Floatovoltaics: The Future of Renewable Energy?

Floatovoltaics is a relatively new, but rapidly growing industry where solar panels are floated on water reservoirs. It stems from the desire to decarbonise global economies by 2050 as a solution to tackling climate change.

WhenSolar panels are placed on water, it keeps them cool, which makes them around 5 percent more efficient than land-based ones. Additionally, multiple panel arrays shield the surface from the sun, potentially reducing evaporation, which in turn provides more water for hydropower and irrigation.

“Hydropower reservoirs are already designed for distributing electricity to where it is needed, so if paired with solar energy, the infrastructure is already in place, helping to reduce costs. The power generated could also potentially be stored in reservoirs when sunlight is high to use later when sunlight is weak,” according to a report by azocleantech.com.

Aside from the pressure of finding enough space for solar panels, the Nature journal, however, identifies that there are a number of unknowns associated with social, technical and economic environmental impacts of this system.

Hydropower plants can be carbon-intensive, with high emissions while Methane can be released from decaying submerged plant matter, even emitting as much carbon as fossil-fuel plants.

Therefore, research is needed to fill gaps in knowledge, preferably prior to the major roll-out of this technology, which has the potential for unforeseen complications.

Obstacles to increasing Floatovoltaic production

Floatovoltaics are currently marginally more expensive than land-based ones, but the market is rapidly expanding, with lots of projects underway. One in Batam, Indonesia, aims to produce 2.2 GW through solar panels over 16 km2 of water, which will double global floatovoltaic production.

Public opposition to floatovoltaics could increase if potential issues are not researched thoroughly beforehand, which, in turn, will put private investors off and potentially harm the switch to decarbonizing economies. 

The environmental impacts must be assessed carefully before embarking on massive photovoltaic installations. Climate change is increasing water temperature in seas, rivers and lakes, which in turn creates harmful algae blooms.

Scientists have modelled whether covering water in solar panels has a beneficial effect in reducing algae blooms and discovered they can, but a lot more research is needed. Physical, chemical and biological reactions, wildlife, water ecosystems and drinking water can all potentially be affected.

Organisms that rely on photosynthesis to survive, such as plants and phytoplankton may be affected. Reduced sunlight helps restrict algae blooms from increasing, but reduced oxygen could have a detrimental effect on fish.

Other considerations

Floatovoltaic projects could also potentially interfere with livelihoods such as fisheries, and impact people that are heavily reliant on fish for consumption and export.

Moreover, there are also technical issues to address. Bird feces and microbial biofilms are likely to be more of a problem over water than land and reduce photovoltaic output.

The formation of ice and the cost of breaking it is likely to increase operational and maintenance costs, as has happened in Heilongjiang province in China.

Tropical cyclones and high winds could cause damage. In Japan, panels piled up and a fire broke out on the Yamakura Dam.

Drought can reduce water levels of water reservoirs, and the need for drinking water and agriculture is likely to outweigh the necessity for stable water levels for floatovoltaics. Therefore, engineering solutions and cost evaluations are required.

Transparency is likely to boost investor confidence, but researchers need to model costs given the variability across different sites, and also publish outcomes for scrutiny when large projects go live.

Science and decision-makers need to work together to ensure that as and when floatovoltaic projects are developed throughout the world, they are both equitable and sustainable.