Yash
Climate change is a real issue, and the burning of fossil fuels is one of the major causes.
One alternative to mitigating climate change is using renewable energy sources; solar photovoltaics is one solution.
In this technology, solar panels use sunlight to produce electricity.
In this energy conversion, no harmful gases are released into the atmosphere.
This technology can be installed almost on all terrains.
But what if where the land is scarce and the place is surrounded by water like an island or a peninsula?
What is Floating Solar Technology?
Here comes the derivative of Photovoltaics which is called Floatovoltaics (Solar that floats).
However, the basic function remains the same, producing current from sunlight.
But now the solar panels do this by floating on water instead of mounted on the ground.
The solar panels are mounted on the floating structure (usually of plastic buoys and cables).
This technology is gaining popularity in countries where land is more valuable for crop growth. However, water bodies such as lakes, ponds, and reservoirs near these lands can be ideal sites for floating solar panels.
History
The credit goes to Japan for the first floating solar installation. The National Institute of Advanced Industrial Science and Technology completed this installation in 2007 in Aichi (Japan).
Installation
Mooring is a process of securing an object boat or vessel in a fixed position using anchors.
The type of mooring depends on the bed soil. If the soil is intact then the anchors are penetrated using screws to make the solar panels stable on the ground. If the soil is contaminated or loose then anchors cannot be penetrated effectively. In that case, the weighted ballasts are used to secure the position of the object.
It required certified boat captains and divers for drilling and anchoring the project.
Water is a liquid state and land is a solid state.
Therefore, the installation on water is technically different than on land.
The mooring must have some level of elasticity in it to withstand the water movement and keep the system stable.
Also, the change in the temperature affects the water level. It goes down in summer due to evaporation and rises during monsoon due to rainfall.
Therefore, the mooring should ability or an arrangement to keep the floating solar stable and intact.
Advantages of Floating solar
a) It does not occupy land
One of the biggest benefits is that it does not occupy land and provides you with solar electricity. This technology is popular in places where land is more valuable for crop production and irrigation can be done with floating solar installed on the reservoir near the land.
b) Helps in water conservation and maintains the water quality
Installing floating solar on water reservoirs can be dual benefits for the sites which are very hot and there exist perpetual drought conditions throughout the year.
First, the solar panels act as a shade for these water bodies and prevent the evaporation of water.
Second, the shade prevents the growth of algae which deteriorates the water quality by depleting the oxygen dissolved in water. Also, the algae growth releases harmful toxins into water making it unfit for consumption.
c) Increased Efficiency due to Cooling
Sunlight falling on solar panels’ surfaces has a heating effect too. This increases the cell temperature. And it is a known fact that solar panel’s output deteriorates with increasing temperature. However, the water underneath the solar panels keeps them cool.
Read: Best solar panels for hot climate
This cooling effect reduces the cell’s temperature and hence increases the energy conversion efficiency.
The efficiency of a solar panel degrades with every degree rise in the silicon cell temperature beyond 25° C. The extent of the reduction in efficiency can be determined by the metrics called the temperature coefficient of power mentioned on its nameplate.
d) Effective sunlight tracking
The solar panels are floating on the structure, unlike on land, where they are fixed. Therefore, it is much easier to rotate them vertically and horizontally where the sunlight is maximum with less complex tracking systems, and hence, they can receive the maximum sunlight.
Disadvantages of Floating Solar
a) Corrosion
The base of the solar panels is water and they have to operate on water throughout their useful lives. The saltwater is very corrosive. Therefore, the solar power system has to be enhanced corrosion resistant. This increases the maintenance cost of the system.
b) High tide waves
The solar panels have to withstand wave pressure and relatively high wind pressure than the solar panels installed on the land.
c) Anchoring Technology
The anchoring makes floating solar stable on water. However, high waves, wind speeds, and storms can displace the solar panels from their optimum positions, hence affecting solar electricity production. Therefore, the anchoring technology has to be developed keeping all the abnormalities in mind.
d) Ecological balance
- Although the shading of the water bodies through floating solar may inhibit the growth of harmful algae.
But it has a harmful impact also. The shade of solar panels prevent the sunlight from reaching the water. This inhibits the process of photosynthesis by zooplankton hence disturbing the ecological balance.
Also, some people believe that floating solar affects the natural beauty and obstructs the recreational activity on the lake.
Potential of Floating Solar
This technology has a huge potential. The reservoirs can support enough floating solar panels to power millions of houses. However, we need to address the impact on aquatic life with the growth of floating solar.
Also, we need to identify the water sources that are ideal for floating solar and have minimal impact on aquatic life.
An integrated system (combination of floating solar and hydro-power plants) could be proposed by choosing a reservoir that is close to the hydropower plant.
When the water level reduces during drought, the hydropower plant efficiency deteriorates.
In that case, the floating solar can provide electricity while the hydropower system can wait for its turn until the water level rises again.
