For renewables to fully integrate into the world economy, experts say green energy production plants are crucial. Yet some critics argue that we should be wary, with claims that major renewable production sites could harm the environment, for example by disrupting ecosystems. Others argue that they are aesthetically unpleasant or that they use an excessive amount of land that would be better allocated for farming food for the world’s growing population.
But a new wave of innovators and lateral thinkers are coming up with ways to make big renewable energy production sites not just less harmful for the environment — but actively beneficial. By developing a more holistic approach to green energy productions, they are designing a new generation of plants that can unlock synergies between solar, wind and other forms of power and nature, so that energy production can benefit both humans and the environment. From aquaculture farms to solar greenhouses, here is a round-up of the latest innovations in the field.
In the North Sea, a Dutch-Belgium consortium has created the “Wier and Wind” project, which pioneers the doubling down of offshore wind turbines as seaweed farms (“Wier” is the Dutch for “seaweed”):
- Smaller seaweed farming projects near offshore wind farms have been run in the past, but the Wier and Wind project will be one of the first large-scale pilot projects. It covers up to 20,000 square meters some 20 kilometers off the coast of Zeebruges, Belgium, where about 44 wind turbines generate about 370MW for the Belgian grid.
- With the project, which started in July 2019 and will run until June 2022, the plant will now also produce some 15 tons of seaweed per year. Seaweed farms — which use long underwater cords — have been set up between turbines, separated by a buffer zone.
- Today, seaweed is generally sold on Asian markets, where it ends up on dinner tables. But more and more innovators are turning to it for its potential in the green economy too. For starters, seaweed is a powerful carbon sink that can be used to manufacture bioplastics and biofuels. But it can also serve as a greener ingredient for animal feedstock that doesn’t require arable land to be farmed.
- The partnership between energy companies and farmers entails combining site visits, purchase efforts, and maintenance.
- In December 2020, North Sea Farmers, one of the partners of the Wier and Wind consortium, announced it would try to replicate the project in offshore solar farms.
Outside of private roofs, some of us are used to seeing solar panels as part of sprawling ground-level solar farms. But who said that’s the best location for them? French renewable energy company Tenergie has been operating a solar greenhouse since April 2017 in the Bouches-du-Rhône region of southern France.
- Fitted with 265-watt panels on its roof and with an installed power of 2.1 MW, the greenhouse can generate enough electricity to offset its energy demand and satisfy the energy needs of some 700 households. At the same time, it produces fresh asparagus and a variety of other vegetables.
- The idea is akin to placing solar panels on roofs rather than in the middle of a garden: it maximizes the yields of land already altered by human activity rather than taking up more space.
- The solar panels used in such greenhouses are not the traditional silicon-based type — they are semi-transparent organic solar cells. They provide extra flexibility, let in more light and cast less shadow on the ground than their counterparts. Usually, such greenhouses are also equipped with light polycarbonate diffuser and roof opening systems to improve temperature control, light diffusion and ventilation.
- Ok, but is the food any good? It seems so. A study by North Carolina State University said that semi-transparent solar cells don't affect the growth and health of the plants in the greenhouse. The study was run on lettuce and found no notable difference in any key measurement, including antioxidants, CO2 absorption, weight and size.
- Researchers plan to test the effects of these solar greenhouses on tomatoes next.
- Tenergie has a project to build around 30 such greenhouses over the next three years.
- The dream is to use these solar panels on the windows of urban buildings one day, though that is unlikely to happen very soon.
A recent study has shown that installing a high quantity of solar panels along Californian canals could save the US state hundreds of billions of liters of water — while also generating a sizeable amount of energy:
- California's north is rich in water, but up to 80% of the state’s water demand comes from its dry south. To solve that, California has built a vast network of canals bringing water where it needs the most. But when the water is exposed to the scorching summer sun, a lot of it evaporates.
- The study, published by Nature Sustainability, said that fitting canals with a vast solar panel network would solve two problems at once. On the one hand, the shade cast by the panels would help cool the water and prevent evaporation, saving up to 63 billion gallons (283 billion liters) of precious water per year; on the other, it could generate 13 gigawatts of green energy.
- Another positive effect is that this project would save land otherwise used for solar plants.
