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« Material World on gas and climate models | Main | Wood insanity be the reason? »

Missing the point?

There is lots of excitement among greens this morning over an article by Mark Lynas, which purports to show that wind farms do not increase carbon emissions.

From analysing National Grid data of more than 4,000 half-hour periods over the last three months, a strong correlation between windiness and a reduction in gas-fired generation becomes clear. The exchange rate is about one for one: a megawatt hour of wind typically meant the UK grid used one less megawatt hour of gas-derived electricity. This means that actual CO2 savings can be calculated from the data with a high degree of accuracy – these are not guesstimates from models, but observations of real-world data.

Over a year, based on the amount of electricity wind is currently generating each day, wind turbines save around 6.1m tonnes of carbon dioxide, or about 4% of the UK's emissions from electricity (based on CCGT plants emitting around 350 kg CO2 per mWh). This figure provides independent confirmation for the trade body RenewableUK's estimate of a current reduction in annual emissions from the entire UK wind fleet of about 6m tonnes.

I haven't had a chance to go through this thoroughly, but at first glance the article appears to be entirely risible. The wind-sceptic argument is that efficiency losses in gas-fired generators offset (perhaps more than offset) any emissions savings from wind. So to show that wind power replaces gas-fired generation on a one-to-one basis is completely irrelevant seems to miss the point - it is a statement of the patently obvious, since supply (we hope) has to meet demand.

The question that needs to be addressed is that of the efficiency of the gas-fired generation that is still operating.

Or am I missing something in Lynas's argument?

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Reader Comments (127)

Surely there is little to no reductions simply because the gas fired power stations are running regardless of whether the windmills are turning or not?


Sep 26, 2012 at 10:43 AM | Unregistered CommenterMailman

".....wind turbines save around 6.1m tonnes of carbon dioxide, or about 4% of the UK's emissions from electricity (based on CCGT plants emitting around 350 kg CO2 per mWh)."

Err no.

DEFRA insist BRE use a figure of 198 kgCO2/mWh for Natural Gas when assessing the Carbon Footprint of prospective new-build properties.

So wind turbines save (vs Nat Gas) only around 3.45m tonnes of carbon dioxide, or about 2.26% of the UK's emissions.

Sep 26, 2012 at 10:52 AM | Unregistered CommenterJoe Public

No you're not missing anything. This is the same old tired argument about displacing generation, MW for MW without accounting for the change in efficiency or whether the same amount of fuel continues to be burnt and the excess energy is dumped.

Sep 26, 2012 at 11:02 AM | Unregistered CommenterPhillip Bratby

I think they just assume that when the wind blowes a magic fairy can instantly turn off a gas turbine, then it's stops blowing the fairy puts her paper down waves her magic wand it comes on again.

This doen't even take into account the constant change in supply from the gas turine due to the complete rtandomness of the wind the poor fairy died of a heart attack trying to keep up.

Sep 26, 2012 at 11:12 AM | Unregistered CommenterShevva

I think you are missing something - have a look at the stats first. The efficiency-loss argument depends on the assumption that inefficient open-cycle gas is used to back up intermittent wind. As we say in the piece, actually OCGT is almost never used (except in emergencies), and does not correlate at all with wind ups and downs. See for a graph of the relationship (I've taken out other generators so you can see just wind and OCGT) back to 2009.

Matt Ridley suggested that there might be CCGT in spinning reserve or something. I was at National Grid on Monday and talked to grid operators (in particular the wind people) about how it works. They have not so far had to upgrade the reserve capacity to cope with wind - 1GW is basically warm and ready to go all the time. As we say in the piece, a bigger danger is that some really big piece of kit like Sizewell B goes down - then you have to fire up a lot of backup very quickly. Wind tends to fade rather more gently, and is *reasonably* forecastable (you can see how actual wind correlates with forecasts on the site - graph is called 'Peak Wind Generation Forecast'.

There is certainly a debate to be had about how much higher generating capacity of wind will be integrated onto the grid, and what upgrades will be needed regarding interconnectors, pumped storage, reserve capacity etc. National Grid have a longish PDF which discusses the issues out to 2020 - a 'must read' for anyone following this debate. See for the downloads.

Sep 26, 2012 at 11:17 AM | Unregistered CommenterMark Lynas

Their first graph in the article... Total demand actually falls off like that towards the end of the week. You can see it as a regular thing on

I suppose they could have shown Friday, Saturday and Sunday where demand really falls off for the weekend, but I guess their wind data didn't work out for them.

