The UK government has announced an intention to allow offshore wind farm development around most of the UK. John Hutton suggested that about 33 GW capacity could be added by 2020. This would provide about 25% of current UK electricity demand (which is itself rising by 1 to 2% per year).
Simple calculations suggest that this change may add about 15-25% to UK electricity bills. Offshore wind is more expensive to construct and operate than onshore wind farms. The announcement may suggest that the government believes that offshore wind can be pushed through but that onshore farms are likely to be successfully opposed. The big push for offshore wind seems to mean that the government is losing faith in nuclear.
***
The UK continental shelf is a good place to build wind farms. Wind speeds are high and the UK’s oil and gas industry has given us the capacity to work in harsh regimes. After a period of experimentation with smaller offshore wind projects, the 300-turbine London Array, shortly to be constructed, will become the largest marine wind farm in the world.
The government has given increasingly clear signs that it viewed offshore wind as a renewable technology of choice. It increased the proposed support from one ROC (currently worth about £45) to one and a half in the 2007 Energy White Paper. It now seems also to be willing to over-ride the Ministry of Defence’s concerns about the impact of wind farms on military radar. The worries over the turbines dicing small wading birds have been pushed aside.
The basic numbers
The government wants another 25 GW on top of the current 8 GW in various stages of planning. These figures refer to the maximum output of the turbines on a windy day. The actual output is likely to be between 30 and 35% of this figure. (Data from Scroby Sands, an early offshore farm, suggests a lower figure, but the turbines have suffered from reliability problems which have depressed the output.)
33 GW of offshore wind capacity will provide about 100-110 TWh, or perhaps 25% of total UK demand. This approximately equates to the electricity demand from households today.
When the wind is blowing hard, the total offshore capacity envisaged by Mr Hutton will almost match the minimum total demand during a winter’s day.
Total UK electricity demand (MW) in the 24-hour period to noon on Tuesday 11 December 2007
This chart is copied from National Grid real-time data. The y axis is MW. A GW is 1,000 MW. So the minimum demand on 11 December 2007 was reached at about 5am with a total demand of about 35 GW, about 10% more than would be generated on a very windy night all around the coasts.
If – and this is a very big if – the existing value of ROCs is maintained, then the possible subsidy from all electricity users to offshore wind if all 33 GW capacity is built is about £7bn. Over a year, this would raise the price of each kilowatt hour of electricity by about 1.8p, compared to the current retail price of about 10p. In addition, there will have to be substantial payments to other generators to incentivise them to build and hold ready gas-fired capacity for use when the wind isn’t blowing.
Offshore wind is expensive because its construction cost is high. The British Wind Energy Association mentions a figure of £2m per MW of capacity, compared to less than £1m for onshore wind. The total investment required to build 33 GW might therefore be as much as £64bn, about 6% of UK GNP. The BWEA figure looks a little high to me and the actual cost might be somewhat lower at perhaps £50bn.
The problems
The government’s announcement was broadly supported by the other main political parties. It is the easiest source of renewable energy to back, even though it is expensive. The ROC subsidy system disguises the true cost of switching to wind and other sources, so politicians must assume that the extremely heavy expense of wind will not be obvious enough to be politically dangerous.
The problems for offshore energy lie elsewhere:
- Turbine supply: only a small number of suppliers make marine-ready turbines. Vestas and Siemens, both based in Denmark, have made most of the ones already supplied. The worldwide shortage of top quality turbines is likely to persist for some years. New manufacturers will be enticed into the market if government support looks robust, but this could take the best part of a decade. Some of the existing turbines have severe problems with gearboxes (as at Scroby Sands) but we can expect these issues to be overcome eventually.
- Grid connections: powerful arrays of turbines must be located close to points on the high voltage transmission network. It is no good putting a hundred turbines 50km from the nearest point of interconnection unless you can be sure to get planning permission for the National Grid to run pylons. (I think I am right in saying that the substation to handle the electricity coming onshore from the London Array was the last part of the infrastructure to get planning permission.)
- Skills: the UK has offshore skills as good as most other countries, but getting 7,000 turbines built by 2020 is an extremely challenging task.
