A solar farm in Hemau, Germany. Photo: Frank Stremke
There is no denying that we need to transition to a low-carbon future. That means more solar power and wind energy. But how can we achieve that in the Netherlands, which is so densely populated? And how can we ensure backing among local residents for wind turbines or solar farms? These are issues WIMEK researcher Sven Stremke has been considering for years.
WUR associate professor of Landscape Architecture Sven Stremke specializes in energy landscapes: environmental settings in which energy is generated. He and his team have concentrated on solar farms in his most recent research at the Wageningen Institute for Environmental and Climate Research (WIMEK); while wind energy is still important, its acceptance among local communities is declining so many regional authorities now prefer to focus on solar farms.
At present, the solar parks are mainly built on farmland and are geared to maximizing the energy generated. That is a missed opportunity in Stremke’s opinion, as so much more can be done with them. “In our study, we investigated 11 European solar farms that serve other purposes as well as generating energy. We looked primarily at visibility and use of the land. Visibility is a key factor in the acceptance by local residents. Not many people will worry about solar panels alongside a motorway but it is a different story if people come across them in an area that is popular for walks. Land use is about multifunctionality: can you use land covered in solar panels for other purposes too, such as agriculture?”
Multifunctional land use
According to Stremke, it is quite possible to use solar farms for multiple functions. More and more sites across Europe are combining agriculture and solar energy, what is termed ‘agrovoltaic energy’, for example by installing panels very high up to allow farming underneath them. Stremke: “In the Netherlands, market gardeners grow pears, redcurrants or raspberries in solar farms. The solar panels they use are more translucent than ordinary panels so the plants still get enough light.”
Not many people worry about solar panels alongside a motorway but it is a different story when a solar farm is put up in an area that is popular for walks
Nature-inclusive solar farms can boost biodiversity. Photo: Shutterstock
The microclimate under the panels can be good for the plants — cooler in the summer and warmer in the winter — with a positive effect on the harvest. The panels also protect the crops from rain and hailstones, which reduces the risk of fungal rot and hail damage. Nature-inclusive solar farms are another example of multifunctional land use. Stremke: “You can use them to enhance biodiversity, for example. If you take a field in an area with intensive arable farming out for production for 25 years, that gives the soil a chance to recover because you aren’t removing organic mass or adding fertilizer.” Surrounding the solar farm with hedges and verges full of flowers also increases biodiversity. What is more, that makes the solar farm less visible, which can reduce local people’s resistance to the farm.
Visibility and resistance
Municipalities and landowners need to think hard about their choices when constructing solar farms, says Stremke. The One Wageningen Solar Research Programme, of which he was one of the initiators, can help them with this. The programme aims to provide a scientific basis for developing sustainable solar farms that benefit the economy, nature and society at large. “There are lots of decisions to be made when building a solar farm: do you just want to generate energy or also contribute to agriculture and biodiversity? Do you want to do something for local residents, for example by combining the solar farm with recreational or educational facilities? In this programme, in which we collaborate with public authorities, landowners and energy suppliers, we see that such decisions are often made right at the start of the project and they are also often implicit. The landowner and developer approach the municipality with their design, and local residents only see it much later when they can’t really have a say anymore. Whereas getting residents involved earlier is an effective way of preventing resistance.”
Agrovoltaic energy is used in Babberich and Tiel. These solar panels are translucent, so plants will get sufficient daylight. Photo: Sven Stremke
Solar panels offer proper protection for sheep and chickens, as seen in Hemau. Photo: Dirk Oudes
In addition to giving people a say, participation is a key method for generating public backing for a new solar farm. Stremke: “If you can invest personally in the solar farm as a local resident, rather than some unknown investor company, you feel much more engaged with the project.” A town can also welcome this opportunity to help the energy transition if the solar farm simultaneously offers a solution for long-standing local problems — a rubbish dump, an area where the soil is exhausted due to intensive agriculture, or a plot designated for a business park that was never built.
Keep policymakers alert
According to Stremke, WUR has an important role in keeping policymakers alert. “We can show policymakers that a particular option they have in mind didn’t work out well in other countries, for example. Or we can tell them what does work well. In Germany, the grant system for renewable energy is updated annually to take account of new scientific insights. For example, at one point there were concerns about competition between agriculture and energy generation. So the German government reduced the grant for solar panels on farmland and raised it for solar panels on poor-quality, inaccessible land, making it more attractive for developers to build their solar farms there.”
There are many decisions to be made when building a solar farm: do you just want to generate energy or also help agriculture and biodiversity?
Fortunately, the Netherlands is also starting to change its approach to grants for sustainable energy, says Stremke. At first, the focus was exclusively on the cheapest option — and putting up solar panels in an empty field happens to be cheap and easy. But now that we are running out of such plots for low-cost, large-scale solar farms, Stremke argues that fitting the solar farms into the landscape is the only way to achieve the required energy transition. The new Dutch government seems to realize this: the coalition agreement mentions multifunctional solar farms.
More research needed
While the research has resulted in a much better understanding of specific aspects such as land use and visibility, more studies are needed, for example on maintenance and circularity in material use. Stremke wants to combine this research with actual practice. “We’re currently carrying out several ‘action-research’ projects in which we develop the solar farms of the future. That will let us focus more on a third aspect of our research, namely the temporary nature of these farms and, consequently, circularity. If a solar farm is taken down after 20 years, the land can be reused for other purposes. So it is important to make sure everything is degradable or can be recycled where possible.”
Involving residents early on when building a solar farm prevents resistance. Photo: Sven Stremke
Stremke and his colleagues also want to experiment more with the maintenance of solar farms. The vegetation needs to be kept under control, for example by mowing. But the cuttings then need to be removed “Because indigenous plants, which are important for insects, need poor soil. If you leave the cuttings where they are — which is what mostly happens as it is cheaper — they turn into compost and that enriches the soil. All these aspects make action research on solar farms an interesting option for WUR because there are so many connections with our own research topics.”
Resolving the energy issue
What does the future hold for energy landscapes according to Stremke? “By 2030, by which time most of our energy will need to come from renewable sources, I hope wind turbines and solar farms will be accepted elements in the environment — the right technology in the right place — and part of our daily lives. At present, we have outsourced a lot of our energy generation to other countries, so we are not aware of what is required to satisfy our demand for energy. Research shows that people are more prepared to save energy when they see how energy is generated. Anyway, we can’t rely on other countries to resolve our energy issue. Not a single country will have a surplus of renewable energy in the period through to 2050. The only solution is to become as self-sufficient as possible and that means we need solar farms badly.”
Read more about the One Wageningen Solar Research Programme on the Wageningen University & Research website.
Read more about the research of the Wageningen Institute for Environment and Climate Research (WIMEK)
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