- Differences between projected and actual solar production could reduce solar savings for C&I consumers.
- Urban solar systems often underproduce solar power by as much as 5%.
- Installations outside urban centres see more forecast bias, up to 20 per cent.
According to a recent report by CrossBoundary Energy, biases in the data used to estimate solar production on the continent can lead to a lower savings reduction for businesses and a 1-2 per cent reduction in the internal rate of return (IRR) for developers and investors. The report notes that electricity tariff and resulting savings are factors often given priority consideration during development. In contrast, the on-sit estimated solar irradiation, which can significantly impact forecasted production and expected savings, is often overlooked.
The report titled ‘Measuring Solar Irradiation in Africa’ analyses two operational sites, in Nairobi, Kenya and Accra, Ghana, and indicates that the actual measured solar irradiation deviated from the widely accepted satellite data (used to predict production during solar system design) by as much as 3-5 per cent. The report also notes that in sites outside of major cities, the bias is even higher (up to 20 per cent) as satellite solar irradiation estimates do not factor in the variable microclimates created by diverse topography,
The report states that these biases could lead to underperforming systems compared to their forecasted estimates. For example, C&I customers in cities could see a 4 to 5 per cent drop in their projected solar savings, while those outside cities could see drops of up to 20 per cent. As a result, investors could see a reduction of p to 1 per cent in projected IRR for urban sites and over 1 per cent for diversified rural and urban installations.