Many farmers in remote areas of Australia have long relied on self-sufficiency due to the high cost of connecting to the electricity grid. However, as the cost of solar energy falls, more and more farmers are seeking self-sufficient electricity production. However, intermittent solar radiation poses a major challenge, as farms without storage or backup power still rely on the power grid when the sun is not shining.
One solution that is gaining increasing acceptance among farmers is the use of pumped microhydropower. It involves connecting one or more dams together to create a small pumped hydroelectric power plant that can store electricity generated from solar energy during the day and use it at night. This option allows farmers another form of self-sufficiency by using the water in their dams as energy storage.
Research has identified more than 30,000 rural sites where micro-hydropower could be deployed, with the potential to produce two kilowatts of energy and store 30 kilowatt-hours of energy. This would be enough to power a typical home in South Australia for 40 hours.
Pumped hydroelectric power plants essentially work with two reservoirs, one of which is higher than the other. Excess solar energy is used to pump water from the lower reservoir to the upper one, effectively storing the energy. When electricity is needed, water is returned to the lower basin, where it drives a turbine and generates electricity.
While large hydroelectric power plants are already established, small systems are not yet economically viable. However, the falling cost of solar energy has changed the economics as larger solar installations have become more cost-effective and opened up opportunities for storing excess energy.
Compared to commercial lithium-ion batteries like the Tesla Powerwall, micro-hydropower storage is 30% cheaper for locally generated solar power needed at night, such as to power irrigation systems 24 hours a day.
The implementation of microhydropower systems depends on the size of the existing dams on the farm, the rivers, and the topography of the country. The efficiency of the system depends on the gradient between bodies of water and is therefore best suited to areas with a significant difference in elevation of at least 20 meters.
Overall, microhydropower represents a promising solution to the solar intermittency problem faced by farmers in remote areas. With the potential for cost savings and greater self-management of energy production, this technology could have a significant impact on agricultural communities.
