Greenhouse agriculture plays a major part in our economy, livelihood, and the environment. Solar technology along with traditional farming holds numerous benefits and enables farms to become self-sustaining, increasing crop yields and reducing electricity and water consumption. It is the future, using solar technology together with traditional farming.
The many advantages of agrivoltaics are sustainability, increased food, and energy production. It adds to the rehabilitation of damaged land, improves the microclimate of the agriculture farming process and the social impact on communities. To be able to achieve this, the system must be strategically positioned and laid out, by considering the type and nature of the crops. The tilt angle of the solar module is the main concern when placing PV modules.
There are three types of greenhouse solar power setups
1. Interspersed between crops
2. Raised and tilted panels
3. Greenhouse arrangements
In a country where load shedding is prevalent, greenhouse operators have to go the extra mile to survive. Solar panels or photovoltaic system is the answer.
Solar panels that are placed over crops give shade to low-light plants. The solar module arrangement and placement will transmit partial light and will protect the crops from possible light-related damage and in turn, the plants cool the solar system when they perspire.
Placing the modules over the crops also allows the sun’s energy to be used twice; for the growth of the crops and to generate electricity, which can be used on the farm to power irrigation, agriculture equipment and refrigeration, meeting the demands of the farm. By using renewable energies farmers support their livestock’s health with the improvement of the local air quality.
Photovoltaic arrays produce much less carbon dioxide and pollutant greenhouse gas emissions than the traditional farms of power generation. The dual use in agriculture and energy production could mitigate competition for land resources, minimizing the pressure to transform open land into farms, preserving biodiversity.
The key challenges are the high expenditure requirements for installations, but the financial benefits do pay off over time. More concerning are the uncertainties due to a lack of clear policies. The need for specialized equipment and skilled workers also poses a problem.
South Africa has great potential for the implementation of agrivoltaics with its huge farming culture. The conditions in South Africa are highly suitable for the large-scale implementation with its plentiful farmland that can be reconstructed for agrivoltaics. Crops in South Africa that prefer partially shaded conditions include tomatoes, beans, lettuce, potatoes, certain grape varieties, hops, spinach, and legumes.
An example of an agrivoltaics installation in South Africa, is the SUNFarming installation in Potchefstroom harnessing the power of solar. The project began in 2016, and produced tomatoes, spinach, cauliflower and other herbs. The project is made up of three solar tunnels/greenhouses, and no soil is needed to grow vegetables and drip irrigation is used to water the crops.
The solar tunnels produce much higher yields when compared to conventional farming. In partnership with the University of Potchefstroom, the first solar training centre in South Africa was established in 2013, which provides the necessary skills for PV technology.
Agrivoltaics will be an important part of the future of agriculture and our resources will be more sustainable through its implementation. While taking shape in countries such as China and Europe, it is still in its infancy in South Africa. It might be a new term for many farmers, but it is an exciting new technology and opportunity with impressive results that will make a significant impact on the farming sector. Author: Marisan Hallett