Another wind generation record in Ireland

probe

At 16h45 today, the tiny handful of windmills installed, by the fortunate few whose owners have managed to get past the mountain of bureaucracy and vested interests preventing the growth of renewable energy enterprises, hit a new record of 1,053 MW of output.

Almost exactly one third of the electricity demand in the country (3,193 MW) was met by wind, on top of the non publicly disclosed hydro and other renewable sources of electricity.

If Ireland had 10, 20 or 100x this installed generation capacity in wind and other renewable kit, it would have a big export earner - as well as providing a large proportion of the domestic energy requirement.

Pharma, cloud computing/search engines and related businesses are large users of electricity. It will increasingly have to become green electricity, or else.....

Time Ireland put the Norwegians out of business in the Euro energy market

old boy

well if you live in county limerick you have no hope of getting planning permission for one, no more planning permission for them, infar south limerick one cannot get planning permission for a house, yet the co.council could spend 6m on a building for themselves in kilmallock,

SeanW

I'm not sure you noticed, but it was unusually windy yesterday. Around where I live, we never see any wind worth talking about unless the whole country is engulfed in a storm. And as you can imagine, it was rather windy here most of the day.

Your post just highlights - in as much as highlighting is required - that with weather-based renewables, we get not so much an electricity supply, but random alternating periods of feast and famine, with bumper 'harvests' such as yesterdays being rare exceptions. So each time a new peak is reached, you can make these "Another wind generation record in Ireland" threads until the end of eternity, it doesn't make a difference until we find a way to harnass and store these peaks. Preferably this method will A) not involve flooding 10% of the national landmass or not cause an increase in our already high electricity tariffs.

Additionally, (given that the grid controller needed to ensure that the grid continued running when the wind drops) how many baseline generators were turned off? My guess is a figure closly resembling zero.

Macha

SeanW wrote: »

Your post just highlights - in as much as highlighting is required - that with weather-based renewables, we get not so much an electricity supply, but random alternating periods of feast and famine, with bumper 'harvests' such as yesterdays being rare exceptions..

They are rare but impressive given our relatively small installed wind capacity. Once more is installed, including higher load factors with offshore, we will see higher and higher records as well as significant baseload contribution. There are also less variable and dispatchable renewables such as tidal and biofuels.

SeanW wrote: »

it doesn't make a difference until we find a way to harnass and store these peaks. Preferably this method will A) not involve flooding 10% of the national landmass or not cause an increase in our already high electricity tariffs.

I wouldn't say our renewables capacity doesn't make a difference but the variability will have to be addressed.

SeanW wrote: »

Additionally, (given that the grid controller needed to ensure that the grid continued running when the wind drops) how many baseline generators were turned off? My guess is a figure closly resembling zero.

That is the whole reason we have gas turbines - can you back up your guess that almost none were turned off?

zod

SeanW wrote: »

A) not involve flooding 10% of the national landmass or not cause an increase in our already high electricity tariffs.

Is this in reference to spirit of Ireland ? the reservoirs they propose flooding are steep glacial valleys, which would mean tiny amounts of land.

SeanW wrote: »

Additionally, (given that the grid controller needed to ensure that the grid continued running when the wind drops) how many baseline generators were turned off? My guess is a figure closly resembling zero.

I think you may be wrong. 60% of our electricity generation is from natural gas (source) , which afaik are ramped up and down easily.


Interested to know what your solutions might be ?

Grudaire

zod wrote: »

Interested to know what your solutions might be ?

Oh no - don't give him an open shot like this to derail a wind energy thread talking about the n-word!

Seriously though. The spirit of Ireland proposals seem too good to be true, but they seem to answer all questions quite well. Is it as good as it seems? and should we all be lobbying the government, and opposition to get it done?

zod

Cliste wrote: »

Seriously though. The spirit of Ireland proposals seem too good to be true, but they seem to answer all questions quite well. Is it as good as it seems? and should we all be lobbying the government, and opposition to get it done?

Wind power could easily power this small Island, it already provides 39% at times. source . We have the best wind resources in europe, at least twice as good as Germany who make 4 times more power from Wind then we need source. Germany employs 90,000 people in the wind energy sector.

