Wind farm capacity factors

truerenew

Hi there,

Anyone got any idea if there is any studies into Irish wind farm capacity factors? Just after reading the BERR study and the UK average was 0.29 from 1998-2004.

It was commented in another study that some policymakers used an unrealistic value of 0.35 for the UK.

Any comments?

ConsiderThis

truerenew wrote: »

Hi there,

Anyone got any idea if there is any studies into Irish wind farm capacity factors? Just after reading the BERR study and the UK average was 0.29 from 1998-2004.

It was commented in another study that some policymakers used an unrealistic value of 0.35 for the UK.

Any comments?

I'm sure I read that the very best performance recorded for Ireland was about 35%.

Nukem

ConsiderThis wrote: »

I'm sure I read that the very best performance recorded for Ireland was about 35%.

Thats 35% of Max demand I take it? The policy target is 40% by 2020 for renewables and majority to be made up from wind, as far as I have read. Limiting factors are the grid and load balancing as far as I know.

maniac101

truerenew wrote: »

Hi there,

Anyone got any idea if there is any studies into Irish wind farm capacity factors? Just after reading the BERR study and the UK average was 0.29 from 1998-2004.

It was commented in another study that some policymakers used an unrealistic value of 0.35 for the UK.

Any comments?

The figure for 2009 was around 31% for the whole island according to the IWEA. I'd expect that figure will come down a little in the coming years when the best onshore sites are all occupied and the installed onshore capacity continues to increase.

The current* grid connected and operational installed wind capacity on the island of Ireland is 1457.35 Megawatts (MW) which will on average generate 3,957,580 Megawatt hours (MWh) in a year given a 31% load**or capacity factor.

Macha

maniac101 wrote: »

The figure for 2009 was around 31% for the whole island according to the IWEA. I'd expect that figure will come down a little in the coming years when the best onshore sites are all occupied and the installed onshore capacity continues to increase.

I'd actually expect it to go up with increased installation of offshore wind.

ConsiderThis

taconnol wrote: »

I'd actually expect it to go up with increased installation of offshore wind.

You'd expect the average to increase with more wind farms? Surely the ones we have now were placed where they are in the windiest positions, so any new wind farms are less likely to be in such windy spots, which suggests that the average is more likely to decrease.

Macha

ConsiderThis wrote: »

You'd expect the average to increase with more wind farms? Surely the ones we have now were placed where they are in the windiest positions, so any new wind farms are less likely to be in such windy spots, which suggests that the average is more likely to decrease.

You would think so but actually the best wind resources and highest capacity factors are in offshore wind, not onshore.

But the technology to fully exploit offshore wind, including turbine design, construction vessel design & availability and dedicated ports have all been missing. Why do you think the Arklow wind farm is on the Arklow Bank? Because it's shallower than anywhere else offshore in the Irish Sea. As these technology gaps are filled, we should be in a better position to take full advantage of our offshore wind resources and see higher capacity factors.

ConsiderThis

taconnol wrote: »

You would think so but actually the best wind resources and highest capacity factors are in offshore wind, not onshore.

But the technology to fully exploit offshore wind, including turbine design, construction vessel design & availability and dedicated ports have all been missing. Why do you think the Arklow wind farm is on the Arklow Bank? Because it's shallower than anywhere else offshore in the Irish Sea. As these technology gaps are filled, we should be in a better position to take full advantage of our offshore wind resources and see higher capacity factors.

Of course, this being the green forum, we have to consider the extra cost of installation, of maintenance and of connecting the turbines in the sea to the grid. i wonder if we put all that in the cake mixer, what the result might be?

Heroditas

ConsiderThis wrote: »

Of course, this being the green forum, we have to consider the extra cost of installation, of maintenance and of connecting the turbines in the sea to the grid. i wonder if we put all that in the cake mixer, what the result might be?

Ease (or lack thereof) of access to turbines in the middle of the sea is also a massive issue.

Macha

ConsiderThis wrote: »

Of course, this being the green forum, we have to consider the extra cost of installation, of maintenance and of connecting the turbines in the sea to the grid. i wonder if we put all that in the cake mixer, what the result might be?

