at last the renewable energy mammoth sized battery !

[allstarz]

Ladies and Gentlemen,
the matt 'n' fionn plan for storing renewable energy
is as follows.

Take one windfarm on a hill somewhere,
or one underwater tidal current farm.
When electricity production is high,
and consumer demand is low, like at night....

Switch the power to raising water, like in turlough hill

http://www-cenerg.cma.fr/more-care/activities/turlough_hill/turlough_hill.html

except this time the energy used to raise the water is renewable.

A coastal tidal current generator like the davis energy turbine,

http://www.bluenergy.com

, could also be used purely in conjunction with a mechanical pump, with no electrical generator attached, to pump water up into a reservoir on a cliff, ready for release down onto a turbine just above sea level.

remember you can use either the route by which you generate electrical power, to run the pump, or physically connect the moving parts of the windmill or undersea mill to the pump.

this is the much talked about battery, that renewable energy has required to become effecient and effective.
best regards
Fionn

 

[btrueblood]

It's the same procedure as used at Grand Coulee Dam in Washington State.

 

[btrueblood]

Yes, but...

Grand Coulee stores water in the Grand Coulee by pumping it up from Lake Roosevelt (the lake behind the dam). The pumps can also operate in reverse (i.e. as generators), providing peak generation capability. My point being the idea is not new.

Yes, your idea makes sense as a power storage system. You still need a place to create a reservoir, and deal with the people displaced by the lake you create. I've also heard of plans to use abandoned mine shafts and/or oil wells: pump air into the (sealed) cavern during off-peak hours, then allow the air to flow through generation turbines during peak loads.

 

[buzzp]

The idea is not new as pointed out. I just toured Coulee last summer and remember this system well.

I do like the idea applied to green power generators, eliminating the cost and maintainence of batteries.

 

[buzzp]

Ooops! Now you need the cost of a different turbine (at minimum) and probably another generator (unless you want to swap the driving mechanism of ONE generator - ie wind turbine with hydro, etc, probably not real feasible or cost effective so two generators/two turbines).

 

[tinfoil]

Hydro Quebec uses this scheme on a grand scale every single day to pump water back up into their huge reservoirs near James Bay using electricity generated by nukes in New England during off-peak periods, and transmitted northwards over their HVDC sysem.

They then sell the power back to the New England utilities the very next day when the value of the MWh is much higher. I understand that their round trip efficiciency is better than 90%.

The power being transferred is somewhere in the GW (1000MW, or 1 000 000 kW) range.

 

[Bung]

There is 4x250MW pump storage scheme in South Africa that is pretty impressive to see. 480m or so head, 2x6m diameter pipes to carry the water and a couple of very big dams. The sight of the saucer-shaped depression in the surface of the water in the top dam at full generation is a bit frightening, likewise the similar bulge in the bottom dam! It needs around (from memory) 14 hours pumping for 12 hours generation. The machines are both generators and synch. motor pumps.

But energy storage in the potential energy of water needs quite significant quantities of water, and apart from salt water, most of the world needs it more for drinking and food production than for making light bulbs glow...


Bung
Life is non-linear...

 

[M1Can]

Sir Adam Beck Station (Niagara Falls) has a similar pump generating station. The same turbine operates as a pump at night pumping water from the headgates of Beck II to a resoirvoir above. During the day the power can be generated as the water flows from the resoirvoir and there is also additional water volume available for the Beck II units.

Its been around a long time, not sure if they actually use it or how effective it is ( remember it from a summer student work term a long time ago)

M1 Engineering

http://www.m1engineering.ca