Some time ago I downloaded the data from the above site and made audio files out of the various bits of data. All the reliable generators sound like a recording of mains hum. Nuclear is boring. Wind sounds, unsurprisingly, like wind.

Sep 26, 2012 at 11:21 AM | Unregistered CommenterReg. Blank

The key assumption in the Lynas/Goodall piece is surely that back-up power shows up as electricity in the statistics: "a megawatt hour of wind typically meant the UK grid used one less megawatt hour of gas-derived electricity". But surely the back up power is dumped as hot air and CO2 into the atmosphere. It's possible that wind is still a small enough contributor that the grid has not yet got to the point where it needs to increase its spinning reserve, which it anyway uses to cope with volatility in demand, but as wind grows then the reserve must grow.

In an article claiming conclusively to prove that wind cuts emissions, you might expect to see some data on emissions! But there are none. As the article says:

"Data, not assertions, are what must win the argument over wind".

Sep 26, 2012 at 11:21 AM | Unregistered CommenterMatt Ridley

One of the problems not addressed in the article is that some major power stations need replacing very soon (Fawley is due to close next year) and the government is still sitting on its hands. The greens don't want new conventional stations built, but fail to see that however many wind turbines you build instead, there will be times when they cannot contribute anything, so up to 60GW will have to provided by other means. That is the baseline.

I've no objections to turbines being used in addition, if they work, don't annoy people and don't enrich a few landowners with unnecessary subsidies.

Sep 26, 2012 at 11:29 AM | Unregistered CommenterJames P

The Carbon Trust's website today states the conversion factor (for Nat Gas) is actually 183.6 kg CO2 per mWh, NOT 350 kg CO2 per mWh as used by Mark Lynas

So it's 47% less than the propaganda would imply.

Sep 26, 2012 at 11:37 AM | Unregistered CommenterJoe Public

And the point about reducing CO2 emissions is?

Sep 26, 2012 at 11:37 AM | Unregistered CommenterMartin Mason

Call in Mr McIntyre, he will be able to fisk it straight away.

Sep 26, 2012 at 11:43 AM | Unregistered CommenterMorph


The efficiency-loss argument depends on the assumption that inefficient open-cycle gas is used to back up intermittent wind.

That's one possibility. The other one is that CCGT is used inefficiently. Another is that we need extra reserve capacity. Your argument appears to be based on the premise that the rest of the grid can adapt to wind without loss of efficiency. This is, with all due respect, bonkers.

I've read some of the docs on the Nat Grid page you cite. They say they are going to need a lot of reserve capacity to cope with wind:

Our current view is that reserve requirements will rise over the next decade as more wind generation is installed and larger generating units connect.

Sep 26, 2012 at 11:48 AM | Registered CommenterBishop Hill

Mark Lynas claims the data shows a one for one exchange between wind and gas-fired generation.

I see no such exchange.

Looking at DUKES data since 1970 it is possible to see several exchanges of the type Mark Lynas claims for gas and wind:
(a) between 1970 and 1990 there is an exchange of market share between increasing nuclear generation and decreasing coal-fired generation
(b) between 1990 and 2000/1 there is a similar exchange between coal and gas.
(c) since 2000 there's a slow decline in nuclear generation, a matching, but shallower rise in gas generation against a background declining total demand.
(d) since 2007 there has been a steep rise in wind generation (but the percentage share of the market has yet to reach 5%) with no discernable effect on the gas and coal fired market shares.

In Denmark and the Netherlands where wind's market share is significant analysts have been able to assess fuel savings, fossil-fired efficiency impacts and CO2 savings. But I don't see how we can repeat their methods for the UK market with such a low penetration of wind generation.

Sep 26, 2012 at 11:58 AM | Unregistered CommenterCapell

Bishop Hill

Well, at least we can agree that OCGT is not used to back up wind. So the Global Warming Policy Foundation's argument falls.

As to a declining efficiency of CCGT, Chris and I spoke at length to the manager of one of the UK's largest gas-fired power stations. There is some efficiency loss from running below full power or load following, but not much. About 3% I think at the absolute max - and wind hasn't so far changed the picture for grid management.

Yes for the future things will be different - but as the National Grid spokesperson said in our piece, "reserve requirements" could be anything - they are officially technology neutral on this. So it could be interconnections, more pumped storage, or simply more CCGT (a new plant, 2GW I think, just opened over in Pembrokeshire, so more gas is coming on all the time).

