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Hydropower And Floating Solar | Earth Wise

October 30, 2020 By EarthWise Leave a Comment

According to a new analysis by the National Renewable Energy Laboratory, hybrid systems of floating solar panels and hydroelectric plants have the potential to produce a significant portion of the world’s electricity.

According to their estimates, adding floating solar panels to bodies of water that host hydropower stations could produce up to 7.6 terawatts of power a year from the solar systems, resulting in about 10,600 terawatt-hours of energy. The total global electricity consumption in 2018 was 22,300 terawatt-hours. So, the potential in terms of the global appetite for electricity is very large.

This estimate is certainly optimistic. It does not take into account economic feasibility or specific market demand. What it does represent is an estimate of the technical and performance potential of floating photovoltaics at hydroelectric facilities.

Floating solar is just starting to be used in the U.S., but it has already caught on overseas where space for ground-mounted systems is at a greater premium.

According to the NREL study, nearly 400,000 freshwater hydropower reservoirs across the globe could host floating PV sites that could be used in conjunction with the existing hydroelectric plants. One important advantage of this approach is that the hybrid system would reduce transmission costs by linking to a common substation. In addition, the two technologies could balance each other, with solar power taking up the slack in dry seasons and hydropower working well in rainy seasons. In some places, pumped storage hydropower could be used to store excess solar generation.

There is great potential in hybrid floating solar/hydroelectric power.

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Untapped potential exists for blending hydropower, floating solar panels

Photo, posted April 12, 2009, courtesy of Alexis Nyal via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Forecasting A Massive Dead Zone

June 18, 2019 By EarthWise Leave a Comment

The Gulf of Mexico dead zone occurs every summer, and is considered one of the largest dead zones in the world. This cyclical event occurs where the Mississippi River empties into the Gulf of Mexico, just off the coast of Louisiana and Texas.

This annual dead zone is primarily caused by excess nutrient pollution from human activities, such as urbanization and agriculture, occurring throughout the Mississippi River watershed. Washed off the land by spring rains, these excess nutrients stimulate an overgrowth of algae once they reach the Gulf of Mexico. The algae in the Gulf eventually die, and then sink and decompose in the water. The resulting area of the ocean ends up with a condition known as hypoxia, which is an insufficient amount of oxygen to support most marine life. In hypoxic or dead zones, animals that can’t swim away will often suffocate and die.

Scientists from the National Oceanic and Atmospheric Administration estimate that this year the dead zone in the Gulf of Mexico will be approximately 8,000 square miles, which is roughly the size of Massachusetts. The research team uses U.S. Geological Survey river flow and nutrient data to make its forecast.

According to NOAA, the abnormally high amount of spring rainfall is a major factor contributing to this year’s dead zone. Last month, nitrate loads entering the Mississippi River watershed were 18% above the long-term average, and phosphorus loads were about 49% above the long-term average.

While the 2019 forecast is slightly less than the record size of more than 8,700 square miles set in 2017, it’s still much larger than the five year average size of 5,700.

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Very large dead zone forecast for the Gulf of Mexico

Massive 8,000-mile ‘dead zone’ could be one of the gulf’s largest

Photo, posted May 22, 2009, courtesy of Michael McCarthy via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Ton Of Plastic Per Person

October 27, 2017 By EarthWise Leave a Comment

A study by the American Association for the Advancement of Science has produced an estimate of the total amount of plastic manufactured worldwide since the 1950s. The researchers then measured that data against statistics on recycling, incineration and discard rates. The results are sobering.