Cost of electricity from Wind.

Mailman

Anyone know the cost to generate kWh of electricity from offshore wind farm in Ireland vis-a-vis Gas turbine power station?

Surely, wind must be closing in on Gas at this stage.
Gas just keeps going up in price and wind turbines keep getting more efficient.

meditraitor

This is a tricky one as wind energy costs cannot be easily calculated. The cost of wind energy is directly related to the average wind speed and size of the wind farm, small differences in average windspeed from site to site can have significant effects on the production of energy therefore its costs.
Larger wind farms provide economies of scale.
Wind energy is a highly capital-intensive technology; its cost reflects the capital required for equipment manufacturing and plant construction. This means that the economics of wind/energy supply are very sensitive to interest rates on initial capital.
if environmental costs were included in the calculation of the costs of electricity generation, wind energy's competitiveness will increase because of its low environmental impacts.
I dont believe(not aware) any proper studies within Ireland have been carried out that could comfortably answer your question as the comparison would be too hard to make at the moment.

air

Wind turbines are pretty much as efficient now as they are ever going to be, they are within a hairs breath of the theoretical maximum energy extraction.
As meditraitor says it's a complex issue, as well as everything he/she mentioned you have issues like availability to consider as well.

Mailman

Yes, but costs of turbines are coming down and if the government guaranteed a market for their electricity then the cost of financing the project would be less as there would be less risks associated and lower interest rates on loans bringing down the cost per KWh to a point where it is competitive with Gas.

meditraitor

Mailman wrote:

Yes, but costs of turbines are coming down and if the government guaranteed a market for their electricity then the cost of financing the project would be less as there would be less risks associated and lower interest rates on loans bringing down the cost per KWh to a point where it is competitive with Gas.

You might find this interesting

http://www.ucc.ie/civileng/staff/brian/EWEC04SP.pdf

And some info here also,,

http://www.iwea.com/windenergy/maptablewindfarms.pdf

Mailman

thanks, I'll look through it, not light reading.

spooiirt!!

For every MW produced by wind facilities, 0.85 MW from conventionel sources have to be constantly ready to take over in cases of wind levels falling, or storms ( during which Wind turbines have to be shut down afaik).

In germany we currently have 6 conventional power plants constantly burning fossil fuels to keep pressure levels high so that they can immediatly take over electricity production when the windmills stop. Thats pretty darn expensive, and does little to stop Co2 emissions, as the fossil fuels are burned anyway, but the burning of these fossil fuels isnt used to produce energy, it used to keep the plants ready. Which theoretically means that there is no reason for us to have the windmills. Except maybe to get money from the EU. But then again Germany is the top contributor to the EU...

zod

spooiirt!! wrote:

For every MW produced by wind facilities, 0.85 MW from conventionel sources have to be constantly ready to take over in cases of wind levels falling

This sounds very high (85%).. excuse my ignorance but do you have any internet sources to back this up ?

If it's true then there is no point IMO

spooiirt!!

I do, but its in German. some science website...

http://www.buerger-fuer-technik.de/argumente.html

haha its a bit crap, cos you probably dont speak german... so il quote and translate for you:

"Für 1 MW Windenergie müssen 0,85 MW konventionelle Energie in Reserve bereitstehen "

For every MW produced by wind facilities, 0.85 MW from conventionel sources have to be constantly ready.


"Echte Herstellkosten Solarstrom: min 0,40 €/kWh
Strom aus Braunkohle, Kernenergie: 0,02 €/kWh "



Cost of one kwh Solar energy 40 cent, cost of coal/ nukuler energy o.o2 cent per kwh.
I assume kwh is a basic unit of measuring electricity, maybe Kilo watt hour".
No idea. Still its pretty expensive.


What ive read on the subject ( mostly in newspapers and the internet, as well as one book about what our state wastes money on), has told me that wind energy is essentially pointless, as it has to be constantly backed up because wind levels are hard to predict, and obviously when theres no wind, theres no power. The problem is that you cannot just flick on your coal/nuclear plants, and have them take over as soon as the windmills stop, because they have to build up steam to produce energy, and that takes a few hours. Hence the 6 stations we have here burning day and night.

zod

0.85 MW from conventionel sources have to be constantly ready

I think although I may be wrong .. that 85% of capacity has to be ready, the standby generators must be idling, not producing energy and dumping it ( where would the dump it )

If it was the case surely they could throw the unused energy into more productive things like , pumping water up a hill for later use, creating hydrogen from water electrolysis, or winding up kinetic wheels etc

spooiirt!!

