Bioenergy - Realizing the Potential

Chapter 16

Wood Waste Cogeneration in Kumasi, Ghana

Dominic Derzu, Henry Mensah-Brown and Abeeku Brew-Hammond

16.1. THE INCREASING ENERGY DEMAND IN GHANA

The demand for power has increased significantly in Ghana over the years, resulting

in an annual power supply crisis since 1983. Thus the country has had increasing

difficulties in meeting the demand of domestic and industrial consumers, and export

commitments to neighboring countries. In fact, Ghana used to be a net exporter of

electricity but this situation has changed and the country is now a net importer of

power from la Coˆ te d’Ivoire. Hence there is an urgent need to look for alternative

sources to widen the power generation mix in the country, while also improving the

reliability of supply.

The hydropower plants at Akosombo and Kpong, and the recently added thermal

plants at Takoradi, together with the import complements from la Coˆ te d’Ivoire,

cannot meet the power demand for various user categories. The short supply of

electricity throughout Ghana forces many small and medium enterprises (SMEs) to

run expensive standby diesel generators to meet their energy requirements. The

government has decided to remove all the latent hurdles preventing private sector

involvement in the energy sector and the economy has been liberalized, resulting in

an influx of new investors.

Biomass resources from the agricultural and forestry sector s are readily available

for energy purposes along with wind and solar resources. The limiting factors for the

utilization of these energy sources include location, availabil ity and sustainability

of the resources, fuel handling and preparation, and opportunities for fuel flexibility.

In addition, the technology choice and its reliability, as well as the overall economics

of energy projects are particularly important, especially now that the tariff regime is

being reviewed towards better economic efficiency.

This chapter looks into the potential for wood waste utilization for power gene-

ration in Kumasi, Ghana. The specific conditions for utilizing wood waste from

wood-processing industries in cogeneration are presented for a project. The feasi-

bility of the project is discussed under the framework of CDM, which also includes

the boundary and baseline for the project, the carbon offsets as certified emissions

213

Bioenergy – Realizing the Potential

ß 2005 Dr Semida Silveira

Published by Elsevier Ltd. All rights reserved.

reductions (CERs) expected, and the outstanding issues that need to be solved to

allow full implementation of the project. The project seeks to make use of abundant

resources currently perceived as a nuisance to the environment, while also offering

an opportunity for power generation.

16.2. AVAILABILITY OF WOOD WASTES IN GHANA

The annual cut allowance of forests to the wood-processing industry is 1 million m

3

and the Forestry Commission is responsible to ensure compliance to this law.

However, the limit was not seriously observed until the enforcement of the ban on

chainsaw operations in the country in 2000. More than 50 per cent of the cut allow-

ance is attributed to sawmills in Kumasi, the most industrial timber city in Ghana.

In fact, of the approximately 100 sawmills established in Ghana, 67 are in the Ashanti

region, of which 65 are located in Kumasi and surroundings.

The wood waste associated wi th sawmilling activities in Ghana is of two

categories. There are forest residues (leftovers from forest cutting) and residues from

the wood-processing mills. The latter group of residues is envisaged for use in the

cogeneration project presented here. Experts of the forest and wood industry in

Ghana classify the volumes of residues from commercial wood-processing opera-

tions as shown in Tabl e 16.1. Of the different types of wood waste listed, only the

sawdust has no competitive use.

16.3. FEASIBILITY OF A COGENERATION PROJECT IN KUMASI

The timber industry in Ghana comprised about 134 wood-processing firms in 1996

(S-B. Atakora, 1999). It is the fourth foreign exchange earner in the country after

Table 16.1. Estimates of volume of residues from wood-processing

activities in Ghana

Type of wastes

% of the

total log input

Volume in

m

3

SWE

Off-cuts 20 200 000

Bark, slabs and edgings 20 200 000

Sawdust 15 150 000

Total 55 750 000

Source: Kumasi Wood Waste Cogeneration Feasibility Report, 2001.

214 Bioenergy – Realizing the Potential