A new study, commissioned by the U.K. government, reports that Britain has the best wind in Europe, since it blows throughout the year and hardest when there is the greatest demand for electricity. According to the report, there has been no time in the past 35 years when the wind has not blown sufficiently strongly (above 4 metres per second; that's 14.4 km/hr or 9 mph) to generate electricity in some part of the country. Graham Sinden from the Environmental Change Institute based at Oxford University said that the results were consistent that wind patterns over the U.K. were not random, but were clearly concentrated at particular times of the day. This is based on the hourly windspeed measurements taken from 66 weather stations since 1970.
Notably, wind-power is at its greatest during the day, and during wintertime, which is highly encouraging news for its proponents. Curiously, some of the "ayes" have commented that the survey's findings undermined one of the main arguments against wind turbines - that the power generated by them is "intermittent and unreliable." Well, it still is for any small group of turbines, and it is only when such inconsistencies in supply are averaged out over the complex scale of the national grid, that the variations begin to disappear into the baseline noise. However, the national grid is less efficient than localised micro-generation of electricity (and space heating for that matter), in view of the energy losses it incurs, and is one of the more cogent reasons for unshackling ourselves from our dependence on it.
The proposal of maximum supplyby wind at times of greatest demand sounds great, but is it true - or likely to still be true in the coming decades? As I type this is the early morning, I am feeling relatively comfortable, but as the sun begins to heat my back, I am reminded that we are experiencing a "very" hot summer. Quod erat, our demands for heating are ( it has to be said) currently minimal. And yet, there were power cuts in London last week, as demands on electricity supply were such that shops had to be closed, and some of the big, pricey stores are muttering about claiming compensation for lost business. Why? Because of the "need" for air conditioning units, sales of which are at a record high. It is often said that where America leads Britain follows (the "lag" seems to be about 10 -15 years, and closing, by my reckoning), and I am reminded of something I read recently to the effect that much of California's troubles with electricity supply (a thorn in the side of the "Terminator") are due to the massive scale use of air-conditioning units. So, it would seem hot British summers may well become more energy intensive, and hence it will not be unbridled wind-power that drives the electric heat-exchangers in these units. At home, so far, we have survived by simply opening all the windows and doors early on in the day, and for the most sultry nights, we find that a simple electric fan in the bedroom (both of us fitted with foam ear-plugs so that the whirr of its tiny turbine doesn't keep us awake) permits a reasonable night's rest.
The figures are a message in themselves. Louise Farrell, a spokeswoman for the national grid, said: "Last week, we informed the market (privatised power companies) that they needed to generate more electricity of use less because we were getting close to out safety margin, which we do not disclose." She said that on the hottest July day demand has been 44,000 megawatts (44 GW), which is higher than that for the hottest July day last year, by about 2 GW. Peak demand in winter is usually around 62 - 65 GW, but the gap is closing year on year. If a norm of hotter summers is to be expected, as some predictions of global warming indicate, then we shall need more electricity, and a more evenly balanced supply of it throughout the year.
As I wrote in "Wind Power - an Unlikely Question of Scale", the infrastructural implementation required to introduce wind-powered electricity on a national scale is stupendous, although it could be of great value in the form of more localised turbine units. Can this be reconciled with future demand? Can the energy-mix be finely enough tuned to draw benefit from various different sources of energy according to the wax and wane of the strength of each, to add up to a constant supply? And how will the underlying base-load be met? Presumably from gas, coal and nuclear, according to current government plans - this seems a certainty in the immediate couple of decades... beyond then, it is anyone's guess, but we are trying to draw more from a strained resource, which we are now seeing begin to snap.