The UK is a HUGE market for green energy and will get bigger as the need to cap CO2 increases.

The problem of wind variation can be solved by a Better Grid / Interconnectors ( it's ALWAYS blowing somewhere ) and by innovative energy storage. Hopefully SOIs numbers will prove correct and we can leverage a few glacial valleys, there is a huge amount of investigation into this at the moment. Whether it will provide enough for baseload or even export is another matter.

We spend billions every year on fossil fuel, making our own energy is a no brainer, at least the Germans seem to think so.

Grudaire

zod wrote: »

The problem of wind variation can be solved by a Better Grid / Interconnectors ( it's ALWAYS blowing somewhere ) and by innovative energy storage. Hopefully SOIs numbers will prove correct and we can leverage a few glacial valleys, there is a huge amount of investigation into this at the moment. Whether it will provide enough for baseload or even export is another matter.

Hmmm *Goes to read more!*

zod wrote: »

We spend billions every year on fossil fuel, making our own energy is a no brainer, at least the Germans seem to think so.

I was reading talk of the Germans maybe trying to push for Solar power in Africa to supply electricity up to them! (New Scientist)

zod

Cliste wrote: »

I was reading talk of the Germans maybe trying to push for Solar power in Africa to supply electricity up to them! (New Scientist)

A similar plan for wind energy in the states is called the "pickens plan" where the hope is to deliver electricity from a wind corridor that goes down the middle of the states and deliver it to the cities on the coast.

That distance is many times the length of Ireland.. makes you wonder why we think our distance is a big issue.

Heroditas

zod wrote: »

Hopefully SOIs numbers will prove correct and we can leverage a few glacial valleys, there is a huge amount of investigation into this at the moment. Whether it will provide enough for baseload or even export is another matter.

Their research has been discounted as being unfeasible and has been rubbished by those within the energy industry. This is not due to vested interests either - the idea is just a non-runner.

The ideal model is wind power backed up by small local peaking plants powered by bio-fuels or natural gas.
A vaguely similar system is used in Northern Ireland where if the load on the grid is too large, factories with genset equipment can power up and feed into the grid very quickly, thus bolstering the supply. These geneartors are mainly diesel-pwoered but it's the theory that's the important bit.

You can't really use the "traditional" power stations for such a system because they have to be kept "ticking over", i.e. they still consume relatively large amounts of gas, coal, oil in a standby mode so they can be ramped up to full generation capacity at a moment's notice.

Small localized peaking plants feeding into a wind-powered grid.
There's a system that can work.

SeanW

taconnol wrote: »

That is the whole reason we have gas turbines - can you back up your guess that almost none were turned off?

Err ... no. That's why I called it a guess.

zod wrote: »

Wind power could easily power this small Island, it already provides 39% at times. source . We have the best wind resources in europe, at least twice as good as Germany who make 4 times more power from Wind then we need source. Germany employs 90,000 people in the wind energy sector.

...

We spend billions every year on fossil fuel, making our own energy is a no brainer, at least the Germans seem to think so.

Cliste wrote: »

I was reading talk of the Germans maybe trying to push for Solar power in Africa to supply electricity up to them! (New Scientist)

Funny you both should mention Germany ...

Germany Plans Boom in Coal-Fired Power Plants -- Despite High Emissions
(Der Spiegel article)

Oh dear :eek: guess those windmills and 50c per kw/h solar panels aren't working as well as our eco-concious neighbors had hoped, seems you still have to have plenty of non-weather dependent baseline providers after all. Makes you wonder ...

limklad

zod wrote: »

A similar plan for wind energy in the states is called the "pickens plan" where the hope is to deliver electricity from a wind corridor that goes down the middle of the states and deliver it to the cities on the coast.

That distance is many times the length of Ireland.. makes you wonder why we think our distance is a big issue.

In the US doing big projects when money is involved is as easy as walking, They are well use to it.

Here in Ireland for Individuals to make small changes requires climbing Everest amounts of bureaucracy on every level of government and banks.

Grudaire

Heroditas wrote: »

Their research has been discounted as being unfeasible and has been rubbished by those within the energy industry. This is not due to vested interests either - the idea is just a non-runner.