I don't know how far wind can fit into a grid which is changing all the time. Smart meters are meant to be in by 2017. Coal is closing because of LCPD. So is nuclear (unfortunately). How would wind work at 20%? 50%? I don't know, and I don't think anyone else does either. It is a very dynamic and complex picture. Another 500MW interconnector just opened to Ireland last week.

But blocking additional wind capacity today on the basis of factually unsupportable CO2 arguments is not a defensible position anymore. I hope we can agree on this at least.

Sep 26, 2012 at 12:02 PM | Unregistered CommenterMark Lynas

Mark Lynas and I wrote the article to illustrate the simple point that when the wind blows, gas turbine plants are switched off. As we all know, electricity supply is adjusted on a second-by-second basis to match demand. The pervasive illusion that back-up power stations continue to work just in case the wind drops is utterly, completely and totally mistaken. If you doubt me, ring up National Grid to ask.

At all times, the Grid does have some electricity generating capacity ready in reserve, waiting to move to full power. This is principally because of the risk that one or two large (fossil fuelled or nuclear) power stations will suddenly fail or lose their connections to the network. The 'spinning reserve' is also there to meet unexpected demand surges, such as might occur as a result of an unpredicted break in a popular sports event. (The set breaks in Murray's victory at the US Open are a good example). At present, the Grid has no requirement to have additional spinning reserve to meet wind's variations, which are far slower and more predictable than, say, the loss of Sizewell B.

At some points as wind grows, the number of gas-fired stations having to be operating part-loaded will to rise. This means that they will become less efficient, But the difference between the conversion efficiency of a part-loaded CCGT plant and one operating at full capacity is small. The manager of a large CCGT plant said to us that it increased his use of gas by 5-6%. Even with much larger numbers of wind turbines in the future, the impact of having one or two more CCGT stations operating below capacity will be minimal, both on the cost of power and on carbon emissions.

There's a last point that needs to be addressed. Some commentators claim that Open Cycle Gas Turbine plants (which operate with a conversion efficiency of around 32% compared to about 59% at the new 2 GW CCGT plant in Pembroke) will need to be employed. OCGT plants are actually used incredibly rarely in the UK (because they use so much gas) and only to meet emergencies. We couldn't find a single incidence of OCGT plant being fired up because of wind's variability. In fact, the industry sources we talked to didn't think OCGT would ever have to be used as a backup to wind.

The use of increasing number of wind turbines reduces the UK's emissions and decreases the amount of gas the country imports.

Chris Goodall

Sep 26, 2012 at 12:08 PM | Unregistered CommenterChris Goodall


"factually unsupportable CO2 arguments"

I'd be interested to know what facts support the argument that CO2 is the problem. I'm not sure that 'the IPCC says so' cuts it any more.

Sep 26, 2012 at 12:10 PM | Registered Commenterjamesp

Mark and Chris

What's your reaction to this study, coming to a diametrically opposite conclusion:

"Using wind data from a normal windy day in the Netherlands it will be shown that wind developments of various sizes cause extra fuel consumption instead of fuel saving, when compared to electricity production with modern high-efficiency gas turbines only. We demonstrate that such losses occur. Factors taken into account are: low thermal efficiency at low power; cycling of back up generators; energy needed to build and to install wind turbines; energy needed for cabling and net adaptation; increase of fuel consumption through partial replacement of efficient generators by low-efficiency, fast reacting OCGTs."

and this one:

"There is an inescapable consequence to introducing wind’s production persistently erratic (over shorter periods) and unreliable (over longer periods) into electricity systems. Other generation plants must react to wind’s random minute-to-minute fluctuations as well as longer term absences and appearances. In effect, wind is another form of load on the electricity system that must be responded to in addition to the “normal” changes in demand. This forces other generation plants to operate less efficiently than they would in “normal” operations providing the steady, reliable electricity supply that modern societies require...Considering all this, my inescapable position is that wind plant presence in an electricity system does not contribute to fuel or emissions savings, and may actually increase these."

Sep 26, 2012 at 12:21 PM | Unregistered CommenterMatt Ridley

I don't think that Lynas' analysis shows what he claims it shows. That's not to say he's wrong or right in his argument - just that's it's a bit of a spurious analysis. When wind turbines are putting 1GW onto the grid - it is a requirement that the people running the grid turn off 1GW of whatever it is that is easiest to turn on and off. If this didn't happen the voltage on the grid would rise and all our domestic appliances would blow up.