Yes there is additional cost but the question was about capacity factors. The area has attracted huge investment from the private sector across Europe and we are lagging behind. Just look up Bremerhaven in Germany.

Heroditas wrote: »

Ease (or lack thereof) of access to turbines in the middle of the sea is also a massive issue.

The access to turbines depends on onshore O&M facilities and service transport, including vessels and helicopters. A number of suitable vessels are under development, including a catamaran by Windcat Workboats and the Ampelmann system by TU Delft.

ConsiderThis

taconnol wrote: »

Yes there is additional cost but the question was about capacity factors. The area has attracted huge investment from the private sector across Europe and we are lagging behind. Just look up Bremerhaven in Germany.


The access to turbines depends on onshore O&M facilities and service transport, including vessels and helicopters. A number of suitable vessels are under development, including a catamaran by Windcat Workboats and the Ampelmann system by TU Delft.

Capacity isn't the only question, and it would be interesting to know what the additional cost is when it comes to maintenance, both regular and emergency, and how this affects the extra revenue expected by increasing the percentage efficiency gained by siting the turbines in the sea, or even if this might be attained. It certainly sounds considerably more expensive to send a maintenance crew to a site surrounded by sea water rather than surrounded by grass in a field.

Heroditas

taconnol wrote: »

The access to turbines depends on onshore O&M facilities and service transport, including vessels and helicopters. A number of suitable vessels are under development, including a catamaran by Windcat Workboats and the Ampelmann system by TU Delft.

Accessing turbines in the middle of winter in remote areas on land is an issue at the moment.
Accessing a battery of turbines out in the Atlantic in the middle of a winter storm will still be an issue, suitable vessels or not.

And yes, I've read this:

http://www.wind-energy-the-facts.org/en/part-i-technology/chapter-5-offshore/wind-turbine-technology-for-offshore-locations/

Changing a gearbox in a storm in the Atlantic will be a massive challenge.
Overcoming this challenge will introduce a large cost.

McSandwich

Heroditas wrote: »

Accessing turbines in the middle of winter in remote areas on land is an issue at the moment.
Accessing a battery of turbines out in the Atlantic in the middle of a winter storm will still be an issue, suitable vessels or not.

And yes, I've read this:

http://www.wind-energy-the-facts.org/en/part-i-technology/chapter-5-offshore/wind-turbine-technology-for-offshore-locations/

Changing a gearbox in a storm in the Atlantic will be a massive challenge.
Overcoming this challenge will introduce a large cost.

Gearless wind turbines have the potential to overcome these problems

For example:
http://w1.siemens.com/press/en/presspicture/?press=/en/presspicture/pictures-photonews/2008/pn200818.php

http://www.technologyreview.com/energy/23517/page1/

Heroditas

McSandwich wrote: »

Gearless wind turbines have the potential to overcome these problems

For example:
http://w1.siemens.com/press/en/presspicture/?press=/en/presspicture/pictures-photonews/2008/pn200818.php

http://www.technologyreview.com/energy/23517/page1/

Changing a gearbox is just one example of possible necessary maintenance.
Replacing a broken blade is another.

McSandwich

Heroditas wrote: »

Changing a gearbox is just one example of possible necessary maintenance.
Replacing a broken blade is another.

Come on, nothing is maintenance free or 100% reliable! However, a single turbine failure is unlikely to bring down an entire wind farm (aside from a domino effect if one fell over )...

What are your solutions/ alternatives?

ConsiderThis

McSandwich wrote: »

Come on, nothing is maintenance free or 100% reliable! However, a single turbine failure is unlikely to bring down an entire wind farm (aside from a domino effect if one fell over )...

What are your solutions/ alternatives?

But it is likely to bring down the percentage efficiency, which is why taconnol tells us the turbines are being placed at sea in the first place.

It would be interesting to see if the any marginal benefit from being placed at sea was greater than the marginal extra cost of (i) siting them three (ii) connecting to the national grid and (iii) the increased maintenance.

Macha

ConsiderThis wrote: »

But it is likely to bring down the percentage efficiency, which is why taconnol tells us the turbines are being placed at sea in the first place.

