Wind power's not intermittent, honest!

[An Inspector Calls]

Well, it was only a matter of time, but this is the latest idiocy the UK will have to buy into to support wind power.

http://www.energycentral.com/functional ... d=20571684

Britain's richest energy companies want homeowners to subsidise billions of pounds worth of gas-powered stations that will stand idle for most of the time.

Talks have taken place between the Government, Centrica, owner of British Gas, and other energy companies on incentives to build the power stations needed as back-ups for the wind farms now being built around the country.

It is understood 17 gas-fired plants worth about UKpound10 billion will be needed by 2020. The Energy Department has been warned that without this massive back-up for the new generation of heavily subsidised giant wind farms, the lights could go out when the wind dies down.

Sam Laidlaw, chief executive of Centrica, said renewables, such as large-scale wind energy, were intermittent and required back-up generation, a role gas was uniquely qualified to fill.

But as power stations that operate only intermittently would not be financially viable, Laidlaw said: "The building of new gas-fired capacity must be incentivised so that gas can fulfil its role as a bridging fuel."

To that end, energy companies are asking the Government for "capacity payments." This ensures firms are paid a fee all year round for keeping a plant on standby. As in previous subsidies, homeowners would be asked to pay for them through yet another levy on their fuel bills, which are already expected to soar by up to 20 per cent this year alone. The Department is considering the request from energy companies and an answer is expected in a new energy White Paper due later this year.

Industry sources insist the Government has no alternative but to agree to the "capacity payments" for standby generation if it wants wind power, which also receives huge subsidies, to provide one-third of Britain's energy needs.

In winter, when the most intense cold period coincides with a high pressure front, most wind turbines do not work.

One industry executive said: "Why would we build a power station -- costing about UKpound600 million -- that is guaranteed to make a loss because it is not used most of the year?"

By 2020, most of Britain's nuclear plants, old gas-fired plants and coal-fired power stations will be closed, leaving a 30 per cent energy gap to be filled by more new nuclear plants and more wind power.

British Gas managing director Phil Bentley has warned prices will have to rise by at least 15 per cent to compensate for the soaring cost of wholesale gas. Meanwhile the oil price dropped again on fears over the global slowdown.

[goslow]

Well. What happens currently with gas plant that are kept ready to fire up to meet unexpected demand? Do they get special payments?

Having gas plant ready to smooth out the ups and downs of wind energy seems necessary in the shorter term. Longer term there is time to develop more elaborate and low CO2 approaches, including gas-CCS, biomass, supergrids, demand management, pumped storage....

[An Inspector Calls]

Gas plants will seldom be on standby to generate on an 'emergency' basis. Most of the response and reserve load of our grid is met by the PS stations and coal generators on part load. If they have to put CCGTs on standby it'll increase the maintenance costs of that plant markedly. gas-CCS will be no more nimble that ordinary CCGTs.

Payments for response/reserve now: generators participating in the market get a proportion of the pot put aside for ancillary grid services (response/reserve) and that's it. The pot is/was last time I looked targeted to be £250m a year. At the moment, it's a small market.

The demand side management of the grid is viewed as being saturated. NGT have contracts with all the big loads that can tolerate outages such as steel and Al producers.

You'll need a vaste amount of PS to manage the planned wind capacity - I doubt you'll find the sites to do it. And remember they're expensive to build and only 75 % efficient.

[goslow]

OK. Its a bit annoying if coal is being used on part load, gas would be much more preferable. But the talk is definately towards gas being used for this purpose in the future. The financial mechanisms to make that viable business-wise can't be too hard to organise either, developed from this existing grid services pot?

[An Inspector Calls]

The ancillary services pot is a piddling £250m!

If we build 30 GW of intermittent, variable output wind, capacity credit ~5 %, we'll have to build 29 GW of gas turbines. Even at a very conservative build cost of £500k/MW, that would be £14.5b, requiring replacement every 20 years. So that's an annual capital expenditure of £725m. Then we have to staff and operate the plant. If we assume £20m/GW for that, we have to add another £290m. And we're still not finished with our expenditure. We need to buy fuel, run transmission and gas links, and cover services to the gas plants such as rates.