O rly? Does one have a link?

SeanW wrote: »

Funny you both should mention Germany ...

Oh dear :eek: guess those windmills and 50c per kw/h solar panels aren't working as well as our eco-concious neighbors had hoped, seems you still have to have plenty of non-weather dependent baseline providers after all. Makes you wonder ...

A 2007 article? nothing more recent? It's probably somewhere between what we all make out...

:eek: :P

Heroditas

Cliste wrote: »

O rly? Does one have a link?

Nope but from talking to the policy makers in the major utilities they say it's a non-runner. Oh and before you accuse them of being tied to fossil-fuels, these guys are committed to harnessing as much green energy as possible and expanding Ireland's renewable portfolio.
They just don't think this option is a feasible one

Grudaire

Heroditas wrote: »

Nope but from talking to the policy makers in the major utilities they say it's a non-runner. Oh and before you accuse them of being tied to fossil-fuels, these guys are committed to harnessing as much green energy as possible and expanding Ireland's renewable portfolio.
They just don't think this option is a feasible one

Eh....

To be honest I'm more likely to accuse you of talking through your arse.

Which to be fair is exactly what it looks like. Now I can imagine problems with any energy production plan, so surely you can come up with better than that?

Heroditas

Why would I lie? I have nothing to gain by doing so.

Even if you carry out back-of-the-envelope calculations for the SoI scheme, the numbers don't add up.

Grudaire

Heroditas wrote: »

Why would I lie? I have nothing to gain by doing so.

You're anonymous on-line, to be honest you could be the CEO of Shell, and for all I care you could even be a politician.

I try and deal with facts...

Heroditas wrote: »

Even if you carry out back-of-the-envelope calculations for the SoI scheme, the numbers don't add up.

I try to learn about stuff - educate myself if you will.

On this thread I am talking to a wall - so far. I'll approach anything that is put in front of me with an open mind, heck I doubt the SOI proposal is the whole answer to the problem, but it seems like a damn good proposal. And in their forum they seem to be answering the questions that are put up against the project...

Heroditas

SOI made a huge issue out of the lower price of the electricity they would produce and the possibility for export.

The proposal mentions generating revenue of 2.6billion per annum based on a 2 GW output. Based on a 24/7 output that equates to 17,520 GW Hours or 17,520,000MW hours generating 2.6 billion in revenue over a year.

or €148 per MW hour which is very expensive. This is over three times the current UK wholesale price of electricity.

That's for starters anyway!
I'll post some more tomorrow with a bit more of my opinion on it.

Grudaire

Heroditas wrote: »

SOI made a huge issue out of the lower price of the electricity they would produce and the possibility for export.

The proposal mentions generating revenue of 2.6billion per annum based on a 2 GW output. Based on a 24/7 output that equates to 17,520 GW Hours or 17,520,000MW hours generating 2.6 billion in revenue over a year.

or €148 per MW hour which is very expensive. This is over three times the current UK wholesale price of electricity.

The figures that they are working off to quote 2.6b (or 5bn in one of their reports) elude me. We are limited by the inter connector at the moment isn't that the case?

Heroditas wrote: »

That's for starters anyway!
I'll post some more tomorrow with a bit more of my opinion on it.

I look forward to it (hope I have time to check boards tomorrow now!)

SeanW

Cliste wrote: »

A 2007 article? nothing more recent? It's probably somewhere between what we all make out...

:eek: :P

Right so, lets see ... little change in the nuclear power phase out, the new load of coal-fired power plants still have the green light, a few more in the endless line of tweaks to a renewables policy that will, in due course, amount to sweet F.A. Hence all the new coal-fired power plants.

No real changes since 2007. My article thusly remains substantively relevant.

Shiny

We need (LOADS) more storage, whether that be from the Spirit of Ireland proposal or from someone other initiative.

This will negate the need for peaking plants/conventional plants to cover
the ass of wind generation.

I used to be a big fan of the flow battery but these things are nowhere near
the scale that is needed to supply the country.

