Solar Greenhouses: The Future of Food Production
Food production is a crucial element of our survival. For many years, countless scientists, researchers, agricultural experts, and others have been contemplating the future of food production. Spaces are being created for growing food, even in urban areas on rooftops and wherever food cultivation is possible.
The greenhouse itself is a structure that allows light to pass through and facilitates the cultivation of plants protected from frost and other environmental factors. Typically, greenhouses are made of glass, but there are alternatives such as so-called polytunnels, which, as the name suggests, consist of a framework covered with film. The controllable climate inside greenhouses makes it possible to cultivate a variety of plants.
Benefits of Solar Greenhouses for Agriculture
Solar greenhouses, and greenhouses in general, offer significant advantages for agriculture. Using renewable energy in agriculture allows for better cost planning and independence from the electricity market. In times of steadily rising energy prices and an increasingly unstable geopolitical situation, this is a tremendous advantage.
Greenhouses are heavily reliant on a stable power supply. If this supply is interrupted or becomes unaffordable for profitability reasons, it can pose a threat to the existence of the agricultural operation. To avoid these negative effects, energy-efficient agriculture is important. However, not only the cost aspect should be considered. Traditionally, large amounts of electricity in Germany are generated from fossil fuels such as gas and coal. Solar technology allows for a reduction in the use of these fossil fuels and a shift to environmentally friendly food production.
Technology Behind Solar-Powered Greenhouses
Solar-powered greenhouses differ from residential houses with solar roofing. While residential houses aim to cover as much area as possible with solar panels, plants in a greenhouse require sunlight. Completely covering the greenhouse roof with panels would therefore be counterproductive. Thus, crystalline modules, thin-film modules, or integrated modules are typically used on the glass roofs of greenhouses. Each type of module has its advantages and disadvantages in terms of weight, efficiency, installation options, and cost.
Let's first talk about the technology. The operation of the solar panels in a greenhouse is no different from those in a residential house. The solar cell, usually made of silicon, captures solar energy and converts it into direct current. This direct current is then passed to an inverter, which converts it into usable alternating current. This alternating current can be directly fed into the electrical circuit and used. This technology is as simple as it is robust and reliable—provided the sun shines.
How Solar Greenhouses Contribute to Sustainability
As mentioned earlier, producing one's own electricity prevents the use of fossil fuels, often used for operating conventional power plants. In certain regions, it thus becomes possible to produce safely, reliably, and sustainably all year round. Since climatic conditions in solar greenhouses are controllable, research and optimization in this area can continue to further increase food production without harming the environment. For example, solar-powered irrigation is also possible, which completely avoids the use of conventionally powered pumps and can be operated decentrally. These and many other advantages make solar greenhouses so attractive.
Case Studies: Successful Solar Greenhouse Projects Worldwide
The first example comes from local regions. The aquaponic solar greenhouse in Nauenburg am Rhein has proven to be successful. What's special about this greenhouse is that it combines fish farming with the cultivation of crops. This is a truly innovative idea. The term "aquaponics" is a made-up word formed by the builders from the terms aquaculture and hydroponics, based on these two forms of management. The facility is equipped with a solar system that covers the primary energy needs. Since 2015, it has been completely autonomous and supplies local businesses with fresh fish and plant-based foods from its own production. This project is considered groundbreaking and recommended for replication.
One of the most famous solar greenhouse facilities in the world is located in Almeria, Spain. Along with many other innovations, solar technology provides even more efficient and sustainable large-scale food production. As interesting and important as small and local solutions are for achieving constant and reliable food production to feed the global population, large production facilities are indispensable. In total, the facility covers an area of 35,000 hectares, and the annual yield amounts to 4.5 million tons of fruits and vegetables. For comparison: this is roughly equivalent to Germany's annual production. The facility is so efficient because processes and procedures are continuously optimized, and scientific findings are directly incorporated into the production process. There is a successful attempt to generate maximum yield with minimal resources.