Abstract:
Lesotho needs a feed-in tariff policy that can help accelerate integration of renewable energy in its
electricity grid. In this study a method to determine the feed-in tariff for grid connected solar
Photovoltaic (PV) systems was developed. The necessity to set different tariffs for different
locations in terms of the solar PV array yield 𝑌, and different tariffs for different installed
capacities were examined. Location specific tariffs were examined because given a particular solar
module, the array yield 𝑌 could vary with location because of different ambient temperature and
radiation, while size specific tariffs were examined because solar PV systems have different
specific costs for different system sizes. In order to determine the cost reflective feed-in tariff, the
Levelized Cost of Electricity (LCOE) was used as the objective function. With this approach the
feed-in tariff was set as the price for selling electricity that is reasonably above the unit cost of
production. A custom spreadsheet model was used to calculate the solar PV array yield 𝑌 over
Lesotho. This array yield was used to divide Lesotho into two regions, low yield regions, and high
yield regions. Representative systems were chosen and the feed-in tariff for different solar PV
installed capacities in both regions were determined. The study found that the feed-in tariff varies
with location and system size as follows;
System Category FiT ($/kWh)
Low Array Yield Region High Array Yield Region
30 kWp Roof Mount 0.1778 0.1616
500 kWp Roof Mount 0.1597 0.1451
30 kWp Ground Mount 0.1740 0.1581
500 kWp Groun Mount 0.1453 0.1321
10 000 kWp Ground Mount 0.1138 0.1034
The study recommends a feed-in tariff that is both location and size specific. The feed-in tariff
depends on duration of the tariff with shorter periods resulting in higher feed-in tariff. A 20-year
duration of the feed-in tariff is therefore recommended by this study. The method used in this study
to determine the feed-in tariff included the impact of inflation in the analysis and therefore a fixed
feed-in tariff (that is not indexed to inflation) is recommended. The energy regulator, and theministry responsible for energy policy setting can make use of this study in setting out feed-in
tariff policy.
