Renewable power, in particular hydropower and biomass, makes up a large share of existing energy production in Lesotho. The country, however, has to import almost as much (66MW) as it produces domestically (72MW) to meet the basic needs of cooking and space heating by the majority of the population in the rural areas. Still Lesotho has got abundant potential for renewable energy resources. Opportunities lie in the generation of solar energy, wind energy and hydro power to generate electricity and meet the current supply gap.
Except for a few days in the rainy season, the sun appears all day for 10.2 to 13.8 hours, and most parts of the country get 300 days of sunshine a year with required radiation that can be used effectively to produce electricity. The theoretical solar power reception in Lesotho is about 60 x 1012 kWh per year. This is equivalent to 5159 million tons of oil equivalent (mtoe) per year. With 14% solar-to electricity conversion efficiency via PV modules, usable energy is 280 KWh/m2/yr. Solar PV is seen as having a very high potential especially in rural electrification for off-grid installations in households, schools, hospitals etc. Due to very mountainous terrain and sparse population, grid extension is not viable in the southern parts of the country. Solar energy is also seen as a means for water heating and the government has embarked on a project to equip public buildings with solar heaters. Solar cookers and solar dryers are also discussed for rural households. An analysis undertaken by the Department of Energy indicates that about 30 per cent of rural households could afford solar PV if there is a financing mechanism (whereby owners buy on credit) in place.
Lesotho offers the opportunity to build one of the highest windfarms in the world, with more than 80% of its territory lying at least 1,800m above sea level. Estimates have ranged that there is the potential to generate over 6,000 MW of wind power in the foreseeable future. Wind is a potentially significant source of energy for Lesotho not only for its own uses, but as well for export to its neighbours which present higher energy demands. Despite the potential to be one of the world’s highest wind farms, Lesotho is susceptible to one of the highest rates of localised lightning strikes. Another concern is the ability of the aluminium composite blades to withstand the Mountain Kingdom’s icy (down to -20°C) winters. Ice accumulation is a problem that can worsen in low-wind scenarios, which impacts economic viability.
The Lesotho Highlands Water project offers opportunities for mid to large scale hydropower development and several studies have been conducted on possible pumped-storage plants as well. In most cases, the units are not operating at their full capacity because of drought and siltation. However, it is estimated that the large-scale hydropower generation potential for Lesotho is approximately 450 MW. As to small scale hydro, there are currently four mini hydro-power stations in the mountains at Semonkong, Tlokoeng, Tsoelike and Mants’onyane. It is estimated that there are roughly other 20-40 sites available for exploitation with a combined potential of more than 20 MW. The situation in Lesotho is conducive to developing small hydropower systems due to adequate existing hydropower resources and a settlement pattern in rural areas that favours decentralised energy systems. The current legislation that allows independent power producers to generate electricity for the national grid and the creation of a National Rural Electrification Fund by the government is seen as facilitating the uptake of small hydropower technology.
Lesotho’s energy balance is dominated by biomass energy, which contributes 66% to the energy mix. The overwhelming reliance of rural households on biomass fuels places tremendous pressure on this forest resource. The percentage of households in Lesotho with access to energy efficient stoves in Lesotho is growing and an estimated 2900 stoves are in operation in the country, however this reliance on biomass is not sustainable. Fuelwood scarcity is already evident through the Lesotho’s reliance on imports for fuelwood and coal to complement its domestic supply. In addition, there is no institutional support for promoting alternative energy fuels such as LPG and the efficient use of biomass. Biogas is considered a difficult technology for a rural population, and the subsequent water needs for bio-digesters are difficult to meet in many rural areas. Hence, the rural population finds it much easier to burn dung directly than going through complicated digester systems to produce gas for cooking. A common problem with digesters in Lesotho is that the gas production can drop sharply in winter due to low temperatures and frost. Another major problem is a sharp decline in livestock population due to stock theft in most rural locations.