All wind turbines suffer from failures, including onshore. The capacity factor incorporates down time due to lack of wind and other factors.

ConsiderThis wrote: »

It would be interesting to see if the any marginal benefit from being placed at sea was greater than the marginal extra cost of (i) siting them three (ii) connecting to the national grid and (iii) the increased maintenance.

There is another significant issue and that is community opposition to wind farms. Offshore wind benefits from minimal opposition, resulting in significantly reduced planning costs. The other issue with wind turbines is that for onshore, at least, O&M makes up approximately 3% of total costs over the lifetime of the turbine. This % will obviously increase with offshore but the main costs to consider are that of construction and installation, not O&M.

Reducing costs is a priority and the main ways to do so are to invest in technology advances through R&D and also help make sure that the most suitable sites are open for installation (ie make sure the regulation is in place). This last action is estimated to have the potential to limit costs by up to 40%.

And remember a lot of this CBA is dependent on the price of oil & gas, both of which have been forecast to increase dramatically by the IEA.

ConsiderThis

taconnol wrote: »

All wind turbines suffer from failures, including onshore. The capacity factor incorporates down time due to lack of wind and other factors.


There is another significant issue and that is community opposition to wind farms. Offshore wind benefits from minimal opposition, resulting in significantly reduced planning costs. The other issue with wind turbines is that for onshore, at least, O&M makes up approximately 3% of total costs over the lifetime of the turbine. This % will obviously increase with offshore but the main costs to consider are that of construction and installation, not O&M.

Reducing costs is a priority and the main ways to do so are to invest in technology advances through R&D and also help make sure that the most suitable sites are open for installation (ie make sure the regulation is in place). This last action is estimated to have the potential to limit costs by up to 40%.

And remember a lot of this CBA is dependent on the price of oil & gas, both of which have been forecast to increase dramatically by the IEA.

It's the marginal extra costs involved with siting the turbines in the sea, compared with the marginal extra revenue generated ( if any) of siting them in the sea that would be interesting to see.

Macha

ConsiderThis wrote: »

It's the marginal extra costs involved with siting the turbines in the sea, compared with the marginal extra revenue generated ( if any) of siting them in the sea that would be interesting to see.

That is a difficult question to answer because you see a proper map of the exact potential sites in Ireland hasn't been done yet. AFAIK, SEI are working on it at the moment.

Costs can vary depending on site access, port facilities, waiting times for installation vessels and teams, delays in planning, specific turbine design, delays in turbine manufacture, distance of turbine components manufacture location from turbine assembly location etc etc etc.

And then of course the revenue generated depends on feed-in tariffs and of course the cost of electricity.

The UK, Denmark & Germany probably have some past examples - they're probably your best bet.

McSandwich

ConsiderThis wrote: »

It's the marginal extra costs involved with siting the turbines in the sea, compared with the marginal extra revenue generated ( if any) of siting them in the sea that would be interesting to see.

I suppose margins need to be compared with alternatives, i.e. with electricity from cheap oil and gas, but the price of wind as a fuel is constant (and free). If if suitable onshore sites were not available, then offshore would become more attractive.

ConsiderThis

McSandwich wrote: »

I suppose margins need to be compared with alternatives, i.e. with electricity from cheap oil and gas, but the price of wind as a fuel is constant (and free). If if suitable onshore sites were not available, then offshore would become more attractive.

Wind power is neither constant or free. The very best wind turbines in ireland are only producing elctricity 33% of the time, ( ie they are not producing any electricity 66% of the time), and there are costs associated with the production, both upfront costs and ongoing costs, which mean its not free!

McSandwich

ConsiderThis wrote: »

Wind power is neither constant or free. The very best wind turbines in ireland are only producing elctricity 33% of the time, ( ie they are not producing any electricity 66% of the time), and there are costs associated with the production, both upfront costs and ongoing costs, which mean its not free!

The same costs apply to any electricity generation. Downtime is inevitable for whatever reason and backup capacity must be available.

As an energy source wind is free and will always be free until someone finds a way to control it. Wind may not be constant (at least at one location) but it predictable in terms of when and how strong it blows and also how much it blows over a given time period. Look at the met.ie wind data for proof of this.