So he's proven there is a 1:1 correlation between the amount of wind turbine power generated and the amount of gas powered generation not used. Which proves that the people running the grid know how to turn things on and off at the right time.

He then multiples this number by another number to turn it into supposed CO2. What would actually be needed is to have measurements of the amount of CO2 coming out of the gas power stations. Or the amount of gas being used. And be able to show how that goes up or down vs wind level. Which actually might be rather tricky.

The actual benefit of wind in reducing CO2 must be below Lynas' number but hopefully greater than 0.



Sep 26, 2012 at 12:22 PM | Unregistered CommenterNickM

Where will the money come from to pay for all these CCGT plants to be kept on standby?

Sep 26, 2012 at 12:24 PM | Unregistered CommenterRosebank

Chris Goodall again.

For clarity, Mark and I are referring to the same conversation with a CCGT plant manager. This person said their plant efficiency fell from about 56% to about 53% when in part-load mode. Mark calls this a 3% loss in efficiency. I referred to the same number as a 6% increase in gas use per kWh of generation. Same underlying numbers.

Sep 26, 2012 at 12:25 PM | Unregistered CommenterChris Goodall

I've just looked again at DUKES data and gas generation efficiency has increased markedly during the period of increasing wind supplies, from ~42 % (2006) to ~45% (2011). The reason for that is nothing to do with market share but the arrival of more modern, higher efficiency CCGTs whilst the earliest CCGTs are being retired. During the same period fossil-fired (coal) generation is ~39 +/- 1 %.

It wouldn't surprise me if the systems operators more or less ignored the present wind variability and simply let it waggle grid frequency.

There are factual arguments supporting the contention that wind generation emission cuts are reduced because of the required part-loading of fossil-fired plant; it's just that these cannot be replicated for the UK market where wind's market share is presently small. And in those markets where there's significant wind generation there is also direct evidence of the use of OCGTs for regulation.
"an [NGT] spokesperson can say "reserve requirements" could be anything - they are officially technology neutral on this" is ridiculous. How can we continue with an expensive and environmentally damaging programme of increasing wind generation with the aim of decreasing fuel imports and reducing CO2 emissions when we have little idea of the impact on grid operations in an island grid and the scale of the benefits?

Sep 26, 2012 at 12:31 PM | Unregistered CommenterCapell

"For clarity, Mark and I are referring to the same conversation with a CCGT plant manager. This person said their plant efficiency fell from about 56% to about 53% when in part-load mode. Mark calls this a 3% loss in efficiency. I referred to the same number as a 6% increase in gas use per kWh of generation. Same underlying numbers."
Yes, but you're not reporting (a) how much your plant manager was proposing to back-off from maximum generation to give head-room for response, and (b) given that operating point, how much primary and secondary response he could then provide and (c) what percentage that would represent of NGT's total response requirement to regulate wind generation. But you can't do that because NGT have said the haven't a clue!

Sep 26, 2012 at 12:40 PM | Unregistered CommenterCapell

This is off topic, but it relates to Chris Goodall's general accuracy as a journalist and explains why I take his latest conclusion with a pinch of salt even if there was not counter-evidence. Today I left the following comment on Mr Goodall's own Carbon Commentary site, where he had written a long piece critical of my Wired article "Apocalypse Not".

Mr Goodall’s piece has so many errors in it, it is embarrassing. Let’s start with the repeated misspelling of “Ehrlich”. Not that it matters much, but it is indicative of sloppiness with respect to facts.

Then notice Mr Goodall’s attempt to combat my assertion that melanoma is not increasing with the following “jaw-dropping” remark: “increasing skin cancer incidence has been linked to rising UV-B radiation for several decades.” He gives no source for this. (My article has over 75 source links at my website: Is Mr Goodall unaware that most skin cancer is not melanoma? That the increase in other skin cancers is caused, most medical scientists think, by an increase in holidays in low latitudes, not a reduction in ozone in high latitudes?

