Floating Solar Farms Join Other Novel Over-Water Ways to Get to Net Zero

Jane Marsh has become a frequent contributor of content to 21st Century Tech Blog. When she sent me the article that follows I quickly looked back to another recently published piece which looked at renewable over-water solutions. The article I wrote and published in September featured the Wind Catcher, a floating array of small wind turbines designed to endure for a half-century with minimal maintenance, and currently backed by General Motors.

What Jane is describing is complementary to Wind Catcher and if I were an energy utility company looking for green solutions, I’d be paying considerable attention to solar farms on water and Wind Catchers.

Solar farms provide utilities with unique solutions to solve their goals of lowering the carbon footprint of the energy they deliver. But solar power is challenged by the need to be in sunlight. Not all locations provide enough hours of direct sunlight every day. Many rooftops aren’t designed to take solar panels. But one of the biggest challenges is that large arrays of solar panels, called solar farms, can take up a lot of space tying up hectares of land that can be used for alternative purposes such as growing crops. As a result, an emerging alternative implementation of the technology is focused on building solar farms over water rather than land. 

What Is a Solar Farm?

A solar farm, also known as a photovoltaic power station, is a large collection of solar panels placed in one area connected to the grid. The first solar farm was launched in 1982 in Hesperia, California. Since then, utilities and companies have built many more. The usual locations are where there are few people, ample sunlight, minimal wetland habitat and flat surfaces. This helps to maximize their efficiency. 

Why Place Solar Farms on the Water?

Farmers and conservationists don’t always approve of land-based solar farms because the installations cover areas that can be used for growing crops, grazing livestock, or preserving wildlife. A solar farm can impede a wildlife corridor and range where migratory animals and grazing animals travel regularly. A solar farm could cover an area that is home to sensitive and endangered plant species that require full sun. The shadow cast by the panels could disrupt their growth.

In some countries, India for example, there simply isn’t space for land-based solar farms. With its rapidly growing population, India needs to conserve all the land it can for food production. That’s why floating solar farms are seen as appealing. The waterways, reservoirs and oceans upon which they ride will never be used for farming and raising livestock. Although, in the future, we may see floating cities built which would make floating solar farms a valuable energy-producing adjunct to these novel human settlements. 

From companies maintaining overwater infrastructure, particularly in ocean environments, there are unique challenges caused by saltwater interacting with sensitive equipment. Currently, a growing technological capacity to maintain equipment in these environments should be transferable to floating solar farms soon.

Ecosystem Impacts from Floating Solar Farms

Where to Find Floating Solar Farms Today

Aquatic solar farms are becoming more common worldwide. Here are a few countries using this technology:

India

On the Omkareshwar Dam, the state of Madhya Pradesh is constructing a giant floating solar plant. The plan is to have it operational by 2023. The panels will be able to automatically adjust their position based on fluctuating water levels. 

United States

In California, the Healdsburg Floating Solar Farm is situated at a wastewater treatment plant. It’s the largest floating solar farm in the United States. The two-sided panels capture energy from the sun above, and also from below as it reflects off the water. 

Thailand

The energy plant on the Sirindhorn Dam has the claim to fame as the world’s largest floating solar farm. Comprised of over 144,000 individual panels, the massive plant generates energy from both solar and hydropower. Since it became active a year ago, it has already generated 60 million kilowatt hours of electricity.

Germany

Floating on a lake that formed in an unused quarry near the town of Haltern am Sea, this floating solar farm is the largest in the country providing 3 Megawatts of power. It is one of many renewable energy projects that Germany hopes will help it to wean itself off fossil fuels coming from Russia in the wake of the war in Ukraine. 

Portugal

Europe’s largest floating solar farm can be found on the Alqueva Reservoir. Its 12,000 panels are supplying enough energy for up to a third of the residents in nearby towns. 

Where to Find Floating Solar Farms Tomorrow

This week a Dutch-Norwegian joint venture is planning to deploy a floating solar farm combined with an offshore wind farm off The Netherlands. The company, SolarDuck, will be the first to build a hybrid demonstrator project at this scale. It is one of several planned and under-construction pilot over-water solar farm projects currently on the go and will be located 53 kilometres (33 miles) offshore.

The growing interest globally for floating solar farms is being driven by climate change and a solution that doesn’t take up valuable land suitable for growing food. Combined with other over-the-water renewable energy solutions like wind farms as planned by SolarDuck and others, the technology should see significant growth through the rest of this decade and beyond. Market perceptions are very positive. Valued at US $2.55 billion in 2021, the floating solar farms’ industry is expected to grow to more than $10 billion by 2030. Why? Utilities see advantages in deployment because they are scalable, easy to assemble, adaptable, and can be integrated with other renewable technologies like wind on and over the water.