If we need to mix in some PS to provide primary and secondary response (I've never heard of gas plant providing these services) then the costs will escalate further.

The question of whether this is economically viable for Britain has to be asked.

[clv101]

The question of whether this is economically viable for Britain has to be asked.

A more interesting question is just what "economically viable" means in a world of increasing fossil fuel scarcity, the potential end of conventional economic growth, future currency and commodity valuations highly uncertain and legislation being discussed regarding whether Europe's emissions are to be cut by 20 to 30%.

It's quite likely that nothing we can do today is economically viable by the old standards. It's also possible that the kinds of things that made a lot of sense in the past, aren't the best way forward now and things that haven't made sense in the past and by some metrics still don't make sense today are in fact the least worst option.

From a risk management point of view, it's probably a good idea to minimise our reliance on imported oil, coal and gas. There's significant uncertainty about the future world export market and about our currency's future purchasing power.

[goslow]

yes, I wrote "developed from the existing pot". Going from £250m to ~£1 bn seems reasonable to me, considering all the other big changes we are making.

Also, we could use some of our existing gas plant, and its not just NG that can be used, interconnectors and demand management are already coming into play.

Eventually, we'll find a way to manage without burning natural gas. Though small scale biomass, landfill gas, sewage gas etc is dispatchable and I am guessing suitable for balancing wind energy. Plus all the other solutions we have discussed.

However, fact remains that National Grid stated that the additional costs of managing wind variability are not significant up to 40% renewables.

[An Inspector Calls]

All high level stuff. And yes, it's all technically possible albeit I think the amount of biomass we have at our disposal might be just a tad more limited than the amounts of coal and gas.

Just so long as we realise that the 'we' in these statements is not some abstract body like the government, or 'the UK', but you and I and all the other energy consumers. There's little point in configuring this and that subsidy or energy payment when in the end the energy bill comes all the way back to each and everyone of us. And I get the feeling that there's not much extra cash around.

[goslow]

Absolutely, its us that pay in the end, though hopefully seeing a benefit in reduced external costs (environmental damage) and energy security.

There is a lot of profligate energy use that can be cut out, if necessary to mitigate increases in the cost of electricity for households.

[RenewableCandy]

The question of whether this is economically viable for Britain has to be asked.

...along with the question of what a better alternative might be, or indeed how "economically viable" it might be to carry on as we are and end up outbid for increasingly-expensive NG, coal and oil by other countries with more economic or military clout than we can ever hope to muster.

To draw a rather drastic comparison, was it "economically viable" to ignore Mr Chaimberlain's piece of paper and put up a fight?

[An Inspector Calls]

At least we have now established in the minds of those that set our energy plans(?) the fact that wind is intermittent and has little or no capacity credit. It requires conventional plant built as mirror, back-up generation for times when there is little or no wind across the UK or much of Europe.

It will also dawn on those same people that if the generation cover is to be part-loaded fossil-fuel plant, then that plant will run at efficiencies well below the same plant when fully loaded. This has the double whammy of increasing costs and reducing whatever pitiful fuel import benefit installing wind power was supposed to bring.

Then it might be the time for Churchillian rhetoric as a substitute for what should have been sensible economic analysis of energy policy.

And next: eyes down for the revelation that wind gusting and surges will almost certainly cause coincident windmill overspeed tripping and thus increased ancillary service response requirements. Another reduction of the fuel saving benefits of wind power.

[goslow]

The sensible economics point to using more renewables and less fossil fuel. We have burnt most of our UK fossil fuels and should not aim to rely on imported fuel. I am happy to have some thermal back up for wind at least in the short term, much of which can come from existing plant. The national grid can work out how much is required for that, its not 1:1 as far as I have gathered.

Its been pointed out before on this forum that there is often a tension between maximum efficiency and security of supply. You see the same in many areas, like choice in the NHS for example. Same for energy supply.
In the same way that in my home I have both gas boiler, wood stove (and maybe one day solar thermal). I duplicate capability which is not strictly the most efficient approach, but its what I want to do. In fact the wood stove is partly there in case of power cuts or gas price hikes. I could have not installed it and maybe saved money by just relying on the gas boiler, but there is a risk in that (as well as increased carbon emissions!).

