Potential for pumped-storage hydro power in Donegal?

[riven]

The underlined words are the wrong.

You generate as many megawatts as you like at the offshore wind farm. You generate it at night, when demand is very low. You immediately use this energy, at night, to pump the water up the hill. You let the water run down the hill when you want to use or sell the energy.

I think people need to look at the clearly-written links that explain the technical details in straightforward, layman friendly language, before they post. Read the whole thread and take ten minutes to read the wikipedia links I have posted post, I suggest.

Well excuse me for being informed on energy issues. You clearly do not have a clue about what you are talking about.

I repeat this project is a laod flattening device used to generate moneny. You use more energy implementing this project.

From your loved wiki
'Although the losses of the pumping process makes the plant a net consumer of energy overall, the system increases revenue by selling more electricity during periods of peak demand, when electricity prices are highest'

So we use more electricity in storage than we generate. Lets take a very simple example.
1000 MW generated at a power plant. This is transmitted to the storage area. Average loss in transmission is 9% so we now have 910MW.
The pumps use energy to pump the water up and down the hill. Accirding to your wiki (lets keep it simple) 70-85% of the energy can be reclaimed. Knowing that pump efficiency for these sizes is at best 80% we go with the more reasonable 70% efficiency. So we now have 637 MW.
Again transmission to market result in 9% loss.
So we now have 580MW.

To store the 1000MW or what ever value you wish on a very simple analysis we lose at least 42% of the original energy generated. Not clever especially considering that our peak demand is not above our capacity. I have not taken into account turbine efficiency, friction and water evaporation.

Point being we need to generate more electricity than we currently use if we implement these. As fgor your example with wind farms, the London array for example has no plans to use pumped storage as the arrays job would be to produce power, not to flatten the load.

[HanleyS]

If you're that well informed on ernergy issues then why are you using Watts rather that Watt Hours as the unit of measurement?

[DaveM]

Listen to the interview. I haven't heard anything to suggest he's changed his mind.
http://www.politics.ie/current-affai...g-ireland.html

Firstly, Eddie O'Connor has nothing to do with Airtricity anymore. His new company is developing renewable projects all over the world including Ireland. The fact that he is not happy about the ESB isn't really news to anyone. It doesn't mean he won't work in Ireland. Michael O'Leary is no fan of the DAA... do you see him pulling out of Dublin Airport? No. Because he can make a profit here and Eddie O'Connor is no different.

[DaveM]

If you're that well informed on ernergy issues then why are you using Watts rather that Watt Hours as the unit of measurement?

Thank you!!!!!!! This seems to be lost on most people!

[riven]

If you're that well informed on ernergy issues then why are you using Watts rather that Watt Hours as the unit of measurement?

Really cop on. If you knew anything about simple unit conversions you would know that there is no issue.

Watt hours = watts * hours.

On the ground in industrial facilities, items of equipment and power outputs are rated in Watts/kW/MW which is directly related to motor size and required process power.

When buying a pump from a pump manufacturer the manufacturer will specify the pump rated on Watts or kW not watthours.

[orbit]

Thank you!!!!!!! This seems to be lost on most people!

Including it seems the ESB ....



It's no wonder that people are getting obsessed about PSH, when the ESB claims that Turlough Hill generates 292 MW without any caveat, relating to the time it's able to sustain it for.

[riven]

Not to mention that the power reclaimed is not 292 MW but a lot less

[DaveM]

Including it seems the ESB ....

It's no wonder that people are getting obsessed about PSH, when the ESB claims that Turlough Hill generates 292 MW without any caveat, relating to the time it's able to sustain it for.

The ESB aren't the ones advocating it's use as a large scale storage device for supply variation. The ESB, and anyone who clearly understands what Turlough Hill is actually for, would know that it is sized to cater for demand variation on the grid and no more.

[orbit]

The ESB aren't the ones advocating it's use as a large scale storage device for supply variation. The ESB, and anyone who clearly understands what Turlough Hill is actually for, would know that it is sized to cater for demand variation on the grid and no more.

Yes, we know that, and the ESB knows it, but any lay person reading that table might not realise it, which may explain the ludicrous argument on this thread. Reading that table you could easily think Turlough Hill was equivalent to all the other hydro stations put together.

[Finbar10]

There was a physicist from TCD on about this recently. But I don't think he had many specific ideas/locations in mind. To understand the scale of the task, consider that Turlough Hill can generate 292MW, but only for a few hours, because the lakes only hold that much water. 292MW is also a drop in the ocean, in terms of daily electricity demand.

Yes, a physicist from Trinity was on about this a few months ago
(see Think tank: A high energy solution - Times Online).
He sounded convincing enough to me at the time, but when I afterwards tried plugging in some actual concrete figures and estimating how much water would realistically need to be stored I become much less convinced.

He proposed that pumping water up 250m into a lake 2km by 2km in size and 20metres deep would be enough to supply Ireland's energy needs. I wondered roughly how long could such a lake could power Ireland for.

If my calculations are correct, assuming 100% perfect efficiency, such a lake could supply Ireland with energy for only 13 hours. To supply Ireland with energy for a week, a lake 250m above sea level and depth of 20m would need to be roughly 7.5km x 7.5km in size !! Pretty big to say the least. Or would require 56 smaller 1km x 1km lakes.

The following physics seems correct to me (please correct me otherwise, it has been a long long time since I studied basic physics! ) ).
To raise an object of 1kg the height 1 metre requires 9.8 joules of energy (the 9.8 comes from the coefficient for gravity).
1 litre of water weighs almost exactly 1kg.
A 2km x 2km x 20m lake contains 20,000 x 20,000 x 200 = 8 x 10^10 litres (8e10 litres) of water. Raising this 250m would store 250 x 9.8 x 8e10 joules = 1.96e14 joules.
Average electricity consumption in Ireland is I think 4 giga watts, i.e. 4 billion joules (4e9 joules) being consumed per second. Assuming perfect efficiency the reservoir would last for just 1.96e14/4e9 = 49,000 seconds = 13 hours.
A 7.5km x 7.5km lake would last for roughly a week.