What they do is burn the coal/gas etc, build up the steam, and maintain the steam pressure. That steam is not used for energy production. Its just there to be ready for the drop in wind. The 85% refers to the fact that the conventional power stations run at 85% efficiency in order to maintain pressure.

"If it was the case surely they could throw the unused energy into more productive things like , pumping water up a hill for later use, creating hydrogen from water electrolysis, or winding up kinetic wheels etc"

They dont actually produce electricity, they simply produce steam, so that they are ready to produce electricity at any moment.The point is that wind could stop at any moment, so the coal stations have to be ready 24/7.

air

That is the benefit of increasing the size of your electricity grid, it allows you to balance wind with wind.
As you increase the geographical area the chances of all areas being without wind reduces and this then allows for a reduction in the backing capacity required.
There are allternatives to fossil fuel backup also. Turlough Hill power station for example can either pump water up (taking up excess capacity in the grid) or let it down (to generate electricity). Its response time is very fast (I can find out the exact figures if you want) and it doesnt use any fossils. The great thing about this type of setup is that if it's capacity is say 200MW, it has the scope to have a 400MW impact on the grid (+/- 200).
Unfortunately the lack of naturally suitable sites means that you cant have too many of them without prohibitive civils costs.

spooiirt!!

air wrote:

As you increase the geographical area the chances of all areas being without wind reduces and this then allows for a reduction in the backing capacity required.
.

Wether the chances of wind dropping are say 25%, or 10 % has no effect on the amount of backing capacity required.
If the state needs to have 10 million KWhs ready when there is a 25% chance of wind dying, it will still need 10 million Kwhs if there is only a 10% chance of wind dropping. Probability of wind loss has no effect on result of wind loss.
It doesnt matter if there are windmills everywhere, they still all need to be backed up. Because they all stop regularly.


"and it doesnt use any fossils."

How much does it cost comparde to fossil fuels? how much electricity does Turlough produce? Would it be enough to back up a windmill for a day or so?

air

spooiirt!! wrote:

Because they all stop regularly.

But they dont stop at the same time.
You missed my point completely.
My point was that if you increase the geographic distribution of your wind generation you decrease the possibility it being calm at all the locations all the time.

Take this simple analogy.
Say you have two windmills.
Say the probability of calm weather is 0.5

Case 1:
You put the two windmills side by side.
Probability of it being calm at location of both = 0.5

Case 2:
You put the two windmills in two locations which are geographically seperated enough to ensure that their probabilities of being in calm weather are unrelated - EG put one in Ireland, the other in Germany
Probability of being calm at location of both windmills = 0.5 * 0.5 = 0.25


Case two is designed to highlight how increased geographic distribution benefits the overall availability of wind.

spooiirt!! wrote:

Would it be enough to back up a windmill for a day or so?

At 292MW it could back up Irelands entire wind generation capacity.

spooiirt!!

No, no, i understood your point alright man. However, even if the chance of both windmills stopping at the same time is 0.25, what happens when both do stop? Despite this being less likely than if there is less windmills, its still possible. And even if only one stops, it still needs to be backed up, because we arent able to predict which Windmill will cease and at what time, or indeed how many will stop.


"EG put one in Ireland, the other in Germany"


As much as i am in favour of co-operation between our two countries, the problem is that the further the plant is away from the town it "feeds", the more energy is lost along the way. This adds to the expenses of our hypothetical two windmills.

