Harnessing sunlight is a crucial factor in the advancement of renewable energy. The growth and reduced costs of photovoltaic panel manufacturing have facilitated the proliferation of solar power plants worldwide, especially in countries where land is a scarce or expensive resource. In these cases, creativity has led to innovative solutions such as installing solar panels on water , freeing up land for other uses like agriculture or construction. These floating solar power plants have become a trend in several countries with promising results.
Advantages of solar panels on water
Floating solar installations offer a number of advantages over traditional land-based plants, which has motivated their expansion in countries with geographical limitations, such as Japan, South Korea and the United States. Among the main benefits are:
- Space optimization: Placing solar panels on water surfaces frees up land for other uses, which is especially useful in densely populated areas or areas with valuable agricultural land.
- Less visual impact: By installing panels in reservoirs or lakes, the visual impact that solar plants usually generate on large tracts of land is avoided.
- Extending the life of the panels: The water beneath the panels provides a natural cooling effect, reducing overheating of the modules and improving their performance compared to terrestrial installations.
- Maintaining water quality: The shadows generated by the floating panels on the water surface help reduce algae growth and decrease the evaporation rate, which can be beneficial in areas at risk of drought.
Japan and South Korea: pioneers in floating solar energy
Japan has been one of the first countries to invest heavily in floating solar technology. In a country with limited land resources, solar projects on reservoirs have made it possible to take advantage of underused areas. A clear example is the Yamakura floating solar plant, where 51.000 solar panels have been installed on a reservoir. Thanks to this plant, enough electricity is generated to supply 5.000 Japanese homes.
South Korea has also been a leader in this type of installation. In 2014, the floating solar panels built on the OTAE and Jipyong reservoirs became a benchmark, with a capacity of 3 MW each. These solar plants cover more than 64.000 square meters and can provide energy to an average of 2.400 homes, in addition to reducing algae growth and water evaporation.
Spain and floating solar photovoltaic energy
In Spain, the adoption of this technology is also gaining momentum. The pioneering project at the Sierra Brava reservoir in Extremadura was one of the first floating solar installations connected to the country's electricity grid. This project is designed to test the effectiveness of different types of solar panels and flotation systems under real-life conditions. One of the most notable innovations is the installation of bifacial modules, which allow solar energy to be captured both from their main surface and from the back, optimising their performance.
It is also significant that tests are being carried out on the environmental impact of these systems on water, since both the reduction in evaporation and the shade they cast can have beneficial effects on the conservation of water resources.
New trends and expanding megaprojects
Globally, floating solar energy is growing exponentially. Countries such as China, Brazil and India are leading the expansion of these solar parks in aquatic areas. According to World Bank estimates, if 10% of the world's artificial reservoirs were used for floating solar projects, approximately 6% of the world's electricity consumption could be generated.
On the other hand, the cooling effect of water improves energy efficiency, increasing production by 10% to 15% compared to conventional installations. In Egypt, for example, it is estimated that covering 250 square kilometers of water surface would generate 66 TWh of electricity annually, in addition to saving more than 200 billion gallons of water per year.
This technology is not only being implemented in lakes and reservoirs. In the United States, research such as that carried out in California is exploring the possibility of installing floating solar panels in irrigation canals, which would save large quantities of water that would otherwise evaporate.
Environmental impacts and challenges
Despite the many advantages offered by floating solar plants, it is also important to consider the potential environmental impacts and technical challenges. Among these, the impact on aquatic ecosystems is one of the most studied. Although the shade of the panels can limit algae growth, some experts point out that excessive coverage of the water could alter underwater ecosystems. Plants and animals that depend on sunlight could be affected, especially in reservoirs with low water levels.
Strict regulations are therefore being developed in some countries to ensure that installations are implemented in a sustainable manner. In Spain, for example, the recent regulatory framework establishes that floating solar panels may only occupy between 5% and 15% of the surface area of ​​reservoirs.
Additionally, the logistics and initial costs for installing these floating systems are considerably higher than conventional solar plants, mainly due to the difficulties in anchoring the structures and managing the transport of the floats and panels.
However, the advantages in terms of water savings, reduced visual impact and greater energy efficiency make floating solar panels a solid and promising alternative for generating clean energy worldwide.
Floating solar energy is not only a technological innovation, but also a strategic opportunity to optimize the use of water resources, reduce the need for land and contribute to the fight against climate change.