Financial viability of agroforestry for bioelectricity generation on various farm types in the Western Cape, South Africa

Abstract

ABSTRACT South Africa relies on fossil fuels for generating more than 80% of its electricity. While projections of known reserves indicate sufficient coal for 114 years, air pollution from coal power plants causes serious environmental damage. The production of lignocellulosic biomass for generating bioelectricity seems to be an appropriate option in order to become less dependent on fossil fuels. In this article, the potential for producing this type of biomass was investigated for the Cape Winelands District Municipality (CWDM). First, the potential area for production in a Short-Rotation Coppice (SRC) system was identified by means of Geographic Information Systems (GIS). After assessing suitable tree species and their productivity rates, an annual supply of about 1.4 million tonnes per year could be expected, using exotic species such as Eucalyptus cladocalyx. Three scenarios were assessed by means of farm modelling. The first scenario describes woody biomass production as a single production activity on fynbos/uncultivated land, not competing with other agricultural activities. In the second scenario, biomass production is introduced as an additional enterprise on a dryland winter-grain farm, typically in the rainfed grain- and livestock-producing Gouda/Hermon farming area. The third scenario describes biomass production in an intensive farming environment. Given the National Energy Regulator of South Africa (NERSA) tariff for bioelectricity, it can be concluded that woody biomass production in a short-rotation system, either as a soleproduction business or integrated into a farming business with other agricultural activities, can be economically and financially viable. Land values, however, have a large influence on viability.