"At 292MW it could back up Irelands entire wind generation capacity"

Ok. But for how long? Long enough for a day or two i.e. how much time is needed to build up pressure in coal/gas etc plants?
Also, if we build more windmills, and therefore rely more on wind, will it be able to meet the added demand when wind levels fall? Do we have the ability to build more stations like Turlough? Is there enough suitable rivers in Ireland to back up wind energy if we were to build more windmills? What would the construction of more windmills plus more Turloughesque power stations cost? How would these expenses compare to the use of conventional energy sources?

p.s. lotsa questions, i know. sorry

air

OK, you did understand me then
What I was trying to say really was that by geographically dispersing the windmills you greatly reduce odds of them being stopped and thus you can reduce your backup ratio.
IE. you would obviously need full backup capacity in case 1 but for case 2 you could afford to reduce the capacity slightly, its a trade off.

With regard to transmission losses, I'm afraid that interconnectors and long distant transport of electricity are a fact of life completely independent of green energy. We are already doing this for reasons of grid stability etc.

A day would be more than enough to run up a gas station.

I can get the exact run up times of any station in the country if you like.

I'm not advocating a totally wind powered country (for the reasons you mention in your last paragraph). I would merely suggest that the proportion of our energy production that comes from wind should be increased at least to a level at which the regulation becomes an issue

The only reason that wind causes any problems at all at present is because we are so tight for supply. If we had say 15% extra capacity in the system (as we should) then having 15% of our production coming from wind would be no problem.

With regard to Turloughesque stations, I'm sure we could build one or two more somewhere and we could also diversify more into wave / PV in order to further immunise ourselves from variations in supply.
<rant>
Slightly OT but I strongly believe that the large number of people living in one off housing in Ireland in rural areas should be totally off grid and running on combined wind / solar systems. For about 10-12K one could put in a wind / solar system that would harvest a good 10Kw a day which should be more than enough for a household.
Our main problem is the way we squander energy at present. Using electricity to heat anything (bar maybe the kettle) should be outlawed IMO! </rant>

spooiirt!!

air wrote:

OK, you did understand me then
What I was trying to say really was that by geographically dispersing the windmills you greatly reduce odds of them being stopped and thus you can reduce your backup ratio.
IE. you would obviously need full backup capacity in case 1 but for case 2 you could afford to reduce the capacity slightly, its a trade off.

How can having a smaller chance of complete loss of wind power mean that there is less need for backup capacity? Thats like saying " you are unlikely to break both your legs, so you need only insure one". What if both legs break? Remember your idea about a windmill in IRL and one in GER:
(This is from an earlier post of yours):

"But they dont stop at the same time.
You missed my point completely. "

Is there some sort of law of physics that prevents Germany and Ireland having wind droughts at the same time? How can you say "they dont stop at the same time"? Its less likely the more windstations we have that we need to replace ALL of them in times of wind drought, but its still possible.


"A day would be more than enough to run up a gas station."

So we have a wind mill that needs to be built, a water station that backs up the windmill for just enough time , and a gas plant that then takes over. So essentially we have three power plants that have to be maintained and waited on by expert personel, where we could just have a gas station.

air

I should have said "they are less likely to stop at the same time".
I made a gross simplification to make a point and you're being a bit pedantic about it now.

The idea would be that you have a network of windmills spread over a very large geographic area networked together by a common grid. Your network should also have components of solar, wave, hydro etc etc - ie other renewable energy sources.
The idea is that you have a diverse enough source of power that you can improve the quality of supply.

spooiirt wrote:

So we have a wind mill that needs to be built, a water station that backs up the windmill for just enough time , and a gas plant that then takes over. So essentially we have three power plants that have to be maintained and waited on by expert personel, where we could just have a gas station.

As I've mentioned already we have the water station already, I'm not sure how long it can run but I'd guess it's a lot more than one day.

How many expert personnel wait on each windmill?

Do you honestly think that burning a finite fuel source is a long term solution to energy supply? Stop and think for a minute about how long humans have been on earth and then think about how long we've been consuming natural resources really heavily (~100 years).
Oil supply is already becoming tight, where do you think we will get our oil / gas in 3 - 5 hundred years time?
Even if the world's population stabilises now & everyone in it becomes a consumer we're looking at at least a 4 fold increase in energy usage above what we have now unless we economise.

Renewables arent a simple solution, but energy supply is not a simple problem either.

Finally, what point is it that you are trying to make exactly?
My own is merely that by diversifying the locations of wind production you can reduce the backup factor.

