Reply to: Pumping genius

[d000hg]

Didn't some bloke try to get that on the mouth of the Severn?

There have been LOADS of tidal and wave projects that never went anywhere. A friend was working for one in SCotland just the other year. Not sure if it's just too difficult, or there hasn't been the financial reward to get the big boys involved - all the ones I've seen have been university research which is interesting then gets washed up in pieces after a big storm.

I had always backed wave/tide over wind but it looks like if they can crack storage, that might be proved wrong.

[NigelJK]

Didn't some bloke try to get that on the mouth of the Severn?

[vetran]

Best place to put one of those is inlet just below high water and outlet just above low water at the coast, preferably on a sloping beach. Let the Moon do the heavy lifting.

Tidal power needs storing as well, though being close to land a hydrogen generation plant makes sense no need to pump it far.

As you suggest it could be the basis for simple tidal power but as above lagoons do that cheaper with the added attraction of girls in Bikinis on surfboards.

[d000hg]

Best place to put one of those is inlet just below high water and outlet just above low water at the coast, preferably on a sloping beach. Let the Moon do the heavy lifting.

It's not the best place when wind warms are moving off-shore. The blight* of every square inch being covered with a forest of wind turbines may not last long.
Artificial lagoons have been proposed in this vein though, basically extending the coast 100m out to create vast shallow reservoirs that can be used for tourism and watersports, etc.


* I quite like them but there are getting to be rather a lot.

[NigelJK]

Best place to put one of those is inlet just below high water and outlet just above low water at the coast, preferably on a sloping beach. Let the Moon do the heavy lifting.

[northernladuk]

its offshore Hydro same idea as a dam and pumped storage but without flooding villages and destroying habitats. There is no reason why deep lakes can't use these as well.

I seem to remember a programme on TV awhile ago about using reservoirs and lakes being a problem due to lack of current so any floor fixings are next to impossible. They have very think silt where as the sea bed in shallower areas the rock base is more exposed. There was also the nature issue with them being a closed environment (more than the sea) plus general public use on lakes so narrowing down the number of ones that would be eligible to use to a small number. I'm sure it will happen but for now there are easier options it appears.
Same issues using a current or wave bobbing generation. Just needs the right tech designing I think which can't be far off.

[d000hg]

That may not be the implementation here but a stretched bladder would work in microgravity. The potential energy comes from the elastic stretching. Maybe I'd best get on that patent...

PS: you can't "contain a vacuum" that's a contradiction
PPS: at high pressure you wouldn't turn into a mist. You'd be squished to jelly.

Think you are too reliant on pop-science and James Bond films

[vetran]

The pressure comes from the tension in the stretched bladders. You famously cannot pressurise water. The water inside the tank at the bottom of the sea is under the same pressure as the water outside.

pump water into a balloon on the ISS and let go and it will still get expelled.

oh dear physics not your strong point?

In this case the bladder is containing a vacuum (so no tension) and the weight of the water above causes the water to rush into the nature abhorred vacuum driving a generator. To restore the vacuum you use an electric pump to expel the water the bladder is there solely to isolate the fluid you pump.

Note the stores without a bladder use the same rules.

Pressure is involved not the use of the words Bar's and Atmospheres. If you you were in water at a 700 bar pressure you would turn into a red and grey mist very quickly.

[d000hg]

It is relying on gravity. Where do you think the pressure comes from? The weight of the water above it, and why does the water weigh something? oh yes gravity.

What you mean is Hydro without requiring the water to fall a long way is a big deal.

The pressure comes from the tension in the stretched bladders. You famously cannot pressurise water. The water inside the tank at the bottom of the sea is under the same pressure as the water outside.

pump water into a balloon on the ISS and let go and it will still get expelled.

[vetran]

Hydro without needing to rely on gravity is quite a big deal

It is relying on gravity. Where do you think the pressure comes from? The weight of the water above it, and why does the water weigh something? oh yes gravity.

What you mean is Hydro without requiring the water to fall a long way is a big deal.

[d000hg]

Hydro without needing to rely on gravity is quite a big deal

[vetran]

Fascinating. Wonder if they've been to see Port Dinorwig - it's been there since the late seventies...

its offshore Hydro same idea as a dam and pumped storage but without flooding villages and destroying habitats. There is no reason why deep lakes can't use these as well.

Its what we need to flatten the spikes in demand, instead of firing up an old dirty coal or gas station to cover the post corrie cuppa we can use these. Also instead of turning off the wind farms we can load them with charging these.

Our grid needs stable consistent power (otherwise it overloads) but with the ability to cope with significant spikes , wind and waves aren't able to provide that but with storage they will be able to.

https://www.nationalgrideso.com/news...uro-2020-final


Maybe a hybrid solution, an on land bladder with a connection underwater? A bit like a Gasometer? Or even a complete above ground gasometer style cylinder being pumped up and down. They have been viable for centuries.

[vetran]

I assumed that was going to be this story but in fact it seems different... this relies on basically pumping it into balloons which then passively generate power when needed:
https://www.bbc.co.uk/news/business-60066690

I like the low-tech approach. Carpeting the ocean floor with huge batteries is clearly not great.

They mention the bladder version in my link and I personally think that is a winner because they can control the contents (have a sterilised water source in a rigid tank for the bladder so the pump doesn't get fouled) but use the raw atmospheres on the balloon to to shrink it. Now I'm thinking a piston and cylinder (self scraping and will last centuries with a little care) with a similar set up.

If it don't upset the marine habitat and reduce emissions significantly it sounds great to me. We are talking a few hundred feet down.

[d000hg]

You seem to have missed the part where it explains

Pumped hydro storage is one of the oldest grid storage technologies, and one of the most widely deployed, too.

They're not claiming it's a new idea. I don't think this has been done in an offshore setting though - and the future of wind is most definitely offshore.

[WTFH]

Fascinating. Wonder if they've been to see Port Dinorwig - it's been there since the late seventies...

Beat me to it.

Put wind turbines on the dam to pump the water back up.