Grudaire

SeanW wrote: »

Right so, lets see ... little change in the nuclear power phase out, the new load of coal-fired power plants still have the green light, a few more in the endless line of tweaks to a renewables policy that will, in due course, amount to sweet F.A. Hence all the new coal-fired power plants.

No real changes since 2007. My article thusly remains substantively relevant.

No, I think you're looking at it as if renewables are not going to be used, I get the opinion that they're building coal for a guaranteed base load, to replace the even dirtier old coal powered plants. (From your article). Problems regarding reliability of supply in relation to renewable energy is common.

It does make you wonder. But Renewable energy is still being developed fully.

Wikipedia wrote:

Since 1997, Germany and the other states of the European Union have been working towards a target of 12% renewable energy electricity by 2010. This target was surpassed already in 2007 when the renewable energy share in electricity consumption in Germany reached 14%.

Germany to aim for 45% renewable by 2030

carveone

Cliste wrote: »

It does make you wonder. But Renewable energy is still being developed fully.

It's a hell of a good way of creating (certain types of) jobs, that's for sure.

Still, I was chatting to an Engineer who worked in Poolbeg. He said the combined cycle gas plant there is very efficient at 54%. Compare to a gas turbine at 36%.

You can't back up a quickly varying system like wind power with a plant like Poolbeg. You need to use gas turbines and to use a lot of them given the aggressive spool up-spool down cycling taking some of them out of commission for maintenance. You're probably hammering the crap out of the natural gas network as well. Plus all this gas comes from Russia. I don't really see that as a good thing.

Take the differences in efficiencies and calculate whether wind is making up the difference. I don't think so. On the other hand take the difference between my brother's insulated 2000 era house and my parent's barely insulated 1960s era house and you see major differences in energy usage.

Oh well... Whenever governments get involved with subsidies, Bad Things happen. For two reasons: Governments are dumb and Corporates see the huge feeding trough and can't help putting their snout in. Still. Wind is better than Biofuels which were an appalling nightmare.

probe

1. Most of the existing installed base of gas, coal, hydro and other “traditional” electricity generation plant in Ireland will remain operational into the future. Many of the anti-renewable postings in this forum appear to have an underlying assumption that someone waves a magic want, and all the legacy kit is no more, leaving the country at the mercy of wind variability etc.

Much of the legacy kit is fully or largely depreciated in accounting terms – its main operating cost is fuel and labour so the real cost per kWh generated is relatively low in terms of its ability to compete in a market where prices vary by large factors.

2. Avoiding blackouts in a new renewable environment - anyone in the industry installing new carbon based generation kit (eg natural gas based) should be thinking about peaking plant. This is generating plant that can start generating within 5 or 10 minutes of pressing the button. Nuclear takes days to get going by way of contrast, and is therefore useless in the context of matching the spikes of wind, solar and other natural energy sources. The fastest responding plant to provide electricity “on the button” is probably pumped storage (perhaps 1 minute delay). Capacitor based storage could respond in milliseconds, assuming it was under automated command. Where capacitors are dispersed (eg in people’s cars or homes) the response time would probably be longer. A geographically dispersed wind plant system is not subject to sudden, dramatic falls or increases in generated output. Ireland’s current wind generation plant is concentrated in a few locations – which is unhelpful in the scheme of things.

3. A country needs enough interconnector capacity + storage + on demand capacity to meet all electricity demand needs. On-demand capacity can include legacy plant, peaking plant, and bio fuelled plant (wood, algae, etc). It is conceivable that existing oil powered generation plant could be modified to run on algae or other bio fuels. [Incinerators can also be used to generate electricity, but they are more efficient if used as part of district heating systems located close to where people live and work (and generate the material to feed them)].

Large bursts of surplus energy can also be stored using sea-water pumped storage systems. (See http://www.greenpowerisland.dk/greenpowerisland.pdf for a Danish example, which can store up to 35,000 MWh each). I see these as a solution to storing surplus energy, rather than being something one can rely on to keep away from blackouts in extremely calm weather which might last for several weeks. Long periods of calm weather require a combination of interconnectors, legacy plant, peaking plant, and bio fuelled plant (as well as getting some respite from storage. (If you had an extreme case of two weeks of zero wind blowing (virtually impossible in reality), and total reliance of wind energy, no interconnectors, in the peak period of demand just coming up to Christmas, you would need about 35 storage units of 35,000 MWh each).

