Potential for pumped-storage hydro power in Donegal?

[mollox]

There is not enough tidal flux at Killary and fiven that it is ouronly fjord it will not be possible because the environmental impact would be considerable.

Forget about the ecological/other concerns for the moment. It’s the concept I’m testing – if it has merit, suitable less sensitive locations could probably be identified.

I’ve picked Killary Harbour & Achill Sound as examples because of their physical structures and the limited construction required to create a very sizeable sea-water/tidal reservoir.

While the tidal flux might not be ideal, could they be used to recreate a maritime version of the Turlogh Hill concept?

A dam is built across the fjord/estuary at a point protetcted from direct storm action.
The incoming tidal flow generates a moderate amount of electricity, while also filling the internal reservoir to its “natural” depth. You then utilise off-peak electricity to pump more sea-water into the reservoir, releasing it as required to meet demand at peak times. If there’s a river flowing into the sea at the location, this will assist the filling process.

“But what if peak demand coincides with high tide, so that the outflow through the turbines is hampered by the pressure from the raised external water level” I hear you ask?

You build a series of these reservoirs at a variety of locations around the coast so that you’ll never have high tides in all locations.

The benefit of this scheme is the reliability of the power generation source. Tidal tables can be accurately produced for the coming year (and more), so it should be relatively easy for grid management to plan generation capacity/need from the individual maritime reservoirs.

Otherwise, we’re back to the ERB solution, and you don’t want that!

[HanleyS]

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.

Your statements and calculations were meaningless. I could easily take energy from a 15MW Wind Turbine and store it in a PSH reservoir to later generate 300MW. Do I really need to elaborate on this?

[HanleyS]

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.

The overwhelming majority of Airtricities activities are/were outside of Ireland. I believe Eddie's new company will be no different due to the regulatory and political environment in Ireland.

[DaveM]

The overwhelming majority of Airtricities activities are/were outside of Ireland. I believe Eddie's new company will be no different due to the regulatory and political environment in Ireland.

Not really. They already have quite a few projects in Ireland at development stage. In saying that they've set themselves up as a global operation and Ireland is just one country so it's not that surprising that more of their business is outside of the country than within it.

Your point on the regulatory and political landscape is very valid though. Getting a new plant connected to the grid is the primary issue and while ESB Networks retain responsibility for capital investment in transmission infrastructure they will to continue to make life difficult for potential competitors. The fact that this still has not been transferred to Eirgrid gives a sense of the industrial relations timebomb that are the ESB unions.

[riven]

Your statements and calculations were meaningless. I could easily take energy from a 15MW Wind Turbine and store it in a PSH reservoir to later generate 300MW. Do I really need to elaborate on this?

I have elaborated on this. Using a very simple calculation I have shown that to store that 300MW will require the use of at least 517MW reworking my calculations. That that is not considering factors such as turbine efficiency. Please provide on where you prove your point.

I repeat as pumped hydro storage is a load flattening device and since our peak capacity is well within our demands, why bother building more load flattening devices? To use these we need to use more energy that we already are which is just stupid.

And would you mind elaborating on why my statements are meaningless, if you are saying that the use of Watts as a basis of comparison is wrong then you really do not know what you are talking about? Watts is the basis of all comparisons of heat energy and power in industrial setting. Actually better still why dont you go up turlough hill and look at the stamps on the pumps, you will see watts.

[DaveM]

riven, if we're discussing PSH as a means of large scale energy storage then the MW rating of the facility is not as relevant as the energy storage capacity, i.e. how many units of electricity are stored. The fundamental point here is that the cost of the plant, in the context of large scale energy storage arising from a variable supply of renewable energy, is dictated primarily by the volume of the lake, not by the rating of thr turbines. To me that's where the economic case for their use in this application hits the rocks.

Where catering for demand variation is the primary purpose then the output rate is of more relevance and it will dictate the size of the upper lake required based in simplistic terms on the maximum length of time the system would need to operate for continuously.

As for power losses, no system is 100% efficient and nobody familiar with such systems would suggest that they are. The actual losses would have to form part of any cost-benefit analysis on a proposed system.

