Centre for Energy, Environment and Sustainable Development
CEESD partners GlobalResolve in ‘twig light’ dissemination in Ghana
24 – 27 May 2010
and GlobalResolve have started demonstration of twig light in two
communities in Ghana – Dormeabra and Akawli in
Asante Akim and Yilo Krobo district respectively. The device,
invented by Michael Pugliese of Arizona State University, consists
of a thin thermoelectric generator sandwiched
between a heat source and a heat sink. The heat sink is
connected to cold water while the heat source is connected to
burning coal or charcoal. The temperature difference created by the
heat source and the heat sink provides power that drives the
generator. The device is able to generate 5 volts of electricity
which is enough to power LEDs and enough to light a room. Several
prototypes of the twig light have been demonstrated at Dormeabra and
Akawli. Most participants said they would buy a twig light if it
fell within the range Gh˘ 10 – 15. A few quoted Gh˘ 5 as an affordable
price for the twig light.
Kingsford Agyekuma, a teacher at Dormeabra Junior High
School, suggested the development of supports for the twig light. He
also asked the designers to develop materials capable of conserving
heat for longer periods.
Akawli, a community forum was held to solicit comments and
suggestions on ways of improving the design. Participants were also
asked to suggest the maximum price they would consider affordable.
Selected households were also given the device for use. CEESD
members would be visiting beneficiary households every month to
collect information on the performance of the twig lights as well as
concerns raised by the households. CEESD and GlobalResolve believe
the twig light technology could be a replacement to solar PV
especially for small load applications in off-grid communities in
sub-Saharan Africa. The twig light has no moving parts inside the
generator, is relatively cheap, and most of the components can be
fabricated and assembled locally in sub-Saharan Africa.
The Twig Light can run on any available fuel – wood chips, twigs,
charcoal, gel ethanol, among others. According to Mark Rogers, the
Head of GlobalResolve, the major challenge is to produce a portable,
affordable, and reliable design that can easily be mass
produced/assembled locally in Africa.