- Intermittency: offshore wind is reasonably predictable and strong. Below is the wind map from the BBC on the afternoon of Tuesday 11 December 2007:
In the southern portion of the UK coastline, wind speeds will be low because of the prevailing cyclonic weather. But further north, the west coast is seeing reasonable wind speeds. Days of real quiet are surprisingly infrequent. Nevertheless, if we are to generate 25% of our electricity from offshore, we will need substantial back-up capacity. Very approximately, the UK has about 8 GW spare capacity. By ‘spare’ I mean unused generating capacity above what is likely to be the peak on a very cold December day at about 5.30pm. We will need to have much more when we have 33 GW of offshore power. I haven’t yet seen an estimate, but I suspect that it will be at least 12 GW more than we have at the moment. The capital cost of the gas plant to deliver this is likely to be over £4bn. - The interaction with nuclear: it hasn’t been picked up by the press, but a 25% target for offshore wind is not easily compatible with a large nuclear industry. Nuclear needs to run all the time as baseload. If the wind is blowing strongly when demand is lowest (about 5am on a summer’s day) then the UK will run the risk of having too much electricity supply. Either nuclear or wind would have to be disconnected or the UK would have to invest in more of what is called ‘pumped storage’. Surplus electricity is used to push water uphill into reservoirs. The reservoir can be discharged later, turning hydro-electric turbines when demand is higher. It is difficult to encourage large amounts of both nuclear and wind, and the government’s new wind policy must mean that it is losing interest in nuclear.
The conclusion
Offshore wind is expensive and still somewhat untried. The government’s apparent decision to allow rapid development around a large portion of the UK coast is path-breaking. Most observers think that getting to 33 GW is an extremely optimistic target for 2020. However, industry people think that it may be possible to get as high as 20 GW, probably generating over 15% of UK power.
Tags: electricity demand, London Array, power generation, renewables, ROCs, Siemens, Vestas
-
“The big push for offshore wind seems to mean that the government is losing faith in nuclear.” You seem to ignore that the UK (like France) can export surplus nuclear-generated electricity to continental Europe and the means to do so already exists between the two countries. A premature, and likely false, conclusiion I am afraid.
-
Chris Goodall replying,
Dear Brendan,
Thanks very much for the note.
I accept that in times of low wind speed, we could use the Interconnector to import power from France. But there are two problems here. First, the Interconnector has quite limited capacity. We could upgrade it, but we would need EDF to want to sell to us, even though we couldn’t predict when we’d need the power. At the moment, the Grid can give EDF reasonable indications some hours/days in advance. This would be much more difficult with 33 GW of wind capacity. Second, we would still really need substantial ‘warm’ CCGT power, just in case French electricity was not available. Third, and I put this very badly in the article, nuclear power stations are run most effectively 24 hours a day as baseload suppliers. If we have a large number of nuclear stations, we will cover the minimum daily need for power (about 5am on a summer morning). So the wind turbines won’t be useful – their power will be surplus. My very badly expressed point was that if wind investors see a push for nuclear, they won’t commit and if nuclear investors see a lot of wind, they won’t put the cash down either. The two power sources don’t comfortably co-exist and in a fully liberalised market like the UK, if the government backs wind, it will find it troublesome to get investors to back nuclear.
-
You’re right – getting planning consent for the on-shore distribution network was a key delay in the London Array project.
On Brendan’s question of selling surplus electricity to France. The interconnect is currently used to move electricity both ways into and out of France. The published DTI data suggest we import a lot more electricity than we export. My conclusion is that there is capacity to sell more to the French since I believe the interconnect has the same capacity in both directions. How much capacity though?
It may be useful to look at the Danish experience with a high level of wind power in their supply mix. It’s reported (and I have to say I got this from a UK source who is against wind power on aesthetic grounds) that they do export a lot of power to neighbouring Sweden and Norway, when wind in conjunction with other sources produces more than national demand.
The UK’s move to a higher level of renewables was always going to affect the balance between supply and demand. In the same way that we are advocating diversity of supply sources within the UK to give energy security and better balance, we should be thinking about a higher capacity pan-European grid which would give diversity across the continent.
