Energy Researchers at Trinity, Engineer a Generator that provides Electricity from Cooking to Homes in Rural Malawi

Posted on: 25 February 2013

Energy researchers at the School of Engineering at Trinity College Dublin have just completed an Irish Aid, Intel and IRCSET funded research project that generates electricity from cooking stoves, providing lighting and phone charging in  Malawi, one of the world’s least developed countries. Promoted by Irish Aid and in collaboration with the non-governmental organisation, Concern Universal, the generator is specifically designed to be used with low-cost stoves now being produced by women’s groups in rural areas. The results have recently been published in the journal Applied Energy.

On a visit last month to Balaka in Malawi, a host of dignitaries, including former Irish president and chairperson of the Global Leaders Council, Mary Robinson, singer Annie Lennox and the President of Malawi, viewed the novel generating cooking stove on display and interest was expressed in the new technology. When the project commenced almost 17,000 cooking stoves had already been disseminated in the Balaka district of Malawi. More recently, Malawian president, Her Excellency Mrs Joyce Banda, has announced a commitment to 2 million clean cookstoves in Malawi by 2020 and the TCD technology could potentially generate electricity from each one of these.

The stove works by generating electricity from the heat of efficient biomass cookstoves. Approximately 2.5 billion people living in the developing world burn biomass (largely wood) as a primary energy source. Over half of those who burn biomass lack access to grid electricity and large numbers have no access to nighttime lighting, often resulting in complete darkness once the last cooking fire goes out.

The newly invented electrical generator utilises a thermoelectric generator (TEG) that converts heat directly into electricity by means of the thermoelectric effect. The heat source is the fire in the cooking stove and the heat is dissipated to the surroundings using a specialised fan and heat sink system. The heat is extracted from the stove using collecting rods which also act as a grate to improve combustion. The electricity is then used to power a low power fan and specialized charge control circuitry, with the excess power being stored in a rechargeable battery. The generator is capable of generating a maximum of around 6 Watts and the energy in the battery can then be used from a 5 Volt USB connector to charge mobile phones or lights and even radios.

Tests carried out in Trinity’s School of Engineering showed that over three one hour cooking periods, the stove was capable of generating and storing 8 Watt-hours of electricity. This is sufficient electrical energy to charge a phone and still have enough to charge a LED lantern. Extensive field trials were carried out by Trinity’s energy researchers in collaboration with Concern Universal in Malawi where households tested the new technology for 3 months, with very positive results.

The stoves proved successful and very well liked by the participant families. On collection of the data, all the participants spoke of the benefits of charging the LED lanterns and mobile phones from their stove. One participant in the field trial study said that  “she never dreamed that one day she would live in a house with electricity”. The generator is intentionally not being patented and all intellectual property is open access.

Commenting on the significance of the new technology as a vital generator of electricity in Malawi, Dr Tony Robinson, the principal investigator said: “In the developing world, coming up with a technology is not that tough since there isn’t much there to start with. Developing a technology which is valued, appropriate, sustainable and really inexpensive is a whole different story.  Although we are still learning, it looks like we have engineered something that ticks the right boxes and has massive potential to bring electricity to the rural poor for the first time. The next stage is to scale up, with around 300 prototypes which will be assembled by local craftsmen.”