Floating solar power plants!

Intro

One of the major drawback of a solar panel is that it is unable to convert more than one quarter of the incident energy (solar radiation) into electricity. The most efficient commercial solar panel has a conversion efficiency of about 22%. Thus, it is only feasible to install these panels in large numbers, to reap any kind of return-on-investment.

The key factor to be considered while designing large scale solar power plants, is the effective use of the available space. This can be associated with the large sum of money that the organizations have to spend on buying or leasing the land. So any concept for smarter land use is always welcomed.

One such idea for the smart use of space: Floating solar power plants, is being implemented in Japan. The very idea of generating electricity on top of water sounds absurd, but it works as advertised!

Setup

The power plant consists of an array of solar panels connected together- about 50,000 of them; to produce about 13 megawatts of electricity to power 5000 households. Five thousand households may seem as a small figure, but in a power-hungry country like Japan, this equals an offset of around 7,411 tonnes of CO2 emissions every year that it’s in operation. (equivalent to 19,000 barrels of oil).

Even the material used to fabricate the floating fixture, on which the panel is mounted, is innovative. It is a non-metallic and high-density polyethylene material, that is resistant to both corrosion and the sun’s ultraviolet rays. It is also claimed that the floating structure is non-toxic and does not affect the quality of the water in any way.

Pros

• The water body, being open and wide, ensures zero loss in power output due to shadow cover.
• The lack of a solar tracking system, further reduces the cost of the overall setup. This can be used to mitigate the extra money spent on the special structure.
• Another added advantage of floating PV panels is that, it is naturally cooled by the constant winds and the evaporation of water.

• The manufacturer of the floating fixture claims that their structure is strong enough to withstand storms and even typhoons, which is quite common in Japan. (By strong they mean that the panels will remain intact)
• Finally, these panels require just minimal maintenance. There is no need for weekly cleaning of the panels, since there are no trees for leaves to fall off from and almost zero chance of dust covering the panels.

Cons

Despite the smart use of space combined with clean electricity, this project has some limitations.

• Since the PV panels cover the water body, the evaporation rate is affected. This in-turn can possibly affect wind patterns and cause untimely monsoon showers. Or even worse, it can cause considerable time gaps in between consecutive monsoons.
• I am no expert, but I think that the floating fixtures affect the aquatic ecosystem as a whole. Although the structure is non-toxic, it does prevent sunlight from entering the surface of the water. It causes a shadow effect which can affect the lives of aquatic creatures and plants.
• Furthermore, the growth of algae is also hindered by installing the panels on top of the water surface. This is a deal breaker because, everything from bio fuels to medicinal capsules are produced from algae, the market for such products is on the rise.

• Lastly, the solar panels are fixed. That is, they cannot be tilted to always face the sun. This prevents the system from generating extra or maximum electricity.

Conclusion

This concept is innovative because, about 70% of the earth’s surface is covered with water!

So it is only logical to use it to generate cleaner electricity. I think that the manufacturer has tackled most of the possible drawbacks despite a critical few. Therefore, personally, I think that this is a concept that should be encouraged and further developed upon. The plant is said to be finished by 2018 and I am among the many whom are eager to observe the outcome of this project!