Solar panels are incorporated in every renewable energy strategy. There are a few key flaws or design considerations for solar panels including; heat dissipation and land use. However, there is a recently untapped resource for photovoltaic installation locations.
Japan’s Solution to Energy Crisis
Japan continually experiences land shortages. After the 2011 Fukushima disaster with nuclear reactors deactivated, Japan once again grudgingly purchased fossil fuels to meet energy needs. Japan rapidly advanced on the threshold of fossil fuel consumption. Utility- scale renewable energy became the ultimate energy solution for Japan. The challenge of solar energy’s land footprint is especially relevant in a country like Japan with most suitable land occupied. Turning to a unique approach, Japan water utilities installed pontoon mounted solar arrays on reservoirs of dams.
In March 2015, Kyocera began operation of 1.7MW and 1.2 MW followed by 2.3MW floating solar panels in June. The two arrays opened in March– Nishihira pond and Higashihira Pond. The total project between the two ponds comprises 11,256, 255- watt Kyocera modules.
Kyocera corporation commissioned the fourth project of floating solar panels. The designers expect the project to become the largest waterborne solar array producing 13.7 million megawatts. The Solar array is under construction on the Yamakura Dam reservoir. Kyocera projects the undertaking will be complete FY2018 after installing approximately 51,000 Kyocera solar modules. The resulting structure will comprise 180,000 square meters. The generation capability is expected 16,170 megawatt hours (MWh) per year, or enough energy to power 4,970 households. The offsets are upwards of 8,170 tons of CO2 equivalent of 19,000 barrels of oil.
UK Enters the Floating Arena
Another island nation takes the same approach as Japan; the United Kingdom currently constructs the largest floating solar array in Europe. More than 23,000 solar panels will complete the project. Similar to Japan’s method, the site chosen is a reservoir, Walton-On-Thames. The floating pontoon will cover roughly a tenth of the reservoir, equivalent to 8 soccer fields. The reservoir is the source of a water treatment plant. This solar array allows the water utility to achieve 6.3 MW of peak power with an output of 5.8 million kilowatt hours in the first year, equivalent to powering 1,800 homes. The companies involved expect the installation to produce downward force on the price of water to customers.
There is another floating solar array in the UK. This one is located near Manchester on the Godley Reservoir in Hyde. The 45,500 square meter array will be the second largest completed or under construction floating solar array. The array is expecting to produce about 33 % of the energy used by the local water treatment plant. The floating solar panels will greatly aid the company in generating more than 35% of their energy use. The United Utilities Firm expects to further expand floating solar panel installations.
Brazil Undertakes Western Hemisphere’s Largest Floating Solar Farm
Brazil has large hydroelectric dams along the Amazon river. One such dam constructed in 1980 flooded a swath of Amazon rainforest three times larger than New York City. In spite of such environmental devastation, the dam is only capable of 50 megawatts. Currently, the country plans to float thousands of solar panels on the resulting reservoir to feed power into the national power grid. Brazil expects to power over half a million homes with the combination of the hydroelectric dam and accompanying floating photovoltaic arrays on the reservoir. The key feature rests on the complimentary nature of hydroelectric benefiting most from wet weather and solar benefiting most from dry clear weather.
Benefits of Waterborne Floating Solar Panels
Floating water panels improve on a few limitations of land based solar reservoirs. The initial and most promising detail centers on the location of the solar array specifically on water and not valuable land. These solar arrays all currently reside on reservoir, previously vacant and unused manmade lakes. An issue for manmade reservoirs arises from a disturbed ecosystem, often allowing algae to bloom uncontrolled. Floating solar arrays block the sun, passively checking algae growth. On land, the shade cast by solar arrays can wither the grass beneath, requiring shade tolerant plants which thrive under the solar array or bare dirt.
Placing solar arrays in the middle of reservoirs also limits exposure to shade from natural and built structures such as buildings and trees. Shading and capture of solar energy by the panels also limit evaporation on the reservoir. Reductions during drought conditions would lessen. Less evaporation is of great importance on reservoirs as the water ultimately finds use to generate electricity or irrigation.
The floating solar panels are able to produce more electricity per area because of their proximity to water. Water pulls heat much more efficiently than air. With greater cooling power, the solar panels can run longer before overheating. The water can also find use towards cleaning solar panels.
Floating solar panels tackle a few key issues and are an innovative solution for otherwise unused surfaces to generate power, reduce algae and evaporation.