4. There needs to be end to end market pricing transparency and flexibility for the full range of renewable technologies to develop their maximum potential – this includes smart metering, and a flexible supply market where the cheapest producer can “dump” output – forcing the more expensive producer to go offline or reduce its price.

An example might make this clearer.

In 201Y, Mr X takes delivery of an electric car and lives in a country that has smart metering and transparent variable pricing down to consumer level. On windy nights, Mr X can buy electricity for 4c per kWh, because the wind industry is producing far more electricity than the country requires or can otherwise use. He needs 50km of stored electricity range in the car for tomorrow to cover his 10 km drive to/from work, and to allow for unforeseen delays and diversions. He can store 400 km of electricity in the car – so when the price falls to 4c per kWh, his smart charger is programmed to “tank up”. It stops charging when the battery is full or the price exceeds 7c – (if it has past the required minimum of 50 km of power).

Mr X can decide to keep this electricity for driving, or if he doesn’t need it, he can sell the stored power back into the grid if the market price exceeds a given level which he decides on. A country with a national grid made up of thousands of Mr Xs has a vast storage resource, dispersed all over making maximum use of the existing network in both directions, reducing the risk of any single point of failure in the system.

During the conference call with Zenn investors in June 2009, CEO of EEstor Dick Weir said that he was able to produce storage capacitors for about $100 per kWh of storage*. Car based storage has the benefit of wide dispersion, an incentive to people to upgrade to electric personal transport, and offers the option of meeting a large proportion of their domestic electricity needs from cheap surplus electricity. A spare €3,000 ultra capacitor in the garage would allow the householder to store 30 kW of electricity – which is enough for a day or two in an average household – and provide backup “fuel” for long journeys in the e-car. (Not that it would be necessary thanks to the quick charging ability of capacitors – but the fuel would be cheaper compared with a motorway filling station).

Green Power Island storage: www.greenpowerisland.dk

*EEstor investor interview: http://www.4all.com/uploads/DW_Confcall_jun2009.mp3

Heroditas

Cliste wrote: »

I look forward to it (hope I have time to check boards tomorrow now!)

Sorry for the lateness is replying.
Here's a post by someone elsewhere that explains some of the maths behind this:

You have a 10 MW average demand with a peak demand of 15MW. It decides that it will provide this 10MW demand using a combination of wind and pumped hydro.

So it builds reservoirs to provide 48 hours of backup and 10MW of wind capacity using 100 wind turbines

All goes to plan the reservoir is full and everything is in place. The wind turbines are generating 10MW quite happily until the wind fails in an area for say 6 hours and 3 turbines or 3MW is lost. Start up the pumped Hydro plant to meet the demand and then the wind pick up again.
Now 3MW for 6 hours means 18MW hours of capacity have been removed from the "battery".

To refill this will require require 18 wind turbines running for 6 hours. Except there are losses of say 50%. So now it will take 18 turbines 12 hours or 36 6 hours to replace the lost capacity. But that's OK because by night the demand drops by 40% to 6 MW for 8 hours. So that night the extra 4 MW can be used for 8 hours to refill the "battery".

But hang on 4 MW X 8 hours is 32MW hours or a shortage of 4 MW.

Now that's assuming that for 18 hours out of 24 the turbines were running at 100% capacity and 100% efficency which will never happen. You need to build in extra generation capacity to allow for the fact that at no time will you have 100% capacity from your wind turbines. Then you have to build in extra capacity to refill the battery when needed. The lower your efficiency the more extra capacity is required.

With 50% efficiency if you plan on replenishing the battery at the same speed at which you drained it then you need to have extra wind power capacity of twice the generation capacity of that particular pumped hydro plant.

Its unlikely you will be using all your hydro plants at the same time but lets say 30% of your daily power comes from pumped Hydro then you would need to build wind generation capacity to meet your proposed supply level. Plus an allowance for certain levels if wind fluctuation plus and additional 60% to cover the requirement to re fill your battery.

