Turning pressure into electricity? "Ocean battery" technology opens up a new track for green energy

According to Agence France-Presse, the "ocean battery", which was recently unveiled at the exhibition, provides a new solution for renewable energy.

Wind turbines that stand still on windless days or are still spinning rapidly when power needs are met are a problem for renewables and one that researchers believe can be solved on the seabed. According to one scenario, offshore wind farms will use seawater to make the necessary storage of energy that is not yet needed, thus helping humanity wean itself off its dependence on fossil fuels.

Fritz Blick, CEO of Dutch startup Ocean Grazer, said of presenting the system at the Consumer Electronics Show in Las Vegas: "We came up with a solution that we call 'ocean batteries.'" ”

In the context of countries' increasing push to reduce the use of energy sources that contribute to climate warming, such as coal, green energy storage technologies will be key, experts said.

That's because nature doesn't always provide wind or solar energy when people need electricity most.

Blick's "ocean batteries" rely on huge sacs set on the ocean floor, filled with seawater pumped in by wind power from wind farms. When electricity is needed, the pressure of the ocean squeezes out the energy storage system located on the seabed with turbines inside it – and the result is the generation of electricity.

A key consideration related to energy is cost, and energy storage systems that utilize some type of chemical battery are not only very expensive, but also run the risk of leaks or pollution in the marine environment.

Pressure-dependent energy storage systems have been adopted in dam-type hydropower plants: these hydropower stations pump water into the reservoir behind the dam when the demand for electricity falls, thus effectively storing electricity so that it can be restored to electricity later by the hydropower plant's turbines.

The U.S. Department of Energy believes that this concept, known as "pumped storage hydropower," dates back to Italy and Switzerland in the 1890s, although such hydropower plants can now be seen all over the world.

As for the submarine version of this energy storage method, Ocean Grazer is not the only company that is trying to put it into practical use.

FLASC is an independent company from the University of Malta. The company has developed a system that uses electricity made in a renewable way to pump water into a container containing negative pressure gas, which can then push the turbine to generate electricity.

Another idea, StEnSea (Offshore Energy Storage), was to use hollow concrete spheres set on the seabed, under deep-sea pressure, and tested it in a lake in Germany in 2016.

Blick, CEO of Ocean Grazer, said subsea energy storage systems take advantage of no cost seawater pressure, and their energy storage efficiency is as high as about 80 percent.

He believes that energy storage systems are the key to renewable energy. As the production costs of renewables fall, they have grown rapidly and become a steadily rising share of the world's energy mix.

According to the Center for Climate and Energy Solutions, a nonprofit organization in the United States, renewables are the fastest-growing energy source in the United States, growing by 42 percent from 2010 to 2020.

However, it will take many years for systems like "ocean batteries" to be promoted on the scale of regular members of the grid.

Bleecker said his company intends to build an offshore system by 2025, although an onshore system will be built in the northern Netherlands by 2023.

While the variety of practices of storing energy through stress is nothing new, pairing it with green energy has enormous potential.

Claudio Canizal, an engineering professor at the University of Waterloo in Canada and a renewable energy expert, said: "It's extremely exciting at a time when wind and solar are now part of the grid – basically freeing us from fossil fuels. (Compilation /Cao Weiguo)

Source: Reference News Network