While there are energy solutions for solar agricultural pumps, research has revealed that nine out of ten African families depend on agriculture for their livelihoods and only two among these utilize irrigation, as the rest rely on the increasingly unreliable rainfall.
On the other hand, switching to irrigated agriculture has been proven to increase yields by up to 90%. This is in comparison with farms that rely on rainfall.
However, high diesel costs continue to make irrigation an unaffordable expense for many smallholder farmers. Unfortunately a very small number of Africans have access to the main grid. As such, electric water pumps ceases to be a viable option for the 620 million Africans without connection.
Solar energy is one of the easiest ways for farmers to produce energy. Furthermore, the use of solar energy in agriculture is becoming increasingly popular in Africa. What’s more, the energy produce could very well be used to provide the farmers with additional income. Arid regions in Africa are some of the places where irrigation is used. As such, these areas count as the biggest beneficiaries of solar energy.
On the other hand, irrigation requires energy. Currently, diesel and electric pumps stand as the dominant technology offerings. Similarly, grid-connected pumps that rely on electricity are also plagued with the challenge of outages.
The farmers thus end up losing what could otherwise be disposable income. Nonetheless, solar pumps also don’t come cheap. A one horsepower solar pump goes for approximately US $3,000. This makes it unaffordable for most small, marginal rural farmers with a couple of acres or less.
Making it work
Starting with the pump, the amount of solar power needed depends on the specific water table depth of a farm. That is, the further the water is from the ground, the more power would be needed to pump that water up for irrigation. This, in turn, is highly dependent on the geography of a particular region.
On the other hand, since water for irrigation is only needed during certain hours of the day, using the solar pump could be a way to better utilize the solar panels. Furthermore, the solar panels for a solar pump could also be viewed as assets that generate electricity to be used by people in their homes.
The pumps used for the transport of the water have solar cells. These then absorb solar energy and converts it into electrical energy. This is done through generator which then feeds an electric motor driving the pump. Most of the traditional pump systems mainly work with a diesel engine or with the local power grid. However, these two modes of operations present disadvantages compared to solar pumps.
Diesel pumps are slightly more efficient than AC powered pumps as they allow greater flexibility. However, one of the main constraints is that this system relies on the fuel availability.
Moreover, inasmuch as diesel-driven pumps may be cheaper than solar-powered pumps, operating costs are quite high and are heavily dependent on the diesel price. Conversely, the solar-powered systems is relatively expensive. However, the source of energy is free; since after there are no operating costs after the pay off period. This makes the latter a worthwhile long-term investment.
Access to water for agricultural purposes remains critical in some areas such as in arid regions of Africa. Many African farmers fetch the water directly from the well or the rivers and irrigate their fields using buckets. As such, access to a motorized pump could very well their yield tremendously.