So that would be 10MW plus which at 20% efficency woudl require 50MW generation capacity to allow for fluctuations in wind and 30MW to refill the battery.

So for a 10MW supply you would need to build 80MW of wind generation capacity. Drop your efficiency and that figure gets worse.

You can also decrease that figure by taking longer to refill the battery (say for each 4 hours drawn out take 8 to put it back) but that would require you to build even more storage capacity.

They have stated that they will make 2.6bn per annum from two reservoirs. Those numbers don't stack up.

I can't believe that you can "dam" a costal valley, seal it fully and install turbines that will displace enough water to provide an adequate storage capacity. We're talking millions of tons of water. I wonder at how efficient a pump can possibly be as the reservoir starts to fill up.
We would also have to seal the walls of the artificial reservoir to ensure salt water doesn't work its way into the water table. Imagine doing this for a whole valley? Imagine a whole valley full of stagnant sea-water waiting to be released? How will this be overcome?

I like the idea. I'm an engineer and it shows great initiative. Unfortunately I don't think it's a runner and the SoI guys aren't exactly helping their cause by releasing statements before then rowing back and saying "actually, what we meant to say is...."
That may work in academic circles but not in industry.

I'm strongly in agreement with what Probe advocates - peaking plants that can be started up at a moment's notice. The system is already used in Northern Ireland to make up any deficit by getting industry to fire up their generators to support the grid. They may be dirty diesel gennies but the core idea is the same.
Imagine a smart grid consisiting of local community CHP plants, wind farms off the west coast and then bio-fuel/biomass/incinerator style peaking plants. I think that could work.
If we could also improve the efficiency of the peat burning plants we could get further down the road towards energy independence. (Peat ain't good for the old CO2 emmissions though!)

Grudaire

Heroditas wrote: »

Sorry for the lateness is replying.
Here's a post by someone elsewhere that explains some of the maths behind this:

That is a terribly confusing Mathematical argument. If I could see the whole argument (I assume this is from a forum [p.ie or SOI's forum?]) I might be able to make better sense of it?

But the figures are a bit haphazard, and in many ways simplistic (Yes I know, simplistic is an odd word to use looking at that jumble). To be honest whoever is looking at this should probably be using differential equations, and I'll explain why:

If we use 30% hydro in a day, we need 60% extra power production, but if we add 60% to power production, working at 70% (as per example), then we won't need 30% hydro in the day... right?

I'm also a bit confused about the 20% efficiency coming out of nowhere..

Not to mention that it doesn't factor in other potential sources of power (See probe, or think of the interconnector)

Heroditas wrote: »

They have stated that they will make 2.6bn per annum from two reservoirs. Those numbers don't stack up.

I can't believe that you can "dam" a costal valley, seal it fully and install turbines that will displace enough water to provide an adequate storage capacity. We're talking millions of tons of water. I wonder at how efficient a pump can possibly be as the reservoir starts to fill up.
We would also have to seal the walls of the artificial reservoir to ensure salt water doesn't work its way into the water table. Imagine doing this for a whole valley? Imagine a whole valley full of stagnant sea-water waiting to be released? How will this be overcome?

I like the idea. I'm an engineer and it shows great initiative. Unfortunately I don't think it's a runner and the SoI guys aren't exactly helping their cause by releasing statements before then rowing back and saying "actually, what we meant to say is...."
That may work in academic circles but not in industry.

I'm strongly in agreement with what Probe advocates - peaking plants that can be started up at a moment's notice. The system is already used in Northern Ireland to make up any deficit by getting industry to fire up their generators to support the grid. They may be dirty diesel gennies but the core idea is the same.
Imagine a smart grid consisiting of local community CHP plants, wind farms off the west coast and then bio-fuel/biomass/incinerator style peaking plants. I think that could work.
If we could also improve the efficiency of the peat burning plants we could get further down the road towards energy independence. (Peat ain't good for the old CO2 emmissions though!)

I'm a bit confused about the 2.6bn, but I think there's lots questionable about that - starting with an interconnector that can't deal with that much load.

