Two New Renewable Energy Technologies That Just Might Work

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Continuing CleanTechnica’s never ending quest to keep readers informed of new developments in the world of renewable energy, we bring you word of two new developments that clattered forth from the teletype machines in our state of the art newsroom in the third sub-basement just below the executive gymnasium. The first news flash came from Fraunhofer, the highly respected German technology research organization. The other is the O-Wind Sphere from O-Innovations that promises free electricity from prevailing breezes.

Undersea Storage For Renewable Energy

Pumped hydro energy storage has been around for decades. It is a lot like hydroelectric power except instead of just harvesting the energy in flowing water, it recaptures that water, pumps it back uphill, and reuses that to generate more electricity later. Now, that may sound to some like a perpetual motion machine, which we all know is a scientific impossibility. Doesn’t it take more energy to pump the water back uphill than is created when it flows downhill?

The answer is, of course it does. The secret sauce that makes the process economically feasible is that the value of electricity varies according to availability and demand. At some times of the day, electricity costs more because demand is high. At other times, it costs less because demand is low. If you can sell the electricity from a pumped hydro facility when the price is high, you can wait until the price is low to pump it back uphill. If properly managed, it is possible to create profits even if the the energy equation is out of balance.

Pumped hydro has a number of problems, however. One, it takes up a lot of room. Two, it can take years to construct a new pumped hydro facility. Three, new pumped hydro installations can be expensive. Fraunhofer has what it thinks is a better idea. Build a bunch of large concrete spheres and place them on the floor of the ocean at a depth of about 2000 feet. According to NOAA, “The pressure increases about one atmosphere for every 10 meters of water depth. At a depth of 5,000 meters the pressure will be approximately 500 atmospheres or 500 times greater than the pressure at sea level.”

Now, dear reader, work with me here. It is well known that my brain turns to mush when confronted by mathematical challenges. 2000 feet is about 600 meters. 600 divided by ten is 60, so at that depth, the pressure of the water outside the sphere will be 60 times greater than it is at sea level. Open a portal to let the sea rush in, and it will have more than enough force to spin a turbine to generate electricity.

The business case for doing this is the same as it is for pumped hydro. Make electricity when the price is high, pump the water back into the ocean when the price is low. Voila! Fraunhofer estimates the cost of its system at $177 (€158) per kWh. By comparison, the National Renewable Energy Laboratory in 2023 estimated the cost of battery electric storage at between $245 and $405 per kWh.

Fraunhofer calls its idea StEnSea — Stored Energy in the Sea — and it has been developing the technology since 2011. Now a pilot project that will drop a ball 30 feet (9 m) in diameter into the ocean off of Long Beach California is set to begin by the end of 2026. It is expected to generate 0.5 MW of power and have a capacity of 0.4 MWh — enough to power a typical US home for about 2 weeks. The west coast of the United States was chosen because the ocean floor drops off quickly. On the east coast, the continental shelf extends far to the east. One of the cost considerations for StEnSea is how much electrical cable is needed to connect the sphere to the shore.

Assuming the pilot project is successful, the next goal is to test larger spheres 100 feet (30 m) in diameter. Fraunhofer calculates that StEnSea has a theoretical storage potential of 817,000 GWh, which would be enough to power 75 million homes in Germany, France, and the UK for about a year. According to New Atlas, the US Department of Energy has invested $4 million in the StEnSea project. Readers are free to draw their own conclusions about whether that financial support will continue now that the fossil fuel crowd owns two of the three branches of the US government.

The potential downsides to this technology include the need to provide security for the undersea cables connecting the system to the mainland. This is not theoretical, as the NordStream pipeline explosion makes clear. Not only that, Russia seems to have developed a fleet of ships that somehow always manage to drag their anchors in the immediate vicinity of undersea cables.

O-Wind Sphere Better Than Solar Panels?

Like the Fraunhofer StEnSea project, the O-Wind Sphere has been in development by O-Innovationss for a number of years. On its website, the company says, “As the global population grows, our cities also increase in height and density, receiving less sunlight and experiencing more wind at ground level. To generate the necessary energy for our cities locally, we must harness this strong and chaotic wind. The O-Wind is the first truly omni-directional wind turbine specifically designed to address this challenge, making it perfect for urban use.”

The O-Wind won the Dyson Award in 2018, prompting James Dyson to say, “The O-Wind Turbine takes the enormous challenge of producing renewable energy and using geometry it can harness energy in places where we’ve scarcely been looking — cities. It’s an ingenious concept,” DesignBoom reports “The O-Wind Turbine from O-Innovations relies on Bernoulli’s principle to make its mechanism work. Vents have large entrances, but smaller exits, which create a different pressure inside when the wind enters, causing the turbine to move. The vents cloak the sphere’s structure to make the turbine receptive to all directions.”

Small wind turbines may have a place in the energy generation sector in the future. Whether the O-Wind is a viable concept on a commercial scale remains to be seen.

And The Winner Is …

There are precious few technical details available about the O-Wind, which suggests it may be an interesting concept but will not bring copious amounts of renewable energy to the people of the world anytime soon. The StEnSea project, on the other hand, is backed by real scientists doing things real scientists do. Is it likely to replace BESS? No, it won’t play in Oklahoma City or Memphis, which are far from any deep oceans, but it is a potential tool to help move the renewable energy revolution forward in places where politicians are not shills for fossil fuel interests.

Over watercress sandwiches (with the crusts cut off, naturally), the gang at CleanTechnica thought the Fraunhofer StEnSea technology will find a niche in the energy storage world in the near future. The O-Wind? Not so much. Check back with us in 2030 for a full report!