With intermittent generators like wind, the more you have in a network, and the wider the geographical spread of both the generators and the users, the easier in theory it is to balance supply and demand. The penalty is the higher cost of transmission and control systems.
I believe discussions have recently taken place in Europe on how far the existing interconnects between different countries should be enlarged. And there have been proposals for electricity to be imported from Iceland (geothermal I think) to Germany, and from solar thermal in Algeria to France / Germany.
If Chris, you believe that the Government’s stimulation of wind power on this scale hits the prospects for new nuclear, what does it do for the Severn Barrage?
-
wind farms are useful because they don’t produce polution
-
I would question the comment ‘wind farms don’t produce pollution’. The energy requirements for the construction of each turbine is not inconsiderable. Add to that the energy requirements of transporting the turbines across land to ports, loading onto barges, shipping them to site, off-loading and erecting and the pollution costs start to add up. There is no such thing as ‘pollution free’ energy production.
Solar power requires the manufacture of photovoltaic cells which contain hazardous substances. Even plant energy, although using ‘clean’ sunlight energy, makes use of fertilizers if grown on an industrial scale. ‘Organic’ farming utilizes manure which releases methane. Methane is a ‘greenhouse gas’.
So, it is wrong to promote any power generation as non-polluting. One has to consider the wider picture when choosing which form of generation to favour. The best way by far of reducing the pollution from energy production is to use less of it. More emphasis should be placed on responsible use of energy. Governments should show their commitment by introducing measures to force ALL members of society to become responsible energy users.
Planning laws can be used to compel developers to construct ‘carbon neutral’ homes and business properties. Every factory should be forced to become self sufficient in power generation, using roof areas for solar power harnessing devices, wind generators and pre-heated water supplies. Offices should use passive heating systems and geo-thermal heating. Minimum insulation levels should be increased, air-conditioning should be out-lawed unless run from self-generated non-fossil fuel sources. Minimum carbon emissions from cars, lorries, buses, taxis and shipping should be much more restrictive.
Public buildings should be forced to install low-energy lighting and, where possible, utilise natural light. Thermostats in such buildings, including hospitals, should be turned down to more realistic levels. Retail outlets should be forced to have street doors closed or have an internal chamber to prevent heat-loss.
We need to change the mind-set of energy users. It’s not a cost-free product. Energy will become much more costly as fossil-fuels begin to deplete. At present there is little incentive to adjust our profligate use of energy. Stringent action needs to be taken and soon. We have to make choices on an individual level and act in a way that forces the big energy users to reconsider their actions. Refuse to buy items that are over packaged. Send the junk mail back where it came from, unopened! Grow your own food where possible. Walk when practical instead of driving. Buy your kids a bike instead of acting as their taxi. Email your ‘paper-work’ don’t post it.
Think, don’t just accept the norm. Change your life-style and change the world. Don’t just think ‘green’, DO ‘green’.
-
@louise and jamielee,
wind farms are useful because they don’t produce polution
Did you mean to type, “pollution”?
Windfarms should be used only if they are competitive in the marketplace. Right now, they do not make money. They only make nutty environmentalists feel good about themselves. If wind farms were viable as an energy-provider industry, governments wouldn’t have to mandate them. State and local governments, as well as private entrepreneurs, would be building them everywhere and selling the electricity. I am all for any business endeavor that makes money for the owner/stockholders, but wind farms don’t do that yet, and governments shouldn’t be using taxpayer money to prop up technology that is inefficient just to placate the eco-religionists.
-
Hi i find your web site very interesting and full of useful info.
i have 3 wind generators/turbines and 4 solar panels my self and i run my 2 tvs and lights on them, so i am saving money and help to save the environment! I am also thinking to convert my car to run on water!
Regards Steve. -
The GB France HVDC link has a capacity of 2GW. There are also connectors to Northern Ireland (500MW) and the Isle of Man (40MW). Finally, there’s a GB Netherlands connector of 1GW under construction, and proposed links to Norway (1.2GW) and Eire (500MW). (Eire and Northern Ireland are also inter-connected to each other.)
Ads by the Guardian Green Ad Network
9 comments
Comments feed for this article
Trackback link: http://www.carboncommentary.com/2007/12/12/62/trackback