I am not a wind industry engineer so cannot comment on this idea of gusting being a problem. There may well be some complexities (even problems) to manage as we develop this sector, but this is the same for any industry.

[An Inspector Calls]

I am happy to have some thermal back up for wind at least in the short term, much of which can come from existing plant. The national grid can work out how much is required for that, its not 1:1 as far as I have gathered.

Well, there's plenty of evidence pointing to the fact that the capacity credit for wind is very low:
http://www.publications.parliament.uk/p ... /19507.htm

As a result, the proportion of renewable generation which can be relied on at peak demand is much lower than for fossil fuel plants and more complicated to calculate. We received several estimates of how far wind capacity could be counted on to contribute to meet peak demand—its "capacity credit". BERR uses a range of between 10% and 20% of wind stations' capacity, so that 25 GW of wind plant could displace between 2.5 and 5 GW of conventional plant (Q 483). E.ON suggest that the capacity credit of wind power in the UK should be only 8% (p 119).

http://www.windbyte.co.uk/dnloads/SBCEnergyReport.pdf

Some renewable technologies can provide reliable power with a high capacity credit. Tidal systems and biomass are good examples, but under the Renewables Obligation these technologies offer developers significantly lower margins than wind-power, and consequently the focus at present is almost exclusively on wind, and mostly onshore wind. Unfortunately, the ‘capacity credit’ or ‘substitution capacity’ of wind power is very low.7 The CEO of E.ON-Netz, one of Europe’s largest grid operators, and one of the world’s leading authorities on the management of large wind capacities, points out that, “during periods of calm or storm related shutdowns, traditional power station capacities must be available as a reserve.” E.ON-Netz cites two independent studies that reached the synonymous conclusion that the more wind power capacity is in the grid, the lower percentage of traditional generation it can replace. Recent experience shows that Germany’s very large wind installation can currently only guarantee with reasonable confidence 8% of its total installed capacity. If as forecast wind power capacity is increased to 48,000 MW, the capacity credit would fall to only 4% of the installed capacity of wind.8 In other words, as E.ON Netz puts it quite explicitly, 48,000 MW of wind (ca. 24,000 modern turbines) would replace just 2000 MW of conventional generation, the equivalent to two medium-sized coal stations.

There's a downward trend in estimates of wind capacity credit; the more data is accumulated for the present wind fleet, the further it declines. The latest reports of Stuart Young now suggest it may well be 0%.

[goslow]

Thanks for those links. A quick look at the parliment report has in bold

The need to part-load conventional plant to balance the fluctuations in wind output does not have a significant impact on the net carbon savings from wind generation.

and

Our calculations suggest that the total extra annual cost of increasing the share of renewables in electricity generation from 6% to 34% in 2020 would be £6.8 billion or an extra 38%—the equivalent of an extra £80 a year for the average household.

I think that is manageable!

It would be nice of course if we can shut some thermal power stations but for me this is not a critical benefit from wind turbines.

As I understand, Stuart Young is an anti-wind lobbyist so I would treat his reports with some critical analysis.

[An Inspector Calls]

Well, the links do point to the fact that if we require security of supply, then we will have to match wind capacity one for one with backup capacity - in effect, a double build. This has a huge impact on capital costs of a wind strategy.

I'm not aware of a detailed study of the effects of running part loaded plant to cope with wind variability - it would depend on the plant mix constructed alongside the wind fleet. It depends what they mean by 'significant impact on the net carbon savings from wind generation'; my informed guess would be that the savings will be reduced to 75 % of what they would be with no back-up.

And

Our calculations suggest that the total extra annual cost of increasing the share of renewables in electricity generation from 6% to 34% in 2020 would be £6.8 billion or an extra 38%—the equivalent of an extra £80 a year for the average household.

is now out of date. Only yesterday, in the ST, were there projections of a doubling of energy prices by 2020.

Stuart Young is, indeed, an anti-wind lobbyist. However, you can't despatch his report that easily since the data he uses are public domain and therefore his entire analysis can be reproduced by anyone wishing to counter his claims. No one has done so. And indeed, you only had to look at this winter's balancing market plots published half hour-by-half hour by Ofgem to see that the wind fleet had 'disappeared' for a fortnight around Xmas 2010.