As for his assertion that my language was “deliberately unclear” but I “seemed to be saying” that that CFCs were not the main cause of ozone loss, no, my language could not have been clearer: “The ozone hole still grows every Antarctic spring, to roughly the same extent each year. Nobody quite knows why. Some scientists think it is simply taking longer than expected for the chemicals to disintegrate; a few believe that the cause of the hole was misdiagnosed in the first place.”

here’s a graph showing the persistence of the zone hole —

There’s plenty more in the way of egregious mistakes in the piece that would never have got past the fact-checkers at Wired. His price graphs take no account of inflation! Minerals and cancers are cherry picked. etc etc. For anybody who open-mindedly wants to check my sources, they are linked at my website here:

where I have also added in some more examples of failed apocalyptic predictions that were left on the cutting room floor by Wired.

And the similarity of some parts of the Wired article to some parts of the Economist article is because I wrote them both.

Sep 26, 2012 at 12:45 PM | Unregistered CommenterMatt Ridley

Matt Ridley mentions the Le Pair paper, which often gets raised during debates on this topic. (James Lovelock was the first person to mention it to me - he, too, cites it in supporting his anti-wind stance.)

Just as further reading, it got discussed when I ran an Eco Audit on this topic back in January...

Sep 26, 2012 at 12:48 PM | Unregistered CommenterLeo Hickman

Both Denmark and Germany have increased their CO2 footprint with increased wind turbine use. It happens here regardless of the report above which seems to be based on wishful thinking rather than true observation and data.
Mark Lynas probably has a model.

Sep 26, 2012 at 12:55 PM | Unregistered CommenterJohn Marshall

So, now that we have established that 1GWh = 1GWh, what I would like to know is:

How much does 1GWh of wind energy cost? This must include not only direct payments to the generating company, subsidies, and payments to turn off the generation when it is not needed, but also any cost associated with backup provision.

Sep 26, 2012 at 12:58 PM | Unregistered CommenterHeide De Klein

This argument, about how much, or even if, the deployment of wind turbines reduce CO2 emissions, should have been made 20+ years ago before vast quantities of consumer's money was spent, vast expanse of landscape was despoilt and many people's lives and health were ruined. But that's politicians and green NGOs for you.

Sep 26, 2012 at 1:04 PM | Unregistered CommenterPhillip Bratby

In reply to Matt Ridley, and further to Leo's response, the Dutch paper is talking about an idealised mini grid with only gas and wind working together (and a very high wind penetration). This is not how a real grid works, like in the UK, with a much larger combination of plant types operating together. If we were to turn off all other sources, including coal, nuclear, hydro (PS and non) and interconnectors, then the le Pair study might have more relevance, and only then if we had truly massive amounts of wind and a single large gas power station to run the entire country.

What no-one seems to understand is that the grid is balancing all the time (they are legally mandated to keep the frequency of AC power within 0.2Hz of 50Hz), and that doing so does not require *every* CCGT plant to be running in half-mode and load-following. Most run on full power when they're on - and small variations will be followed by Dinorwig or interconnectors more likely than large amounts of gas coming on and off. So the efficiency loss of CCGT to 'back up' wind is really a non-argument in the real world, particularly as wind is quite forecastable hours in advance. You can watch the wind numbers change in realtime over at bmreports - you get a few tens of MW every few minutes, but nothing extreme.

Remember - demand changes are much greater and more sudden than supply changes from the likes of wind wind. When I was recently at National Grid control centre, I spoke to the person who forecasts what they call "TV pickups" in demand at commercial breaks in shows like EastEnders and Coronation Street. They get schedules from ITV of the exact second a commercial break is scheduled in order to plan. But they don't know exactly how demand will respond. Eg. in a recent Downton Abbey episode, they got the expected TV pickup in demand at the 3rd commercial break wrong by 300MW - and that happened within 3 seconds. No-one's lights went out, and no extra gas stations had to sit there at half power just because Downton was on the telly. Otherwise Downton would be a very CO2-intensive show!

Sep 26, 2012 at 1:07 PM | Unregistered CommenterMark Lynas

Anyone who thinks wind power can solve the power needs of a modern civilised economy and is efficient certainly have no scientific background?

I know this as a bloke down the pub told me or was it a plant manager?

Sep 26, 2012 at 1:13 PM | Unregistered CommenterStacey

Do the authors of the article live under, near, or within sight of that which they seem to adore? If they don't, would they buy a house situated under, near, or within sight of that which they seem to adore? Just asking.

Sep 26, 2012 at 1:16 PM | Unregistered CommenterEl Sabio

Where can I find an estimate of the energy used in manufacturing and transporting the components for a wind turbine, installing it and eventually decommissioning it?

What is the weight of steel in a typical wind turbine?

