Solar powered irrigation

Figure 1: SunCulture solar irrigation

Today I read a thought-provoking article on the development of new technology for use in East Africa that combines the use of solar energy with the application of irrigation to cropland. This is quite different to some of the irrigation techniques I have mentioned before such as motorised pumps which do not have this eco-friendly focus. The concept of solar power irrigation is interesting as, for it to be considered useful, it needs to be both technically and economically feasible and this is much harder to achieve in certain areas of Africa due to lack of finance. One of the key ways, solar energy generated from cells would be used to provide irrigation is through the pumping of water from underground stores and then pumping the water onto the crop land.

The American company mentioned in the article – SunCulture – is a company already selling this technology in Kenya for up to $2,400 and they have plans to expand into other countries in Eastern Africa. Importantly, just 4% of Kenya’s arable land is currently irrigated meaning that food production is far below maximum capacity. In previous posts, I have mentioned the costs of irrigation methods such as treadle pumps ($20 - $100) and many of these methods are unaffordable for small scale farmers so $2,400 solar power irrigation is a far out of reach for the majority of farmers across Africa. SunCulture have worked around this through a gradual repayment scheme where farmers pay in installments throughout the year and more is paid when they have the money to pay around harvest time. In addition to the solar irrigation technology, farmers are also given access to expertise from different suppliers which can help to boost yields up to four times.

This all sounds very promising but are solar energy irrigation techniques feasible on a larger scale for most farmers? With farmers in sub-Saharan Africa being located at low latitudes, the output from solar cells is likely to be much higher than other areas as solar radiation is more concentrated around the equator. Further to this, crops are typically planted in the spring and summer and this period coincides with increases in solar radiation. The depth of the well that water needs to be drawn from is important. A greater solar panel area is required to pump water from greater depths and the area also depends on the amount of water the crop being irrigated requires.

In my opinion, this method is very feasible both technically and economically. In Africa, there is sufficient solar radiation at the correct times of the year to provide enough solar power to pump water, much of the underground water stores are at relatively shallow depth and the financial barriers are overcome by companies willing to extend time to farmers to pay them back. This is all important as well as the fact that fuel to power motorised pumps is likely to increase in price in the future. Personally, I feel that this method of irrigation has a very important role to play in the future of farming in Africa.