to a vertical tube, with specifically proportioned parts. These stoves create an airflow and burning pattern that consumes small pieces of wood efficiently and cleanly.

Until recently, most rocket stoves were hand-built on site, out of metal or masonry. This was a low-tech and relatively low-cost approach, but limited to those who had some fabrication and building skills. Now, African Clean Energy (ACE) is promoting wider use and adoption of this technology via its integrated, manufactured product, the ACE 1—a solar-powered, forced-air rocket stove with a single vertical chamber.

ACE has refined the basic rocket stove design, replacing the elbow and pipe size ratios with a six-sided, fire-brick-lined vertical cylinder and a fan, run by a lithium battery that is recharged by a small PV module. The fuel is a handful of small, dry twigs and wood scraps. Once the fire is started, the carefully designed airflow facilitates the “rocket” of a fire. A rheostat controls the fan speed to regulate the burn rate, as does how much fuel is fed into the stove.

Once started, the stove burns cleanly and efficiently. The colleague who introduced me to the ACE 1 had two of them at his campsite. Just 2 to 3 feet above the stove, there was a clean nylon canopy—with no signs of soot.

The manufacturer estimates that the stove cooks with 15% to 50% of the wood required for an open fire. A shoebox-full of small twigs and wood scraps can cook a few days’ worth of meals. This is life-changing, especially for women in many cultures who previously had to spend significant parts of their day walking to gather fuel. And, instead of cutting down entire trees, only small scraps are needed to fuel the ACE stove.

ACE has made this product even more useful by adding a USB port to charge cellphones or other USB-powered devices. An upcoming version will include a second port. In one product, three very essential functions are served—cooking, lighting, and phone charging. It’s a brilliant application of renewable energy technologies.

When you see and hear rocket stoves start to burn—with a roar—it is impressive. But building a unit yourself is a large hurdle for many people. Though I’ve schemed about building a rocket stove for my homestead, it hasn’t happened. Ordering online and having an ACE stove a week later started a love affair with this technology and product. I look forward to getting more of these units, both for my homestead and for my developing-world work.

Comments (9)

bruce southerland's picture

Biolite, not biolit. We have used the wonderful biolite products for many years. A+ company and products.

gerard's picture

The biolit is not a great device. It is basically a glorified battery with a supposedly TEG charger? Very questionable product.

gerard's picture

See user grctec1 at youtube for our videos

as well in the later video you will see a 25 watt unit and a 100 watt unit all passive cooling no moving parts. With our new Board which we just finished Dc to Dc converter with a Full PLC with I/O wireless sensors
you can run a 50 watt Not nominal but actual power from a wood stove.
we call it rabbit ears built it will be called IPOWERTOWER 2 when it launches in January. I've been building and testing TEG system for the past 22 years. Thermoelectric's have been my life for 29 years.

bruce southerland's picture

Solar charged systems like the one in this article can be a more affordable option than thermoelectric stoves. Also gasifier top lit up draft (TLUD) stoves have advantages. IMO, the mimi moto is the best gasifier cook stove in the world.

Marc Fontana's picture

I like the mimi moto. How much does it cost compared to the thermoelectric Biolite? I watched the 2 min video of the mimi moto and I was surprised to see the demonstrator spray some clear liquid from a bottle onto the bio pellets and wood fuel before lighting it on fire. Is that another fuel? I also wonder about a stove which is being demonstrated using pellets as fuel. Are these pellets accessible to people in the developing world? As long as it can be operated with any readily available combustible biomass, that's fine, however, if you need special fuels, white gas, etc... you can't call it cleaner or sustainable.

gerard's picture

Hi Bruce,
Can't argue with you? But solar is not able to provide base load power like a TEG is especially when you know how to design with them. Solar is intermittent at best. TEG for this option is better.

bruce southerland's picture

See Biolite

gerard's picture

Great to know that solar is charging a battery. We have a unit that does the same thing. Our design runs from Thermoelectric power so every time you turn stove on it charges the battery. Unfortunately, if the sun is not shinning battery is not charging and the fan will not run. This never happens with our design. we can also charge a Cell phone at the same time and Boil water for safe drinking!

Marc Fontana's picture

I'm intrigued by your version with Thermoelectric charging Gerard. Where can I find out more about it?

Thanks.

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