[bionet.technology.conversion] Biogas: Views from Experts' Group Mtg.

P2269@com.qz.se ("ENG-LEONG FOO ", MIRCEN-STOCKHOLM) (03/28/89)

This is an excerpt from the report of the Experts Group Meeting
on Energy for Rural Areas of Africa which was published in the
UNITAR/UNDP Centre on Small Energy Resources Newsletter. Aug
1988, Issue 12.

B) Biogas
In Africa, biogas technology, though promoted by some organizations
(i.e. CRAT - African Regional Centre of Technology, Senegal),
has not been greatly exploited. This is mainly due to the high
initial investment costs which small farmers cannot afford. In
Africa over 80 % of installed biodigesters for household use
have been entirely financed by international or non-governmental
organizations or by the national government themselves.
  Nevertheless, in a few countries, particularly Kenya and Tanzania,
there has been a fairly wide diffusion of biodigesters and a
lot of information on results of exploitation is presently available
there. In both countries biodigesters are sold commercially and
there has been government encouragement of biogas projects. In
Liberia and Nigeria there have been some successful demonstration
projects.
  In Ghana, pilot biogas plants were built by the National Energy
Board, in an effort to find a feasible alternative to fuelwood.
  In Tanzania 120 Indian designed biogas plants were installed
between 1974 and 1983. In Senegal, some biogas units (less than
10) were installed by two non-governmental organizations. Both
of these projects were reported as unsuccessful because the programme
objectives were initially unclear and the user needs were noy
sufficiently examined.
  Technical problems, namely the vitrification ofashes and the
poor quality of the gas produced, have been found with the biogas
units (between 150 -400 kW) installed in the Ivory Coast and
Mali. Technical problems have continued to plague biogas projects
and there have been severe difficulties in bridging the gap between
research and application.
  The greatest problem associated with biomethanization is the
high proce of installing a biodigester. The cost varies according
to the type of biodigester, its size, and the materials used.
A Chinese-type digester of 10 m3 capable of providing enough
electricity and cooking of one family of 6 members costs on average
USD 1.500.
  Overall, technical and financial problems have meant that the
potential usefulness of this form of energy is largely overlooked.
A further disincentive has been the number off broken down and
deserted biodigesters to be found. This obvious evidence of failure
has discouraged rural people from considering biodigesters as
a source of energy.

Immediate Comment from E.L. Foo :
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Does anyone have first hand experience on the situation in Africa
and would like to elaborate more on the existing problems; maybe
also on why a success in one country has been a failure in another.