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Underwater Pumped-Storage Hydroelectric Project Completes Its First Practical Test (forschung-energiespeicher.info)
What if you built massive concrete spheres -- 98 feet in diameter, with 10-foot walls -- under the ocean to help generate electricity during peak periods? Slashdot reader nachtkap reports that German researchers just finished testing their 1:10-scale prototype StEnSEA:
It was retrieved from Lake Constance, where it was submerged at a depth of 100 meters [328-feet] since November. The system was developed by the Fraunhofer-Institut IWES in Kassel, Germany in collaboration with its inventors... The German Trade Department and Department of Education and Research as well as the German construction company Hochtief are also involved with the project.
The system's hollow concrete spheres are intended to be used in conjunction with off-shore wind-farms to serve as energy storage for peak hours. The spheres are ultimately supposed to be submerged near off-shore wind-farms and pumped free of water with excess energy. When additional energy is needed during peak hours the system goes into reverse and water rushes in, driving a turbine... At 700 meters the system has a capacity of 20MWh, with a linear capacity increase as depth increases.
The system's hollow concrete spheres are intended to be used in conjunction with off-shore wind-farms to serve as energy storage for peak hours. The spheres are ultimately supposed to be submerged near off-shore wind-farms and pumped free of water with excess energy. When additional energy is needed during peak hours the system goes into reverse and water rushes in, driving a turbine... At 700 meters the system has a capacity of 20MWh, with a linear capacity increase as depth increases.
Advantages that I can see;
More places they can go, and the places they go (off the coast) are usually closer to places that want the electricity.
If it works, you can scale it by building more spheres.
A change in height of 700m is easy to obtain in the ocean. On land, not so much.
Out of sight, out of mind - Since fewer people will see it, fewer will complain about it.
If a sphere fails, it's far less catastrophic than a dam failing.
Sure, but not everybody lives around Lake Constance. They have tested the system there, but the may want to use it near the coast, or at the bottom of the sea where the offshore wind farms are.
This. Offshore wind farms have lots of water, but no hills and no place to pump water.
Pumped hydro is great, if you have the water and the geography to impound the water.
The ultimate end of this thought-experiment is just to use water.
No bullshit grab-for-the-stars (and never get them) waste of money and time, but practical, pragmatic and addressed at real problems. Of course, this will take another 10 years or so to practical deployment, but it is highly likely to work and be both reliable and cost-effective. Things like these drive progress.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
Have these people ever lived by the sea? There is no way a pump is going to sit at depth without needing to be taken out and cleaned every few weeks. There is no way the generator turbine is going to sit at depth without getting furred up. There is no way the influx and drain pipes will remain clear. Even the sphere itself will slowly fill.
The sea is not just salty water. It's a soup of animals, plants and minerals in suspension. The test might work in a fresh water lake for a few months but the sea is far more active at destroying machinery. Otherwise we'd just build big turbines and let the tides generate all of our electricity.
Death trap for whom ?
By death trap do you mean 'non-zero' risk similar to the people who live below a hydroelectric dam, or near a nuclear power plant, or who mine coal, or who live downwind from a dirty coal plant ? I suspect the human risk is pretty low comparably.
if you mean the critters living nearby, we eat around 100M tons of fish / year, so that might be a better place to focus in terms of 'death trap'.
If they plan to use it in salt water, they should be testing it in salt water. The problems aren't the same. It may still be a good idea, but testing it in fresh water worries me. Of course, this may be an early prototype...but they damn well better be testing the pilot in salt water...if it were near where I live I'd say they also need to be testing it in winter storms, but perhaps they're planning on using it in a sheltered area.
I think we've pushed this "anyone can grow up to be president" thing too far.