[odie1kanobe]

Capital expenditure costs for construction are finally falling all over the 1st world.

The fundamental issue is: is Ireland forever incapable of getting good VFM from construction projects? i think we can probably fix our excessive costs problem, you don't .

Project would take 3 years to be at construction phase and by that stage costs would be back to what they were.

[Finbar10]

I have elaborated on this. Using a very simple calculation I have shown that to store that 300MW will require the use of at least 517MW reworking my calculations. That that is not considering factors such as turbine efficiency. Please provide on where you prove your point.

I repeat as pumped hydro storage is a load flattening device and since our peak capacity is well within our demands, why bother building more load flattening devices? To use these we need to use more energy that we already are which is just stupid.

And would you mind elaborating on why my statements are meaningless, if you are saying that the use of Watts as a basis of comparison is wrong then you really do not know what you are talking about? Watts is the basis of all comparisons of heat energy and power in industrial setting. Actually better still why dont you go up turlough hill and look at the stamps on the pumps, you will see watts.

My understanding is that Watts measure the *rate* of energy usage. If power consumption is one Watt you are using energy at a rate of 1 joule per second. Joules measure the actual energy used. Confusingly, there are also units called kilowatt hours which I think do measure energy consumed. If one is using energy at the rate of 1000 Watts per second for an entire hour one has consumed a kilowatt hour of energy.

[Quixote]

I have elaborated on this. Using a very simple calculation I have shown that to store that 300MW will require the use of at least 517MW reworking my calculations. That that is not considering factors such as turbine efficiency. Please provide on where you prove your point.

I repeat as pumped hydro storage is a load flattening device and since our peak capacity is well within our demands, why bother building more load flattening devices? To use these we need to use more energy that we already are which is just stupid.

And would you mind elaborating on why my statements are meaningless, if you are saying that the use of Watts as a basis of comparison is wrong then you really do not know what you are talking about? Watts is the basis of all comparisons of heat energy and power in industrial setting. Actually better still why dont you go up turlough hill and look at the stamps on the pumps, you will see watts.

Riven

The issue at hand is that we need to make the investments in renewable energy but the intermittent nature of these power sources means that the national grid can only accept a relatively small percentage of renewable power.

There is a worldwide search for storage systems that can allow for electrical power to be stored temporarily in periods of low demand and then use the power at peak demand periods. This will also allow the non renewable (ie in our case fossil fuel) plants to be run efficiently so that they are not running when wind power is not available.

Pumped storage was originally developed to be as you describe a 'load flattening device' but to many people represents the best and only technically viable storage solution to make renewable systems work and to allow the increase in their contribution up to the levels that are meaningful. To me it makes complete sense that a series of pumped storage installations are planned as part of the necessary infrastructure to create a workable system. Yes the process involves a certain waste and loss of energy but the gains outweigh this. At this point in time wind power is being generated which is of little real use as the ESB are still burning the same amount of coal, oil and gas in their central plant.

What we need is for somebody in the goverment, Eirgrid or ESB to take hold of what is required and with some imagination and proper engineering work the best solution for this country.

[feargach]

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

Watt hours = watts * hours.

Thanks, I know there is a time issue, and all of my posts bear that in mind. I know full well that Turlough hill can only output energy while there is still water remaining in its upper reservoir to turn the turbines. I never said otherwise. Believe it or not, I am entirely aware that Gandalf does not live on Turlough hill, every day using his magic to put an infinite unbroken supply of water into the reservoir.

So, DaveM, are you still avoiding the crucial issue? What is the going price of peak-time megawatt hours, per hour, to the UK grid?

If we have 500MW to sell to the UK grid every day, for two hours at peak-time, we can foresee with very good accuracy the range of prices we can expect to get for it. We can use this as the basis for seeing if there is a commercial case for building.

All we need is the price. You are asserting that there is no commercial case, which implies that the price range for peak-time electricity is too low to justify building.

Why then, do you evade telling us what you think that price range is?

I suspect that you have looked it up and discovered that the figure, in fact, does support the commercial case for PSH storage of wind turbine electricity (on the Swedish-Danish model currently existing right now, this very second).