Sep 26, 2012 at 1:26 PM | Registered CommenterMartin A

"Eric Posner, a professor at the University of Chicago Law School, is a co-author of The Executive Unbound: After the Madisonian Republic and Climate Change Justice."

No surprises here then! Openly Fascist.

Sep 26, 2012 at 1:30 PM | Unregistered CommenterAC1

It has been reported that "constraint payments" have been paid to Wind generation operators who have been requested to turn off capacity when the network is not capable of handling the excess power generated.

Does the same apply to the gas powered generators when they have to back off to make way for any increases wind generation? Can't see them just accepting a reduction in revenue?

If so is not the inherent variability of wind capable of causing "constraint payments" as well as receiving them? Not sure about reducing efficiency but could impact upon the cost of generation as a whole.

Sep 26, 2012 at 1:36 PM | Registered CommenterGreen Sand

Sorry, have I just gone back in time? Why are we again being urged to demonise a harmless trace gas? (Lest we forget: man-made 'emissions' equal a mere 3% of 0.038% CO2 in the atmosphere; no warming this century, and longer).

Sep 26, 2012 at 1:46 PM | Unregistered CommenterBarbara

Mark Lynas "What no-one seems to understand....". Oh dear, now Mark Lynas, who no doubt has a lifetime's experience working in the power industry, is trying to teach us to suck eggs. Such arrogance - no wonder he is a journalist. As Kevin McLeod said on Grand Designs "I'm not an expert in anything, that's why I'm a TV presenter".

Sep 26, 2012 at 1:47 PM | Unregistered CommenterPhillip Bratby

Today's Guardian comes with a free CD of Pinocchio. How appropriate.

The line "a megawatt hour of wind typically meant the UK grid used one less megawatt hour of gas-derived electricity" is completely ridiculous and has been dealt with by Nick and Matt above.

Directly quoting the sceptics and then immediately misrepresenting their arguments is a remarkable achievement.

On twitter, Josh asked if the carbon cost of building all the turbines was taken into account. The answer was no. What about the carbon cost of building new power lines across Scotland?

Sep 26, 2012 at 1:50 PM | Registered CommenterPaul Matthews

OK, so with the current penetration of wind (10% / 15% ?) there's sufficient auxiliary power available to take up the slack when the wind isn't blowing, and when it is then that's gas/ coal that's saved.

What happens when wind reaches 30% or 40% (or God help up 100% like Salmond wants here in Scotland)?

What's the level at which wind can contribute whithout having to build conventional power stations just to back it up?

Sep 26, 2012 at 1:52 PM | Unregistered CommenterNial

Mark Lynas

What no-one seems to understand is that the grid is balancing all the time (they are legally mandated to keep the frequency of AC power within 0.2Hz of 50Hz)

It may be news to you, but not to me nor, I expect, to most of the readers here.

If you want to persusuade me, please don't be condescending.

Sep 26, 2012 at 1:53 PM | Registered CommenterDreadnought

OCGT capacity in the UK is just over one GW. It is hardly ever used and has nothing to do with supporting the inadequacies of wind turbines. So mentioning that was a red herring.

The grid has spinning reserve of 10%, roughly 3GW, to cover for major plant breakdown and surges in demand. The 4GW (now 5GW) of wind will be accommodated within this reserve. The problem arises in the future when we have 30GW of wind. It is then that fast acting reserve, much much greater than the current 3GW, will be needed. Ideally this would be hydro, like Spain who have as much hydro as they have nameplate wind capacity, which can be activated within seconds. We can't enjoy that advantage so we will need to deal with it using gas and to cover for 30GW of wind is going to require somewhere between 15 to 20GW of reserve, spinning or otherwise. Whether this reserve is the slow acting CCGT or fast acting, inefficient, OCGT remains to be seen.

Incidentally, I am confused with regard to the so called reduction in efficiency. To my mind a CCGT plant running in spinning reserve, consuming power but not producing electricity, is operating at zero efficiency. Could it be that the plant manager was referring to an average?

Sep 26, 2012 at 1:58 PM | Unregistered CommenterDavid Porter

It appears that there are two non-overlapping arguments being presented here.

The anti-wind view seems to be that when the wind stops blowing, you need to ramp up gas output by starting up the OCGT stations, or increasing output from otherwise idle CCGT on hot-standby. If this were true then indeed wind would be a bad idea.