Your point about backing up 100% of wind on the of the time simply isnt how the world works.
For example telephone networks can't cope if everyone makes a call at the same time, airlines overbook seats based on the probabilities of people not turning up and power companies guarantee a certain maximum import capacity to customers even though they know they can't meet everyone's concurrently.

Capt'n Midnight

spooiirt!! wrote:

For every MW produced by wind facilities, 0.85 MW from conventionel sources have to be constantly ready to take over in cases of wind levels falling, or storms ....

In germany we currently have 6 conventional power plants constantly burning fossil fuels to keep pressure levels high

The north of Germany is kinda flat. But here most of the population is resonably near large hills and sources of water are not a major problem. This is what the ESB started back in 1968.
http://www.esb.ie/main/about_esb/history_turlough.jsp
http://en.wikipedia.org/wiki/Turlough_Hill
The technology we need to store wind power has been in use for over three decades.

spooiirt!!

air wrote:

Finally, what point is it that you are trying to make exactly?
My own is merely that by diversifying the locations of wind production you can reduce the backup factor.

Simply because there is more windmills doesnt mean that they cannot all fail.
Simply because they are spread everywhere doesnt mean they cannot all fail.
What if 80% of them arent getting enough wind? or 70% etc? How many of them do you propose we back up?
Wind turbines only start to operate when the windspeed reaches 18km/hour (5 metres/sec, moderate breeze, force 4), and have to be switched off ( otherwise they simply break) when it reaches about 85 km/hour(23 metres /sec, storm force 10). Between these limits a turbine's output varies according to the windspeed turn .

What if you have a very high wind in southern Ireland and a serious drop in wind in Northern Ireland?
Will parts of Ireland just stop working for a day or so?


"My own is merely that by diversifying the locations of wind production you can reduce the backup factor."

My point is you cant. The more windmills you have, the more windmills have to be backed up.


P.s. The two biggest wind "farms" in Europe are in Powys, at Llandinam and Carno. Between them, they have 159 turbines and cover thousands of acres. Together they take a year to produce less than four days' output from a single 2000 MW conventional power station. Together, they have an output averaging 20 MW (in winter, UK demand peaks at about 53,000 MW.

air

I'm not arguing with anything that you're saying, all I'm trying to say is that the statistical probability of the weather being calm across a very large area is low enough that the power utilities would likely take the chance and use less than a 100% back up factor. This would be in line with the other examples that i've stated above.

I'm sure your figures on the gas vs farms are spot on but that doesnt take away from the fact that gas is a finite resource that will not last forever, wind (like all solar energy) for all intents and purposes is a limitless resource.

Keeks

spooiirt!! wrote:

P.s. The two biggest wind "farms" in Europe are in Powys, at Llandinam and Carno. Between them, they have 159 turbines and cover thousands of acres. Together they take a year to produce less than four days' output from a single 2000 MW conventional power station. Together, they have an output averaging 20 MW (in winter, UK demand peaks at about 53,000 MW.

I like the fact that you have quoted two of the "smallest" windfarms currently around by todays standards. The windfarm at Llandinam is now 13 years old and consist of 113 300kW turbines with a maximum capacity of 30.9MW. The windfarm at Carno is newer but still 10 years old. It consists of 56 600kW machines.

Just for comparsion there is a 10 turbine site at Kingsmountin consiting of 10 2.5MW turbines with a maximum capacity of 25MW.

Just beacuse they have the most turbines doesn't mean it is the biggest wind farm around. In the power generation industry, the biggest generally measn the maximum a site can produce.

As for talking about "What happens when the wind stops", it generally doesn't. Wind turbines in Ireland are producing electricty over 90% of the time. The other 10% of non-producing time is mad up of servicing, low windspeed (less that 4m/s) and high wind speed (greater than 25m/s).

I think if you focused you're arguments arounf "How much" enegy these windfarms produce and how they are managed by the national grid you could see there benefits.

Capt'n Midnight

Electricity demand is even spikier than wind power. And as for having standby power what about the Gas Power station they had in the UK that was only used at 7:30 on Wednesday evenings ?