I can only deal with the numbers, I can't venture a guess on the engineering problems. I have a bit of faith that you and your kind can answer the questions you are posing at the end there!

Heroditas

The argument is a bit confusing alright.
I see your point aboutdifferential equations being needed.
The point about pumped hydro storage is that you put an awful lot more energy in than you wil get out and because of pump efficiencies, this increases the amount of energy you put in.
If you are using the hydro power one day, you still need to refill the reservior but at the same time you also need to be supplying the country with power. Therefore you need more wind turbines. Also, if the wind doesn't blow for a period of a few days, you could be left with an empty reservior!

The interconnector between Ireland and Wales will be 400MW - i.e. roughly equivalent in size to one of the power stations in Huntstown.
Yes it does limit what can be exported but they do not appear to have taken that into account in their maths where they state they can export billions of € in electricity every year.
They've come up with a simplisitc figure of an excess of power and stated that it can be sold (at a massive premium) but they have not shown how it can actually be exported.

The argument does indeed come from p.ie's environmental section.
Beware though, the thread is over 100 pages long! :eek:

Grudaire

Is hydro not one of the most efficient forms of energy storage?

He's throwing around numbers, but it's basically wrong. I hope this is what convinced you that SOI isn't worthwhile! Like the 20% argument is all over the place as well. Assumedly we will get ~ 1MW from a 1MW generator a good chunk of the time, so why are we dealing with 20% efficiency as a standard (If you're catering for filling up the resevoirs at 20% efficiency I'd just change the alleged capacity of the windmills) surely we can allow for the resevoirs to go down a bit when there's no wind!


I assume that there would be more wind production than is used - but is this not factored in by SOI?

Heroditas

The numbers that I quoted are quite simplistic but they make more sense than the very basic numbers that SoI quote.

Here's my own basic maths.
To be "guaranteed" 1MW of power, you ideally need 3MW of wind turbines. That is the accepted figure.
Now, you have 1MW of power and you then need to fill a reservoir using pumps. You have to take transmission losses into account for the power as it travels to the pump and then you have the pump's efficiency of, say, 85% - this leaves us with about 0.8MW of power that has been transferred to the reservoir.
So we have 3MW of wind and this gives us 0.8MW of hydro.
Remember, if you're filling the reservoir, you need more wind turbines to fuel the grid for the users!
Also, it can be quite common for the wind to drop for sustained periods of time. What happens then if the reservoir is empty? It's almost a double jeopardy.

Transform these figures into figures that we need for Ireland to be energy independent - we need about 6GW of hydro power. That would result in us needing 22.5GW of wind just to ensure you have enough constant coverage of wind to simply fill the reservoir as quickly as possible.
Then you need more wind turbines to supply electricity to the country while the reservoir is being filled! I've taken peak demand here and increased it a bit to take into account further growth in the electricity market.

Of course, you can use alternative sources such as the interconnector to import power to fill the reservoir but that defeats the whole concept of "energy independence".

SoI is a classic example of the law of diminishing returns. However, this time it's on a vast scale.
Some small ones like Turlough Hill may be viable but doing it on a national scale using existing technology? I don't think so.

zod

Heroditas wrote: »

I can't believe that you can "dam" a costal valley, seal it fully and install turbines that will displace enough water to provide an adequate storage capacity. We're talking millions of tons of water. I wonder at how efficient a pump can possibly be as the reservoir starts to fill up.

approximately 70% to 85% of the electrical energy used to pump the water into the elevated reservoir can be regained. source

Heroditas wrote: »

We would also have to seal the walls of the artificial reservoir to ensure salt water doesn't work its way into the water table. Imagine doing this for a whole valley? Imagine a whole valley full of stagnant sea-water waiting to be released? How will this be overcome?

They seemed to have worked through any issues in Japan :

Heroditas

zod wrote: »

approximately 70% to 85% of the electrical energy used to pump the water into the elevated reservoir can be regained. source

I was working with a figure of 85% in my last post so that's a best-case figure. OK cool.

zod wrote: »

They seemed to have worked through any issues in Japan :

That's a very small scale model compared to what SoI are suggesting and is more comparable in scale to Turlough Hill