ConsiderThis

McSandwich wrote: »

The same costs apply to any electricity generation. Downtime is inevitable for whatever reason and backup capacity must be available.

As an energy source wind is free and will always be free until someone finds a way to control it. Wind may not be constant (at least at one location) but it predictable in terms of when and how strong it blows and also how much it blows over a given time period. Look at the met.ie wind data for proof of this.

Sure, the wind is free. The costs involved are incurred in trying to harness it.

I'm surprised that you claim its predictable as to when it will blow and predictable as to how strongly it will blow. In any case, its still the case that the best recorded in Ireland, from memory, is +-35%, whihc of course means that the best turbines in ireland are not producing electricity for 65 hours out of every 100 hours.

McSandwich

ConsiderThis wrote: »

Sure, the wind is free. The costs involved are incurred in trying to harness it.

I'm surprised that you claim its predictable as to when it will blow and predictable as to how strongly it will blow. In any case, its still the case that the best recorded in Ireland, from memory, is +-35%, whihc of course means that the best turbines in ireland are not producing electricity for 65 hours out of every 100 hours.

While wind power cannot be guaranteed for a particular day, it can be predicted with a high degree of certainty in a short time frame. For example, 45kph SE wind is forecasted for in Galway tomorrow and 23kph SW on Friday. This is enough for grid balancing purposes so that for example gas and goal fired generation can be reduced for those times.

As you said the annual capacity value for wind in Ireland is about 35%. However, it is higher during winter, when energy demands are also higher. To put it into perspective, the capacity values of Nuclear and Gas/Coal are 75% and 90% respectively - not exactly guaranteed.

I'm not saying that over reliance on wind (or any other single renewable source) is a good idea. It should be balanced by other sources (renewable or otherwise) as part of a 'smart grid'.

The costs will become more acceptable as the costs of other fuels increase (or just fluctuate with the markets). High energy users (such as data centres) require guaranteed supply and pricing above all else.

Heroditas

McSandwich wrote: »

As you said the annual capacity value for wind in Ireland is about 35%. However, it is higher during winter, when energy demands are also higher.

Not strictly true.
Winter days - frosty weather .... periods of high pressure, i.e. no wind

Macha

Heroditas wrote: »

Not strictly true.
Winter days - frosty weather .... periods of high pressure, i.e. no wind

S/he is talking averages.

Heroditas

taconnol wrote: »

S/he is talking averages.

Average availability isn't much use when energy demands are at their highest though.

Macha

Heroditas wrote: »

Average availability isn't much use when energy demands are at their highest though.

I refer you to McSandwich's above post:

McSandwich wrote: »

While wind power cannot be guaranteed for a particular day, it can be predicted with a high degree of certainty in a short time frame. For example, 45kph SE wind is forecasted for in Galway tomorrow and 23kph SW on Friday. This is enough for grid balancing purposes so that for example gas and goal fired generation can be reduced for those times.

As you said the annual capacity value for wind in Ireland is about 35%. However, it is higher during winter, when energy demands are also higher. To put it into perspective, the capacity values of Nuclear and Gas/Coal are 75% and 90% respectively - not exactly guaranteed.

I'm not saying that over reliance on wind (or any other single renewable source) is a good idea. It should be balanced by other sources (renewable or otherwise) as part of a 'smart grid'.

The costs will become more acceptable as the costs of other fuels increase (or just fluctuate with the markets). High energy users (such as data centres) require guaranteed supply and pricing above all else.

Heroditas

taconnol wrote: »

I refer you to McSandwich's above post:

McSandwich's post, while valid, can't be completely taken at face value due to the fact that there have been numerous occasions when the wind has dropped completely unexpectedly and the fossil fuel plants are fired up at short notice.
This has resulted in horrendous costs incurred to the SEM pool price - in some cases rising to over €1000 per MWh

This does not happen with the conventional power plants because it is akin to two or three of them catastrophically losing all generating capability at the same time.