Tourlough Hill can go from 0 to 250MW in 60 seconds. And if you didn't mind taking a hit on efficiency you could use the windmills to pump water. Pumps being a lot cheaper than generators.

Another option is wave power, it's a little more even than wind power.
Tidal turbines along the East and South-East coast would be interesting due to the way tides work in the Irish Sea.

Anyone got the costs on Carbon emissions, how much per year would the carbon-tax be per unit ?

spooiirt!!

So in Ireland wind farms only stop 10% of the time? Can i see sources if you have em handy? If they stop ten percent of the time, we still dont know when they stop. So they still need to be backed up constantly, as out of every ten days, they can stop one day.

So can Turlough produce these 290 MW every day?

Capt'n Midnight

spooiirt!! wrote:

So can Turlough produce these 290 MW every day?

I'd doubt that it could produce even 1MW continuously unless there is a monster of a rain storm. It STORES energy, it does not produce it. It is a complementary technology to wind. CBA looking up the total storage of Turlough hill as almost any current hydro plant could be retro fitted to pumped storage once there is a basin of water near the bottom of the DAM. Doing that would also increase the levels of Roundwood and Blessington Resevoirs too, so there are other fringe benefits

ESB MEASURED fluctions in wind power on Irish Wind Farms.
http://www.ee.qub.ac.uk/blowing/activity/Dublin/main.htm
http://www.ee.qub.ac.uk/blowing/activity/Dublin/r_costello.pdf - see Page 16

Variability Studies
· Hourly swings - first 6 months of 1999, 2000 and 2001

· once per day expect swings > 15% capacity
· once per week > 20%
· once per month > 30%
· no swings > 50% over 1 hour period

Of course wind power is not the total solution, but with an interconnector to UK and hence to France one weather system could power windmills over several hundred Km as it tracks across countries.

In sunnier climes, solar power could complemint wind. More solar in summer and good weather, more wind in winter and bad weather. Oddly enough generated wind power too lessens at night !

spooiirt!!

I saw a graph on some damn website i cant find again, royal college of something, anyway it compared the costs of wind (with and without backup), to coal and gas. Even without backup, wind was more expensive than conventional energy. With backup, it was around twice as expensive. Im sorry that i cant give the name of the site ( i looked for quite some time, but to no stira). But on a kraut site it says wind power: 9cts/kwh, whereas coal is about 2cts/kwh. Same (approx )with solar.
If u dont believe me, email this lad:
Ludwig.Lindner@buerger-fuer-technik.de
Hes some prof or something ( im very tired), im sure he speaks english.


Ive noticed its very difficult to find the complete cost of wind energy ( cost of materials, assembly, maintenance + cost of backup) on the net. Like ive said, that german site showed wind as more expensive. As for predicting wind, that link you gave said wind can be predicted up to 36 hours ahead ( im too tired to read all of it now). But if we are able to accurately predict wind, why would we have 6 plants running continuously in germany for backup? 36 hours warning should be enough to start powering up the plants. So we clearly arent able to accurately predict the changes in wind, otherwise why would the plants here be running constantly?
Furthermore, sometimes wind blows stronger, and sometimes weaker, but at different times of the day we use different amounts of energy. So what if theres a serious drop in wind at a peak time? That means we need more backups then dont it?

Keeks

This is taken from the british sustanible development commisons november report "Wind Power in The UK". See here for the full report.

Intermittency
Wind blows at variable speed, variable intensity
and sometimes not at all. But this variability is
not a problem for the electricity grid. Wind is
accurately forecast over the timeframes relevant
to network operators and other market
participants. Increasing the proportion of wind
power in the electricity system does not require
greater “back up” capacity, as is often believed,
but it does slightly increase the cost. The greater
the proportion of wind on the grid the lower its
“capacity value”, and the lower the quantities of
conventional technology it displaces.
Nevertheless it continues to reduce carbon
emissions.
Costs
The generation costs of onshore wind power are
around 3.2p/kWh (+/-0.3p/kWh), with offshore
at around 5.5p/kWh, compared to a wholesale
price for electricity of around 3.0p/kWh. The
additional system cost is estimated to be around
0.17p/kWh, when there is 20% wind power on
the system. Generation costs are likely to
decrease over time as the technology improves,
but this will be balanced against increased costs
for integrating higher levels of wind generation
into the system.

