Development of A Green Least-Cost Generation Expansion Plan For Kenya

Abstract

The power generation sector is a huge CO2 emitter that precipitate climate change. In mitigating CO2 emissions/climate change, the study developed a green least cost generation expansion plan (GLCGEP) as a substitute of the previously proposed carbon intensive 2011-2031 least-cost power development plan (LCPDP) for Kenya. The study involved, determining the green candidate plants for GEP; deriving an optimal GLCGEP based on the green candidate plants and establishing the techno-economic characteristics of the GLCGEP and LCPDP. A generation cost model was formulated for selecting the green candidate plants based on the levelized cost of electricity (LCOE); the selected green candidate plants, the demand forecast, the existing and committed plants were simulated in the Wien Automatic Software Package (WASP) IV model and the optimal GLCGEP derived. The techno-economics of the optimal GLCGEP and the LCPDP were evaluated in a comparative study. The green base load candidate plants for GEP in Kenya were namely; 140 MW Geothermal, 140 MW low grand falls hydro, 300 MW Wind, 1000 MW Ethiopian imports and 60 MW Mutonga hydro. They are characterized by low levelized cost of electricity (LCOE) of US$ 6-13 cts /kWh. Suitable green peaking plants was mainly the 100 MW Solar PV with a higher LCOE of within US$ 15-30 cts/kWh. The 1000 MW nuclear and the 180 MW GT-Natural gas plants were complimentary base and peaking plants respectively The GLCGEP generation capacity was projected to grow from 1382 MW in the base year to 19828 by 2031. Out of the total capacity, 40.8% is geothermal, 19.5% wind, 11.1% Ethiopian imports, 10.9% natural gas, 9.1% nuclear, 5.2% hydro, 2.3% HFO and 1.0% solar PV. The generation system was expected to supply 7721 GWh to 105766 GWh by 2031. The GLCGEP and the LCPDP capacities depicted 25% and 28% average reserve margins respectively; the later providing excess. By 2031, the GLCGEP; 78% green almost twice the LCPDP at 49% was projected to accrue a total of 20.2 Mt CO2 avoided CO2 emissions estimated at US$ 62.9 million carbon credits besides other invaluable green fringe benefits. The GLCGEP was also more feasible as showed more revenues approximated at US$ +2.16 billion NPV unlike the US$ - 0.31 billion for the LCPDP. The study demonstrated a feasible future for green-based generation with security of supply and sustainable development. Therefore, the study recommends that future studies be carried on modeling power system stability with high Wind and Solar PV integrated in Kenya.