Researchers from the School of Engineering at Trinity College Dublin (TCD) recently completed a research project in Malawi in Africa to generate electricity from portable biomass stoves in order to charge mobile phones and LED lanterns.
The researchers carried out the project, which was funded by Irish Aid, Intel and the Irish Research Council (formerly IRCSET). They integrated a thermoelectric generator with a cooking stove, with the generator having the capacity to deliver small amounts of off-grid electricity.
Working with the NGO Concern International, the researchers have specifically designed the generator to be used with low-cost stoves that are produced by women’s groups in rural areas of Malawi.
The results of their research have recently been published in the journal Applied Energy.
The stove works by generating electricity from the heat of efficient biomass cook stoves.
Currently, around 2.5bn 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.
The electrical generator works by using a thermoelectric generator that converts heat directly into electricity using the thermoelectric effect. The heat source is the fire in the cooking stove and the heat is dispersed using a specialised fan and heat sink system. The heat is then extracted from the stove using collecting rods that also act as a grate to improve combustion.
The electricity is then used to power a low power fan and specialised charge control circuitry, with the excess power being stored in a rechargeable battery.
According to the TCD researchers, 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, lights and radios.
Tests carried out in TCD’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.
Apparently this is sufficient electrical energy to charge a phone and to charge a LED lantern.
Field trials were carried out by Trinity’s energy researchers in collaboration with Concern Universal in Malawi where households tested the new technology for three months.
Open access to intellectual property
The generator is intentionally not being patented and all intellectual property is open access.
Dr Tony Robinson, the principal investigator from TCD said that developing a technology for the developing world that is inexpensive and sustainable is a challenge.
“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 craftspeople,” he said.
Former Irish president Mary Robinson, who is chairperson of the Global Leaders Council, viewed the cooking stove on a visit to Balaka in Malawi last month.
Check out the video here of the TCD researchers in action in Malawi.