Floating Photovoltaics: A Promising Solution in the Fight Against Climate Change?

Floating Solar Panels being installed in Walden, Colorado Source: Dennis Schroeder/NREL

Solar energy has come a long way in the global transition towards a more sustainable energy landscape. Over the years, this renewable energy source has evolved from a niche technology to a central player in the global shift toward cleaner energy sources. Solar energy, while a powerful and sustainable source of power, is not without its challenges. One of the primary concerns associated with solar power is the substantial amount of land space it requires for large-scale installations.

Land-scarce nations like Singapore and Korea can’t afford to allocate large swathes of land for solar farm installations. This is not a trivial challenge as land is also needed for food production and biodiversity conservation.

In the quest to satisfy our energy appetite and combat the challenge of climate change, this technology stands out on the horizon. It’s an emerging solution that is gaining rapid momentum. It’s called “floating photovoltaics” or “floatovoltaics”. It’s a simple concept where you install solar panels on reservoirs/lakes/ponds. You basically let them float on the reservoir on specifically designed frames and are connected to the grid to generate electricity.

As of now, floatovoltaics remain a niche technology, representing only a tiny fraction of the electricity generation sector. In 2020, the collective installed capacity of floating solar panels reached a modest 3 GW (Gigawatts), while land-based solar systems outpaced them significantly, boasting over 700 GW. However, if we were to extend floating solar coverage to 10% of the world’s hydropower reservoirs, we could establish an impressive 4,000 GW of solar capacity, equivalent to the combined electricity-generating capacity of all operational fossil-fuel plants worldwide.

Typical Representation of Large Scale Floating Photovoltaic System. Source: SERIS, National University of Singapore.

Benefits

1. Floating Photovoltaic Technology is expected to generate about 11% more electricity than land Photovoltaic systems due to the cooling effect on the panels caused by water evaporation.
2. The next benefit is the generation of electricity without emissions of CO2 (Carbon dioxide) or noise generation during its operation. CO2 savings reported in the literature vary from 0.53 kg CO2/kWh to 0.6–1.0 kg/kWh.
3. By reducing water evaporation in covered areas, they help conserve water and can be especially valuable in regions prone to drought.

Challenges

While floating photovoltaics offer numerous benefits, they are not without their challenges.

1. Shading a significant portion of a reservoir can have cascading effects, potentially hindering the growth of photosynthetic organisms like aquatic plants and phytoplankton.
2. Furthermore, societal uses of these reservoirs may be compromised, particularly if a project interferes with local fisheries, impacting the livelihoods of communities already affected by reservoir construction.
3. There are still substantial uncertainties regarding the environmental impacts of this technology, and research in its social, technical, and economic dimensions is limited. Addressing these knowledge gaps promptly is crucial.

While challenges exist, the imminent growth of this technology shows the urgent need for more prompt scientific research and policy development to ensure its sustainable integration of this technology in our battle against climate change.