McSandwich

Heroditas wrote: »

McSandwich's post, while valid, can't be completely taken at face value due to the fact that there have been numerous occasions when the wind has dropped completely unexpectedly and the fossil fuel plants are fired up at short notice.
This has resulted in horrendous costs incurred to the SEM pool price - in some cases rising to over €1000 per MWh

This does not happen with the conventional power plants because it is akin to two or three of them catastrophically losing all generating capability at the same time.

Do you have any links for this? I'd be interested. There should be enough spare grid capacity to avoid this. There was a moratorium on new wind energy grid connections during upgrades etc. As far as I remember the Irish grid can work with up to 20% wind generation.

What if Moneypoint (1.7GW) failed? I don't think there would be enough extra capacity to cover that during peak usage. Over reliance on one source, no matter what the fuel, is risky.

The effects of wind power variability are also reduced by locating wind farms in different geographical regions and offshore.

Other methods could be employed to support higher levels of variable sources, including:

1. Import via the grid inter-connector.

2. Grid storage where surplus energy is stored when supply exceeds demand.

3. Special supply contracts for high usage commercial customers who agree to payment for reducing their electricity usage at short notice.

4. "Small", quickly available backup generators (usually gas fueled).

BTW, how would you secure our future electricity supply?

johnathan woss

Heroditas wrote: »

McSandwich's post, while valid, can't be completely taken at face value due to the fact that there have been numerous occasions when the wind has dropped completely unexpectedly and the fossil fuel plants are fired up at short notice.
This has resulted in horrendous costs incurred to the SEM pool price - in some cases rising to over €1000 per MWh

This does not happen with the conventional power plants because it is akin to two or three of them catastrophically losing all generating capability at the same time.

You make a good point but the pool price has never been over €1000/MWh.

Heroditas

McSandwich wrote: »

Do you have any links for this? I'd be interested. There should be enough spare grid capacity to avoid this. There was a moratorium on new wind energy grid connections during upgrades etc. As far as I remember the Irish grid can work with up to 20% wind generation.

There is a large excess of capacity at the moment. This will be exacerbated even more with all the new gas powered generators coming on board, i.e. Whitegate, Aghada, Edenderry etc.
The current grid can indeed work with up to 20% wind generation but improvements are needed.

McSandwich wrote: »

What if Moneypoint (1.7GW) failed? I don't think there would be enough extra capacity to cover that during peak usage. Over reliance on one source, no matter what the fuel, is risky.

Moneypoint hasn't been generating for a number of months now. It's inefficient and isn't called on during the bidding process due to the inefficiencies and higher costs associated with it.

McSandwich wrote: »

The effects of wind power variability are also reduced by locating wind farms in different geographical regions and offshore.

Of course. However, an optimal figure of 40% is very good for wind.
So to obtain a constant 10MW of wind power, you need 25MW of turbines dotted around the place.

McSandwich wrote: »

Other methods could be employed to support higher levels of variable sources, including:

1. Import via the grid inter-connector.

2. Grid storage where surplus energy is stored when supply exceeds demand.

3. Special supply contracts for high usage commercial customers who agree to payment for reducing their electricity usage at short notice.

4. "Small", quickly available backup generators (usually gas fueled).

BTW, how would you secure our future electricity supply?

We already have those 4 mechanisms in place:
1. The interconnector between North and south and will be joined by the interconnector to Wales

2. Grid storage - Turlough Hill is a prime example

3. High usage customers already sign up for the WPDRS and they use point 4 to help them in those timeframes, i.e. they generate their own electricity using on-site generation.

There's no easy answer to the supply.
The immediate future is not as bad as the doom merchants are claiming. There are ample supplies of gas and LNG supplies are growing. These will help alleviate the issues we see when Russia flexes her muscles with her neighbours.
Gas prices are falling a lot anyway, particularly due to the glut of LNG arriving on the market.

It's vital that we investigate alternative sources of energy generation such as solving any problems with wind power and ensuring there are systems to back up this source of power.
In the meantime, we can continue to use gas until these alternatives are cost effective and fully dependable.

Heroditas

johnathan woss wrote: »

You make a good point but the pool price has never been over €1000/MWh.

While it's capped at €500, the "real" price was over a grand for a short period back in 2008 one day.
The pool absorbed the hit that time.

