sustainable energy

More floating solar

September 25, 2025 By EarthWise Leave a Comment

Floating solar power is starting to gain some traction in the United States. Installing solar panels on rafts so that they float on water instead of sitting on land allows them to not take up land that can be used for other purposes. There are other benefits as well.

The world’s largest floating solar farm is one in Shandong, China, and produces 320 MW of power. Floating solar has been common in Asia for years. To date, floating solar only makes up a tiny fraction of the installed solar power in the U.S. and is mostly limited to small-scale projects. The largest in the U.S. is the 8.0 MW Canoe Brook Water Treatment Plant in Millburn, NJ. A floating solar array in the water reservoir at the Cohoes Water Filtration Plant in New York’s Capital Region is currently under construction. A 6-MW floating solar system is now being built in the Village of Monroeville, Ohio.

Floating solar systems have the advantage that covering the surface of reservoirs dramatically reduces the amount of evaporation that occurs, which is a real benefit in drought-stricken regions like California. In addition, proximity to the large body of water keeps solar panels cool, which allows them to generate more electricity than their land-based counterparts.

Estimates are that federally controlled reservoirs alone have the potential to host roughly 1,000 GW of floating solar capacity. It is more expensive to install them than conventional land-based solar and floating solar competes with recreational use of bodies of water. Nonetheless, the floating solar market is expected to grow significantly in the coming years.

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Ohio’s largest floating solar array is now under construction

Photo, posted May 28, 2025, courtesy of Mike Popp / University of Arkansas via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Vertical-axis wind turbines

February 19, 2025 By EarthWise Leave a Comment

Nearly all wind turbines in use today are horizonal axis wind turbines. They are a familiar sight with their three giant rotor blades spinning about an axis high above the ground attached to a nacelle containing the gearbox and generator.

A vertical-axis wind turbine has its rotor shaft transverse to the wind; that is, the shaft rises up from the ground and the gearbox and generator are located close to the ground.

This type of wind turbine does not need to be pointed into the wind, which eliminates the need for wind-sensing and orienting mechanisms. It is also considerably quieter in operation than horizontal axis wind turbines. Vertical-axis wind turbines have enjoyed minimal success to date because of a variety of problems including reliability issues and complications related to how they respond to changing wind conditions.

A next-generation vertical wind turbine is going on trial in Australia as part of a research collaboration between Flinders University in South Australia and the start-up company VAWT-X Energy. The 6KW prototype will be installed at a field site in Australia’s Fleurieu Peninsula.

According to the developers, the new turbine design will be as efficient, or even more efficient, as existing horizontal turbines and will be able to thrive across diverse environments including being part of urban infrastructure where their relative quiet is a real advantage. Such turbines would be more accessible for applications like off-grid power and sustainable energy solutions for small businesses and farms. The developers claim the technology can also be scaled up for large-scale windfarms.

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Progress with new-look wind turbine

Photo courtesy of VAWT-X Energy.

Earth Wise is a production of WAMC Northeast Public Radio

Record Renewable Use In California | Earth Wise

May 19, 2022 By EarthWise Leave a Comment

California, the most populous state, is the second largest electricity user. Only Texas, the second most populous state, uses more energy, in part because it consumes large amounts in refining fossil fuels. Overall, California uses about 8% of the electricity generated in the U.S.

Thus, it was a significant milestone when briefly, on April 3, a record 97.6% of the energy on California’s statewide grid came from renewable energy resources. (The previous record of 96.4% was set just a few days earlier).

Renewable energy’s share of the power typically peaks in the spring when mild temperatures keep demand relatively low and higher sun angles drive greater solar energy production.

On April 8, a record peak solar power production was set at 13,628 megawatts just after noon. On March 4, the state set an all-time wind generation record of 6,265 megawatts.

California now has over 15,000 MW of grid-connected solar power and 8,000 MW of wind. Another 600 MW of solar and 200 MW of wind are coming online by June. The state also has about 2,700 MW of energy storage online and that will climb to 4,000 MW by June.

In 2020, 34.5% of the state’s retail electricity sales came from wind and solar sources. Adding in hydropower and nuclear power, nearly 60% of the state’s electricity came from non-fossil fuel. Despite the effects of drought on hydropower generation and the impact of the pandemic on the pace of renewable energy projects, California continues its dramatic transition to sustainable energy.

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Solar and wind notched records as renewables met California’s energy demand

Photo, posted September 20, 2016, courtesy of Tom Brewster Photography / BLM via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.