But Mark and Chris (and the folk at the national Grid) appear to be saying that while wind can vary between producing 0 and 25% of the power required, the balance can mean CCGT running at between 100% and 75% capacity, with no requirement to ever turn on OCGT, and that reducing from 100 to 75% load involved only a 3% reduction in efficiency, or 6% increase in fuel/MW.

And to me, this makes a lot more sense than the idea that entire power stations must be turned on or off dependant on the weather. As Chris says, demand fluctuates far more over a normal week than the wind supply, so we're already coping with the up-and-down demands on the gas stations.

Overall, as long as wind remains a minority contributor it is a win in CO2 terms. This says nothing about costs/subsidies/noise/nuisance and all other possible problems of wind power.

Sep 26, 2012 at 2:00 PM | Registered Commentersteve ta


My point too. With his infinite wisdom and experience (or is it just and hour with National Grid), perhaps Mark Lynas can come down off his high horse and tells us plebs (that's a good word for us) which function wind turbines perform. Is it baseload, load follow or peak load?

Sep 26, 2012 at 2:01 PM | Unregistered CommenterPhillip Bratby

The argument over how much conventional powered plant has to back up Wind is missing the point. The very fact that reliable technology has to back up wind means that wind is an additional expense that is not required. Reducing plant efficiency from 56% to 53% basically means that the entire cost of wind is an additional expense to the consumer and tax payer. Reducing carbon is an insignificant contribution and a complete strawman if indeed there is a need to reduce it with such haste, which is still being debated.
The only benefit to the consumer and tax payer of any new technology would be cheaper power and that's not going to happen from a supplier point of view.

Sep 26, 2012 at 2:07 PM | Registered CommenterLord Beaverbrook

The conjecture is moot.

Listen lads, Lynas and Goodall, get this straight - we don't need wind power - if we have gas fired electrical generators but what's even more efficient, is to pump the gas directly to domestic and industrial users - now that is efficiency.
In power generation the best fuel to use is: coal.

Wind power, as the German model is neatly demonstrating - some of the time produces large amounts of useless power, the grid cannot take the fluctuating surges and they can't even export it - no one wants it - so the Germans are building ..................guess what? Yep, new build coal fired power generating plant.

The more a country depends on such sources of energy, the more there will arise – as Germany is discovering – two massive technical problems. One is that it becomes incredibly difficult to maintain a consistent supply of power to the grid, when that wildly fluctuating renewable output has to be balanced by input from conventional power stations. The other is that, to keep that back-up constantly available can require fossil-fuel power plants to run much of the time very inefficiently and expensively (incidentally chucking out so much more “carbon” than normal that it negates any supposed CO2 savings from the wind).

It ain't rocket science lads - wind power = green boondoggles.

Sep 26, 2012 at 2:07 PM | Unregistered CommenterAthelstan.

Can you take me through this one slowly: if as you say there is no need to have back-up capacity for wind power because it is already there to cope with set changes at Wimbledon, down time for nuclear plants etc, then why, apart from CO2 emissions management, do we use wind power at all? Clearly on flat calm days wind contributes nothing at all to the grid, but the supply can be maintained, so wind power is redundant in its entirety. Obviously this will change if wind plays a greater part in our energy production, but then we will encounter the problems of firing gas power up and down. You can't have it both ways.

Sep 26, 2012 at 2:18 PM | Unregistered CommenterDavid S

Mark Lynas,
Difficult to know where to start on your comments, but treating all would take too long.
"Wind tends to fade rather more gently.." I doubt that is true when maximum wind speeds are exceeded. I don't need to look at videos of wind-turbines on fire to suspect this.

I hope the *reasonably* forecastable wind isn't being *reasonably* forecast by the same people who are forecasting catastrophic anthropogenic global warming.

How often does Sizewell B go down [excluding scheduled outages]?

Is wind power currently merely taking up all the reserve 'slack' in the system that was built around existing generation capacity? Congratulations, you come very close to acknowledging that potential problems for the grid would then mount very rapidly if wind becomes greater than merely a parasite on other generation methods.

Also, I'll listen to what grid engineers say [if/when they are allowed to openly do so in public], not what YOU report, or imply, they might have said.

Sep 26, 2012 at 2:20 PM | Unregistered Commentermichael hart

For me this is an irrelevant argument. Frankly, I don't care what the CO2 emission figures are.

I do care about the fact that the following power stations will be closed by March 2013 - six months from now:

Didcot A, Fawley, Kingsnorth, Isle of Grain, and Cockenzie. A total capacity of roughly 7500 MW.

