Agrivoltaics: The future of farming?
Land use is one of the most important — and least discussed — areas of climate action. As the race towards a renewable UK grid accelerates, we look to renewable energy researcher, copywriter and blogger Robert Cathcart of Solarfast to explain how farming and solar power generation can easily share the same space.
Solar Farms have long been a bone of contention in the UK. We pride ourselves on our green and pleasant land and, over the last 300 years, traditional farming has contributed to the look of our beautiful British countryside.
But, times are a-changing, and we often forget that there is nothing natural about the way our country looks. Fens, woodland and other natural habitats have been destroyed to make way for crops to feed our ever-expanding population.
To give an example of just how much things have changed, the total amount of hedgerows removed or damaged in the last 100 years would circle the earth 6 times. That’s a lot of indigenous species that have been made homeless. One thing that could help with rewilding, food production, energy generation AND the UK’s Net Zero journey is Agrivoltaics.
What is Agrivoltaics?
In essence, agrivoltaics is the mixing of agriculture and solar power generation (photovoltaics). While we are all familiar with the concepts of solar farms, agrivoltaic farms differ in that they are designed to promote food production as well as harvesting solar power. The idea being to design an energy system to enhance, or improve, the field that it is used in.
For instance, you may want to grow shade needing crops like Brassicas, carrots and beetroot, so a system that shaded those plants from the sun a few hours a day would be ideal. Or, maybe you’re growing cereal crops, in which case you’d design something with high frames to keep the panes out of the way of the heavy machinery.
History of Agrivoltaics
Agrivoltaics is not a new concept, but it hasn’t been gaining any traction in the world of energy production until now. It was first brought to prominence by Germans Armin Zastrow and Adolf Goetzberger, the founders of the Fraunhofer Institute for Solar Energy Systems ISE, in 1981. But, wasn’t really taken seriously until Christophe Dupraz arranged performance studies in France to see if the idea was viable – and it turns out it is.
Experiments in Agrivoltaics
As most of the world has signed up to the Paris Agreement on Climate Change, America’s little wobble notwithstanding, it is no surprise France is on the forefront of experiments in Agrivoltaics. Christophe Dupraz’s research into Land Use Optimization found that the kind of crops you grow can make or break the success of your Agrivoltaic land, and some crops were actually thriving while being under panels.
The panels are important too, as these studies looked at how shading affected the crop yields and the benefits of generating a micro-climate due to the panels being above the crops. Once you understand the PAR, which is the entire visible light spectrum (400–700 nm), and how that would affect different crops and the PV efficiency of the panels, you can start to design your farm and how it will work.
Panels offer shading, but also let certain kinds of light through them that can benefit the veggies growing underneath. It was found, during these studies, that bell peppers increased their yield by up to 3 times!
Xavier Guillot, from French solar energy company TSE, is overseeing an experiment in north-eastern France to develop solar energy without hindering large-scale cereal crops.
Xavier said, ‘The aim was to be able to meet France’s needs in terms of renewable energy development, without pre-empting agricultural land.’ The panels on this farm are mounted a few meters about ground level to allow tractors and combine harvesters to work on the land unhindered.
The panels can also track the sun for maximum power conversion, be turned vertical when it rains to clean them and allow the crops to get water… plus they can turn horizontally
to protect crops from hail or harsh sunlight. If successful, a farm of this size, 2.5MW, could provide electricity for 1,350 French people for many years to come, as well as feeding them too.
In Spain, Repsol has partnered with a Basque engineering firm specialising in agrivoltaics. A pilot in Aranda de Duero utilises an active shading mode where photovoltaic panels are used in vineyards – wine being an especially important part of Spain’s economic offer. The panels will protect the vines from excess irradiation and hot temperatures – while pumping out 100% renewable and environmentally-friendly electricity. This project is managed by Solar360.
Advances in Agrivoltaics
Panels on top of greenhouse seems like such an obvious idea that we can’t believe it’s only just becoming a thing. Panels will keep in the heat, generate power and, as there is already a huge development of greenhouses sitting there, no NIMBYs complaining the landscape is being ruined.
Greenhouses use a fair amount of energy to keep temperatures constant and create the perfect microclimate, powering them from panels is a win/win situation. Whether in a greenhouse or out in the meadows, Agrivoltaic farming means less water usage as well as doubling land use – farmers could make money from crops and from selling power to utility companies.
We are already seeing the faster growing of cannabis using LSC panels and the development of autonomous solar panel powered cars to service farm laned, so the advancements in agrivoltaics are happening right now so we will soon see this type of farming as the norm rather than a quaint experiment.
Future of Agrivoltaics
To reach Net Zero the world is going to have to start weening itself off fossil fuels and joined up thinking like mixing power generation with food production seems a fantastic way to get started. In fact, the UK and Europe really need to start upping their solar game all round, the sun isn’t going anywhere for at least 4 billion years, and we can use that abundant, clean and infinite energy to improve the way we power the world.
The UK is looking at achieving a five-fold increase in solar by 2035 and, unless we embrace Agrivoltaics we are going to struggle to reach that target.Scientists are developing better ways of using AI to track weather patterns, measure and optimize crop growth under panels and even position the panels to protect crops from dangerous weather.
More on solar power and farming:
UK councils wanted for groundbreaking soil carbon capture project
Europe’s largest renewable power generator moves into Liverpool
Wind and solar growth alleviates fears of European coal resurgence
Wind and solar growth alleviates fears of European coal resurgence
Image: Mariana Proença (Top) / Oregon State University (Bottom)