You have to remember too that this data is based on older technologies. If you look at the windfarms mention above, such as Llandinam which has 113 turbines with a capacity of 30MW, this could be replaced with a 10-12 turbine site producing the same amount of enegy with lower costs.

Also to answer the question about a serious drop of wind at peak time. Actually I dont think it is the right question to ask. All power generation methods have similar problems. What if the gas pipe line bursts going into the power station? The water drys up at a hydro station? How is the national grid operators supposed to predict this.

Studies show that wind power follows human power consumption. (i'll try to dig some out later.) This measn that wind is strongest during peak times during the day a less during the night, more in the winter, less in the summer etc. These studies have been conducted in Denmark for over 25 years, and in a country that produces about 20% of its enegy from wind and trying to increase it to about 25%. I'll try to find some data on this

constitutionus

you know in terms of alternative energy resources can someone please tell me why we cant slave a small wind farm to a pump sucking sea water out of the irish sea / atlantic, use the wind generated electricity to electorlise it into its constituants of hydrogen and oxygen , preasurise it and pum it down to a modified natural gas electricity generating station and burn it

maybe im execptionally thick but if we had fuel generating stations like this all around the coast we could not only generate all our own electrical needs but we could become a net producer of electricity for the rest of europe. hell if we hooked up a coolant plant to it we could liquidise it and flog it to the european space agency, i mean it IS rocket fuel:) .

i realise its not much help to the rest of europe but we're an island nation and i think it could work out fine for us.
even if there was no wind blowing theres nothing to stop us having a storage plant for such an eventuality. and best of all the pollution of burning hydrogen and oxygen is water:D

again, feel free to pick this apart but i think it could really work and i dont know why something like this HASNT been tried

Capt'n Midnight

constitutionus wrote:

you know in terms of alternative energy resources can someone please tell me why we cant slave a small wind farm to a pump sucking sea water out of the irish sea / atlantic, use the wind generated electricity to electorlise it into its constituants of hydrogen and oxygen , preasurise it and pum it down to a modified natural gas electricity generating station and burn it

Electricity into H2 and then burn it to produce electricity, maybe 40% tops efficiency. Pumped storage is much more efficient. Unless you use the H2 in cars or portable Fuel cells. At present a fuel cell power station would be more efficient but more expensive too.

hell if we hooked up a coolant plant to it we could liquidise it and flog it to the european space agency, i mean it IS rocket fuel:) .

Saturn V used paraffin for most of it's fuel. the problem with Hydrogen is storage. It's 1/10 the density of water, so for example the biggest road legal artic tanker might only hold 3 tonnes, and that would have to be vented all the time to keep the pressure down. The shuttle uses aluminium powder, possibly using some produced from the bauxite refined by Aughinish Alumina. Actually aluminium is electricity since it's the only way to make it economically and it uses a lot more per Kg than say copper.

The main problem is that fossil fuel is the second cheapest way of making electricity after hydro. And most of the large scale hydro schemes that are going to be build have been build or would not get planning permission - at present we get 5% of electricity that way.

constitutionus

thanks man. i just thought it was a good idea. essentially using a small wind farm to act as a battery to get the real fuel your after, the hydrogen and oxygen.
the effeciancy may not be the best but the fact the planets effectively COVERED in your main fuel source seems to be an attractive idea. once you get the infrastructure in hopefully economies of scale should kick in

incidently i think its a disgrace what you said about hydro. i mean ALL the major cities in this country have at least 3 rivers going into em yet no one thinks daming one of these could help aleviate the electrical needs of the city.
why do we have to have one or two HUGE stations when we could have dozens of small scale ones contributing to the grid

i should point out (as if its needed:D ) im not hugely au fait on these issues, just an interested guy who is a little confused at the LACK of interest on a political level in the development of new energy sources and the future energy needs of the country as a whole:rolleyes:

air

Hyrdro creates it's own problems, not least of all the amount of land it consumes. With the current price of land in Ireland I can't see any new hydro stations in the near future.
Micro hydro is another issue and is something which can be extremely economically viable for those near a suitable site.