In modern agronomy, sustainability and efficiency are key factors for successful crop cultivation. Geothermal energy, as a renewable resource, offers an innovative solution for heating and cooling greenhouses, which can improve productivity and reduce costs.
What is Geothermal energy
Geothermal energy is the thermal energy extracted from the Earth. At depth, the temperature remains relatively constant, regardless of surface climate conditions. Geothermal systems use this heat to warm greenhouses in winter and cool them in summer, providing optimal conditions for plant growth.
Low-temperature geothermal heating for greenhouses is implemented through the required number of low-temperature closed-loop geothermal boreholes at depths of 100 to 130 meters, which are connected into a common geothermal collector, providing the power for the heat pump units.
Unlike standard greenhouse installations, in low-temperature systems the internal installation is designed with a ΔT of 5°C, providing a fluid temperature from the heat pumps of 45°C/40°C. This means that the flow rate passing through the internal installation will be four times higher than in standard systems. In turn, this creates a flow reserve that prevents the heating elements inside the greenhouse from operating at half capacity at an outdoor design temperature of -16°C — a common issue in many current greenhouses. This approach allows you to maintain a constant 24-hour temperature of 17–18°C inside the greenhouse for your crops without the need to install large buffer tanks.
With heat source parameters of 45°C/40°C from the heat pumps, a system efficiency of COP = 5.0 can be easily achieved, providing 5 kW of thermal energy for every 1 kW of electricity consumed. This will result in operational costs per unit of production that are twice as low compared to all other alternative energy sources, making your greenhouse operation highly resilient to fluctuating energy prices.
Advantages of Geothermal Energy for Greenhouses
· Energy Efficiency: Geothermal systems offer significant energy efficiency, reducing heating and cooling costs by up to 70% compared to traditional systems. This is especially important for greenhouses, which often have high energy demands.
· Low Environmental Impact: The use of geothermal energy reduces dependence on fossil fuels and greenhouse gas emissions. This is an important aspect of sustainable agriculture, aiming to minimize the negative impact on the environment.
· Stable Growth Conditions:Geothermal energy provides stable temperatures in greenhouses, which is essential for optimal plant growth. Consistent temperature and humidity help increase yields and improve the quality of the produce.
· Low Maintenance: Geothermal systems require less maintenance compared to traditional heating systems. This is especially important for farmers who want to minimize service costs and focus on production.
· Long-Term Investment: Although the initial costs of installing geothermal systems can be high, the long-term savings on energy expenses and increased productivity make the investment highly worthwhile.
Examples of Applications
Many greenhouses around the world already successfully use geothermal energy. For example, in the Netherlands, where climate conditions can be challenging, geothermal systems have been integrated into the greenhouse industry, providing the necessary heat for growing vegetables and flowers. In the United States, especially in areas with active geothermal activity, farmers are also beginning to implement these technologies.
Geothermal energy represents an innovative and sustainable solution for heating and cooling greenhouses. With its numerous advantages—including energy efficiency, low environmental impact, and stable growth conditions—geothermal systems can play a key role in the future of agriculture. Investing in geothermal energy will not only improve greenhouse productivity but also contribute to the sustainable development of the agricultural sector.
