Why treating wind energy as a national – and not a continental – resource limits its effectiveness and opens the door to critics of the technology.
Most endeavours in renewable energy, in Northern Europe, began with wind energy. Wind turbines were small. They were local, in that they were connected to the distribution wires. They made little impact on the electricity system. They were strictly seen as an environmental contrivance. They produced electricity without CO2. They had few of the characteristics of a power station. Then as now they were connected to existing grids, which were built for another purpose.
As wind machines got bigger they began to evolve. They began to look more like power stations. This effect was demanded by the operators of the transmission grids, to which wind machines were increasingly being connected. They were required, by those operators, to meet additional standards such as being able to stay on load during a fault on the electrical system. They had to be redesigned to have “fault ride through characteristics”
The average size of wind turbines went from a small percentage of a megawatt, to the current average of circa 2.5 megawatts. Those arguing in favour of wind energy still saw them as contributors to a better environment, viewing them as deliverers of CO2 emission reductions first, and generators second. Wind turbines were designed to be deployed quickly in place of fossil fuel plant. For good reason, rapidity of deployment and reliability won out over experimenting with more optimal designs. Thus, most wind turbines still shut themselves down at wind speeds of 25 metres per second. It was argued that the wind speed exceeded this parameter only one % of the time. Little consideration was given to the fact that during a storm 25 m/s was exceeded over a large area. The speed occurred only one % of the time but it occurred this one % all at the same time. I have seen wind energy in Texas shut down 4000 megawatts in 4 hours, as a big storm rolled in. Wind generators were failing to capture the full potential of the wind, and critics began to argue that they were unreliable.
The politics of wind was local as well. Each country formulated its own response to the environmental challenge. Targets for wind penetration were set for each country. Even when wind energy began to be seen as a contributor to electrical generation, it was seen as that nation’s response to rising oil coal and gas prices. In Europe the sum of the nations were added up to give a European total. In the meantime the grids remained fundamentally national in character. 90% of generation is consumed in the country where the generation happens. Those promoting wind energy organised themselves along national lines. Even European bodies like the European Wind Enery Association (EWEA) are in effect an amalgamation of national representatives. Its Board is structured so that in effect power will, in extremis, rest with individual nations.
Wind is variable in output. This is particularly so at any one locality. Take for instance the recent report of the Fraunhofer Institute in Germany, as reported in Reuters by Gerard Wynn. Variability of installed solar power in Germany as measured by the standard deviation shows an average weekly solar output of 635 gigawatt hours with a standard deviation of 289 gigawatt hours. For wind the average weekly output is 843 gigawatt hours and a standard deviation of 480 gigawatt hours. This is very variable output.
Some bare recent facts are these: - There are 30,000 megawatts of wind installed in Germany, and there are 25,000 megawatts of solar pv. In 2011 this plant delivered 11% of the consumed electricity in Germany. However, during an anti cyclonic spell in February 2012, 22,500 megawatts of natural gas were required because of low output from this wind and solar plant.
This is not to accede to the criticisms of the technology by those who would rather we continued to burn fossil fuels. Rather, it is a recognition that treated as a source of national power generation, rather than as a continental one, wind has its limits. In countries like Spain and Germany, those limits are being increasingly exposed, and the whole industry is being damaged as a result.
The opportunity created by this reality is to push hard for the opening up of Europe’s national electricity networks to competition of supply and the trading of renewable energy. Electricity supply is the largest public good not part of Europe’s single market. If we are to fully decarbonise our power sector, and dramatically reduce our carbon emissions, while limiting the seemingly inexorable rise in consumer bills, we need to fully capture the value of our wind and solar resources across a European market.
For example, further investments in Germany in the renewable energy space ought to be in profoundly connecting up that country’s grids with the UK. The same reserve gas plant could almost service the two markets. When a storm arrives in UK, and the wind output is full on, spare wind power can be routed to Germany, and vice versa. It is extremely unlikely that an anticyclone could cover Germany and the UK at the same time, so instead of using inefficient gas in Germany to replace the non performing wind, much more efficient gas plant in the UK can be used for cover. It should be remembered at all times that the marginal cost of wind energy is zero.
One of the issues that we ought to be concerned with, as proponents of wind energy, is the charge that for every megawatt of wind that is installed a megawatt of new gas plant has to be built as well. On top of this it is recognised that the new gas plant will have a low capacity factor, being only needed when the collective wind output is very low. Capacity payments to have gas plant available when needed will be significant. The megawatt hour price of this little used gas will skyrocket. So the combined price of an additional unit of wind and scarcely used gas is now no longer zero. Renewable energy installers lose one of our key commercial selling points (zero marginal costs). If we leave things as they stand, as in Germany, this is the situation that will come to pass.
Wind deployed in any nation is great up to a point. That point occurs when either one of two conditions apply
1. The grid becomes “clogged” with non controllable wind, and the output has to be constrained. From this point on no new wind will be built.
2. A country becomes over dependent on wind and needs the kind of backup that we have seen happen in Germany in February.
This I believe points us in the direction we need to travel if we are going to decarbonise our electricity industry.
• Wind is more effectively deployed on a continental basis rather than on a national basis
• As the wind is always blowing somewhere, its variability gets smoothed out by collecting it over a wide grid
• Reserve fossil generation supplies can be shared between nations
• A whole new industry, based on extensive trading of electricity, will be created.
• The winner in this continental wind deployment is the customer. This is so because:
o Collectively all nations can go to higher penetrations of wind
o The marginal cost of this wind is close to zero
o Reserve plant is shared, and so the cost is reduced
o There is much more competition in the supply of electricity, as many more players bring trading skills to bear
For this continental approach to renewables, Europe needs a single market in electricity, and to deliver that market we need the Supergrid. There can be no transition, without transmission.