Biogas is a clean and renewable form of energy
accessible to low-income households through
anaerobic digestion of readily available organic
waste. The objectives of this desktop study were to
investigate the feasibility of biogas use for substitution
of presently used solid fuels in rural and periurban
households, the subsequent health co-benefits,
and the constraints to adoption of domestic biogas
technology in South Africa. The energy demand
of low-income South African households for cooking
with fuelwood was found to be 27 MJ/day and
the total energy demand 68 MJ/day. This is equivalent
to 2 500 L/day/household of biogas for cooking
and 6 250 L/day/household of biogas for complete
substitution of conventional domestic fuels.
Complete substitution of fuelwood used for cooking
and household fuelwood use with biogas can result
in the avoidance of 43% and 85.4% respectively of
total disability adjusted life-years lost (702 790) and
mortalities (22 365) from indoor smoke as a consequence
of solid fuel use. Approximately 625 000
households in South Africa can potentially benefit
from bio-digester fed with cattle and pig waste, on
the basis of livestock numbers. It is infeasible to
operate a domestic bio-digester fed solely with
human waste, chicken waste and food waste
because of insufficient feedstock. Non-sewered
households with access to on- and off-site water
supply generate sufficient greywater for feeding a
domestic bio-digester for cooking purposes. This is,
therefore, recommended over the use of drinking
water.