McSandwich

Heroditas wrote: »

There is a large excess of capacity at the moment. This will be exacerbated even more with all the new gas powered generators coming on board, i.e. Whitegate, Aghada, Edenderry etc.
The current grid can indeed work with up to 20% wind generation but improvements are needed.

Moneypoint hasn't been generating for a number of months now. It's inefficient and isn't called on during the bidding process due to the inefficiencies and higher costs associated with it.

I was misinformed about this - the last I read the decision to close was reversed in favour of an upgrade and continued generation until 2030.

Of course. However, an optimal figure of 40% is very good for wind.
So to obtain a constant 10MW of wind power, you need 25MW of turbines dotted around the place.

As costs come down, and the technology improves, this will become a viable option. Of course this would have to be balanced appropriately with other renewable and conventional generation.

We already have those 4 mechanisms in place:

But they need much more development if they are to support renewable electricity - especially grid storage, though trade via the new interconnector may be sufficient.

Currently a Donegal wind farm uses a 39MW flow battery to store surplus energy and the ESBs electric vehicle plans should be interesting for grid storage/ making use of off peak wind.

There's no easy answer to the supply.
The immediate future is not as bad as the doom merchants are claiming. There are ample supplies of gas and LNG supplies are growing. These will help alleviate the issues we see when Russia flexes her muscles with her neighbours.
Gas prices are falling a lot anyway, particularly due to the glut of LNG arriving on the market.

I wonder how much of this is due to recession and what will happen when the world economies start growing gain - especially China and India.

It was worrying that gas supplies to industrial users was restricted in Britain during the cold weather - especially as most of our supply is via the UK. There was talk of price increases over there on the same day that price reductions were announced here!

It's vital that we investigate alternative sources of energy generation such as solving any problems with wind power and ensuring there are systems to back up this source of power.
In the meantime, we can continue to use gas until these alternatives are cost effective and fully dependable.

I agree completely. We need to research and develop viable alternatives and improve grid infrastructure to ensure that, as a nation, we don't wake up some morning to find our kettles won't boil!

Cunsiderthis

McSandwich wrote: »

...Currently a Donegal wind farm uses a 39MW flow battery to store surplus energy and the ESBs electric vehicle plans should be interesting for grid storage/ making use of off peak wind...

I'm really interested in this, as I didn't know the batters existed that could store enough electricity to, say, power a small housing eatste who heated theire water in immersion heaters via electricity.

Have you details somewhere where I can find out more about the technical specification of the batteries used by this wind farm and what capacity they have?

McSandwich

Cunsiderthis wrote: »

I'm really interested in this, as I didn't know the batters existed that could store enough electricity to, say, power a small housing eatste who heated theire water in immersion heaters via electricity.

Have you details somewhere where I can find out more about the technical specification of the batteries used by this wind farm and what capacity they have?

Sorry, I got that mixed up, should be 39MW generating capacity with 12MW flow battery storage.

Details here:

http://www.sei.ie/Publications/Renewables_Publications/VRB-ESS-Energy-Storage-Rpt-Final.pdf

http://ehp.niehs.nih.gov/members/2007/115-7/innovations.html

Based on this technology:

http://www.pdenergy.com/en/technology/energy_storage_systems/how_it_works/how_it_works.html

More on storage technologies here:

http://www.iwea.com/index.cfm/page/technologicaldevelopments?twfId=43&download=true

Cunsiderthis

McSandwich wrote: »

Sorry, I got that mixed up, should be 39MW generating capacity with 12MW flow battery storage.

Details here:

http://www.sei.ie/Publications/Renewables_Publications/VRB-ESS-Energy-Storage-Rpt-Final.pdf

http://ehp.niehs.nih.gov/members/2007/115-7/innovations.html

Based on this technology:

http://www.pdenergy.com/en/technology/energy_storage_systems/how_it_works/how_it_works.html

More on storage technologies here:

http://www.iwea.com/index.cfm/page/technologicaldevelopments?twfId=43&download=true

Wow, they certainly make interesting claims for the technology and it wil be great to see the results of tests, and to see if its economically & practically feasible.