Biomass comprises of any organic matter from a living organism. Biomass is the widest class of renewable energy and can be categorized using various methods. Biomass energy can be categorized based on its physical state as solid (charcoal, fuelwood, and animal waste), liquid (biodiesel, straight vegetable oils, ethanol) and gas (biogas) or in relation to its source as residue (by-products from agriculture, urban areas or forestry), energy crops (dedicated plantations) or natural resources (woodlands, grasslands, water plants, forests).
Biomass can be converted into energy through various conversion routes. Considering the conversion efficiencies and the competitiveness of the energy output relative to other forms of energy, the use of biomass for direct heat generation or electricity will remain the most preferred.
Of the wood harvested in Turkana, 30% is converted into charcoal and 70% is used directly as firewood. Charcoal is mainly used in urban areas and firewood in rural households. There has been a shift in the main source of income in Turkana County, from the sale of livestock and associated by-products (22%) to the sale of charcoal (38%) and wood products (18%). The poorer community members of Turkana derive as much as 72% of their income from the sale of firewood and charcoal. The main markets for firewood in Turkana County are the refugee camps, with demand estimated at 118,456 tons per year[1]. Installation of improved cook stoves in five schools has been undertaken by the county government.
Overall, Turkana County has a biomass surplus, but distribution is skewed with Turkana West, Turkana North and South counties having the most biomass in the form of prosopis. The major biomass consumption centers within the county are the urban centers of Lodwar, Lokichar, Kakuma, Lokichogio and Lokitaung among other large centres. The County currently exports biomass to neighbouring counties and supplies charcoal and fuelwood to the neighbouring counties.
In Turkana County, the common biomass conversion methodologies are direct combustion (i.e. firewood) and pyrolysis (i.e. charcoal). The firewood is mainly collected from the local indigenous forests. The county has one gazetted forest and 20,000 Ha of non-gazetted forests – dense bushes and woody cover as shown in Figure 4-1.
[1] Rapid Assessment of Natural Resources Degradation in Areas Impacted by the Refugee Influx in Kakuma Camp, Kenya Technical Report November 2018 (FAO, WB, TerrAfrica)
Figure 4-1: Land cover and biomass primary resources
The case of Prosopis Juliflora (Prosopis)
A major source of biomass within the County is the invasive Prosopis Juliflora that covers a large acreage of the county. The plant was introduced in Turkana in the mid-1970s as part of Kenya government’s policy and Norwegian Agency for Development Corporation (NORAD) to mitigate the effects of drought and improve livelihoods in the drylands[1]. However, it has now invaded riverine areas, watering points and major grazing sites leading to it being termed ‘invasive’ attributed to this uncontrolled growing habit. Prosopis tends to form dense, impenetrable thickets, associated with unfavourable impacts such as blockage of roads and access paths, and invasion of grazing areas.
It does have positive impacts such as provision of fuelwood, shade, medicine, construction materials, forage, and for erosion control. This sets the stage for prosopis management strategies, which should emphasize on the positive aspects of the species especially using it as a source of energy. Prosopis produces good quality fuel of high calorific value of about 4,216 kcal/kg which burns well even when freshly cut due to its high carbon content and levels of lignin. Prosopis also produces high quality charcoal of about 7,000 kcal/kg in calorific value. Prosopis quantity in Turkana County is high but unquantified. A GIS analysis was carried out to map the areas with high quantities of prosopis, its proximity to areas with large human settlements and its accessibility to the main road network. The map shown in figure 4-2 highlights the areas that have high Prosopis occurrence. From the map, it is evident that the areas around Kakuma, Lomeyan, Lokichar and Kataboi – Ngissiger have the highest potential of utilising Prosopis for energy. These areas have a high population density and are accessible through the main roads linking the County. The roads will make both the transportation of equipment needed to convert the Prosopis to modern energy as well as transportation of the raw material easier. Production of charcoal and generation of electricity offers new opportunities for communities that live in these Prosopis rich areas. Suitability and sustainability of Prosopis as a potential source of biomass energy can be assessed from four (4) perspectives; availability, conversion potential, fuel quality and potential for productive use (e.g. cogeneration).
[1] Esther M. & Brent S., (2005), Invasion of Prosopis juliflora and local livelihoods: Case study from the Lake Baringo area of Kenya. ICRAF Working Paper – no. 3. Nairobi: World Agroforestry Centre
Agricultural and animal waste
Turkana County is not a traditionally farming county. No data exists on volumes and use of agricultural wastes. Availability of animal wastes can be estimated from the number of animals available in the county. However, given the pastoralist nature of the community availing the waste at centralized locations would be a challenge and would make it unattractive for any commercial venture planning to convert the waste to energy, except in the cases of large herds in centralized locations.