Now that is alarming!

Sep 26, 2012 at 2:20 PM | Unregistered Commenterstanj

@Mark Lynas

Why not get the greenest country in the EU to prompt wind energy, Germany.

Sep 26, 2012 at 2:20 PM | Unregistered CommenterShevva

Mark Lynas - Well, at least we can agree that OCGT is not used to back up wind. So the Global Warming Policy Foundation's argument falls.

Which GWPF argument?

You seem to agree that "for the future things will be different". Nobody disagrees that variability/intermittency is less of a problem at low scales. But in Germany where there is a much higher penetration of renewables, there are problems with grid stability -- to the extent that industrial plants have been taken out -- and of extraordinary prices for domestic consumers who subsidise commercial/industrial consumers, to the extent that 600,000 homes are cut off annually.

Moreover, Grid CEO Steve Holliday himself says that the future of the grid is one which will not be able to provide energy on demand at certain times. Hence, we have a £12bn 'smart meter' plan, which will cope with problems of supply by reducing demand (switching your stuff off). The idea he has offered is that people who are less well-off will have supply contracts that are interruptible, similar to the contracts that are available to very large industrial consumers at present. Electricity at tiems of scarcity will be more expensive than at times of abundance. In other countries, the statutory requirement of generators/suppliers to provide a continuous supply of electricity is being reconsidered.

Arguing about the point at which the technical and economic problems of connecting an increasing number of wind farms to the grid develop seems to miss the point. Changes to the grid, to the generating hardware, to the relationship between consumers and producers, and to the way in which energy is paid for -- i.e. policies -- have proceeded without transparent debate. We can see what values inform those policies when we see government indifference to rising energy prices, its calls for £200bn investment in the grid, it's completely disingenuous calculations of cost to the consumer by 2020, its emphasis on 'behaviour change', its smart meter project, it's hollow promises to create 'green jobs', and its intransigence in the face of criticism. Keeping the lights on, and keeping electricity affordable are simply not policy goals of this or the previous/next government.

The people you met were on-message. Did you actually ask them any difficult questions?

Sep 26, 2012 at 2:30 PM | Unregistered CommenterBen Pile

Can I just say I think it's really great that Mark Lynas has stepped in here and defended his article. This actually makes for a much better quality of debate. Doesn't mean I am going to agree with him though!

"What no-one seems to understand is that the grid is balancing all the time..."

My earlier point was that you didn't seem to understand this - as the grid balancing is what you have been measuring not savings in CO2.

"This is not how a real grid works, like in the UK, ... including coal, nuclear, hydro (PS and non) and interconnectors ..."

I'm not sure this matters. The fairest way to do the comparison is to compare coal and nuclear or gas on it's own - with something else that can do the same job. Wind can't. The fair comparison is between, coal, nuclear, gas and 'gas+wind'.

From the perspective of the man at the National Grid the best kind of power station is hydro-electric. Turn it on when you want it, turn it off when you don't. And you can go from nothing to full power in about ten seconds. The second best power stations are nuclear, coal, and gas. Switch 'em on and leave 'em running. A poor third is wind which may be there when you need it or may not.

ow for a country with loads of hydro, wind is really quite attractive, when the wind blows you switch off the hydro and that means you have more water behind the dam for when the wind isn't blowing. But in the UK we need to have 1GW of gas for every 1GW of wind, and the best we can hope to achieve is about a 30% reduction in gas consumption - compared to just running the 1GW gas station 24x7.



Sep 26, 2012 at 2:31 PM | Unregistered CommenterNickM

When environmentalists support the large-scale development of wind-farms, I think they would do well to bear in mind the high land area requirement, with the consequent damage to the countryside. Again from MacKay:

This number is worth remembering: a wind farm with a wind speed of 6 m/s produces a power of 2 W per m2 of land area. Notice that our answer does not depend on the diameter of the windmill. ... Bigger windmills might be a good idea in order to catch bigger windspeeds that exist higher up (the taller a windmill is, the bigger the wind speed it encounters), or because of economies of scale, but those are the only reasons for preferring big windmills.

Given that the current total UK energy usage is 300 GW, it is easy to see that a very large land area indeed would be required for onshore wind to make any worthwhile difference. Even off-shore doesn't improve matters significantly, if this simply means a few miles from the coast.

Sep 26, 2012 at 2:35 PM | Registered CommenterPhilip Richens

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