Writer: H M Remi

Electricity and water usually don’t get along well with each other. However, there is a growing number of floating solar farms developed worldwide. Why is that?

One of the reasons is because solar panel installations take up land space. While land space is limited, water surface is a good choice for building the systems.

Floating solar farms have the advantage of cooling down water temperature and reserve water resources. The Earth only possesses 1% of freshwater bodies on its surface, providing drinking water and crop irrigation for billions of people. Yet, the water surface temperature has been increasing by an average of 0.34°C per decade since 1985 due to climate change. Rising water surface temperature not only lowers the oxygen level of the waters, affecting the ecology underneath, it also causes toxic algal blooms that lead to water pollution. Water also evaporates under high temperature, in turn affecting the supply of fresh water.

Fortunately, in addition to mitigating global warming, floating solar farms could also bring down the water temperature and reduce water evaporation, thus reserving precious freshwater.

How does the system work to achieve all these?

By customizing the floating solar panel layout for different lakes or reservoirs, wind speed and solar radiation across the entire lake or reservoir could be reduced by 10%. This is the most efficient cooling effect that helps to change many of the ecological processes that happen within, capable of offsetting around a decade of warming from climate change. Acting as shelters, floating solar panels could also reduce water evaporation.

Recent studies also show that floating solar systems could generate more electricity than rooftops or ground-mounted solar systems do, thanks to their cooling effect. By cooling down the water temperature, they could boost the electricity generation by 12.5%!

If we cover just 1% of the surface of all human-made water bodies across 35 countries with floating solar panels, we can generate 400 gigawatts of electricity, which could power up 44 billion LED light bulbs for a year!

So far in Hong Kong, we have implemented two small-scale pilot projects of floating solar farms at Shek Pik Reservoir and Plover Cover Reservoir. The amount of electricity generated is equivalent to the annual electricity consumption of 36 average households with a reduction of 84 tonnes of CO2 emission.

CarbonCare InnoLab, under the Jockey Club SolarCare Programme, organises SolarVisits to the floating solar farms in Hong Kong. We hope that the Hong Kong Government could build more floating farms in the city in order to meet the target of achieving carbon neutrality in Hong Kong by 2050.

If you are interested in the SolarVisits, please keep an eye on our Facebook page for future event releases.

Reference:
https://theconversation.com/floating-solar-farms-could-cool-down-lakes-threatened-by-climate-change-157987
https://www.wsd.gov.hk/en/home/climate-change/mitigating/floating-solar-power-system/index.html
https://www.ccinnolab.org/solarcare/en/SolarVisitPost/SolarVisit
https://www.thenewslens.com/article/128319

Image source:
https://theconversation.com/floating-solar-farms-could-cool-down-lakes-threatened-by-climate-change-157987