By becoming more efficient we can save energy (and cash) as well as reduce the greenhouse gas emissions believed to be causing global warming. We currently waste a great deal of energy, so there’s lots of room to improve.
Take the example of personal transport: a four-seater, 35 miles per gallon (petrol or diesel) car wastes most of the energy in a gallon of fuel as heat. A good two-seater electric vehicle, on the other hand (by 'good' I mean 'perfectly practical and comfortable for urban and suburban driving'), can get a performance equivalent in the vehicle of around 280 miles per gallon, eight times as efficient as the conventional vehicle in our example. This is because electric motors are very efficient while running (almost no heat loss), don't run at all while a vehicle is in stationary traffic, and because the vehicle is smaller and lighter (similar to a common two-seater conventional car which thinks it’s 'smart' too).

However, the efficiency of electric motors over combustion engines only holds true if the electricity is itself generated efficiently. If we factor in the heat wasted by a conventional power station in providing our electric car with 'juice' we get a substantially lower overall mileage: around 90mpg. Even so, if as well as a 'caring, sharing society' we could become a 'car-sharing society' we could easily find solutions for long-distance journeys or for those occasions when a larger vehicle with more seats is required, and that’s before we even get on to the potential for better public transport in helping to lower energy consumption per passenger mile and ease traffic congestion.

In terms of technology, we can easily reduce our total energy demand, regardless of source, by 50 per cent without significantly lowering, and perhaps even improving, our standard of living. A renewable energy mix would include wind, solar heating and electricity, biomass, hydropower, and wave/tidal power. Onshore wind power could provide at least 25 per cent of future electricity needs. In Germany, one can find whole regions where the average electricity generation by wind is already at 20 per cent or above, despite energy-saving and transport having hardly progressed at all in the last ten years.

It is often alleged that wind power is inefficient and unreliable. Critics point to the machines' 25 per cent 'capacity factor' as evidence that wind turbines stand idle for three quarters of the time, but this is highly misleading. A single 1MW turbine can, in high enough winds, generate a maximum 1MW of power each second, but in the course of a year it will average around 250kW of output. No-one expects a car to do its top speed all time, so why expect a wind turbine to achieve its maximum output all year round? Besides, 250kW is still enough electricity to serve at least 625 homes, or 2500 individuals continuously, on balance, for the lifetime of a turbine (twenty years or so).

In the UK, predictions of energy supply and demand are matched up in 30 minute blocks a day in advance, a procedure known as 'booking' supply. Operators are used to dealing with sudden surges in demand, such as when the nation's kettles get switched on during the ad break in Coronation Street, and extra capacity in the form of 'hot spinning reserve', is kept running constantly, albeit inefficiently, in case of a sudden shortfall in supply relative to demand.

Of course, the wind doesn't blow all the time and we can't switch it on at will. What's more, the output from individual turbines and wind farms can drop away quite sharply, so there can be shortfalls here too. However, at a regional level, total generation fluctuations are much smoother, and variations from the wind power predicted a day earlier creep in slowly enough for any shortfall to be met by late-booking conventional power plant capacity; drawing on hot spinning reserve is therefore largely unnecessary (there is a need for a small increase in spinning reserve, but the energy gains from using a renewable energy source like wind still far outweigh the energy costs).

What could change, in my opinion, as wind power becomes more mainstream, is the amount of energy supply booked from any one power station at 'short' notice, i.e. within a twenty-four-hour period. Here false predictions do have a cost attached, but this is not a question of inefficient energy generation, nor is it inevitable. Many electricity suppliers stipulate in their contracts with industrial customers an agreed reduction in energy use by the customer for a set period in the near future in order to cope with peaks in day-to-day energy demand.

Ill wind?
True, we could never rely on wind turbines alone to provide for all our electricity needs. But there are storage technologies we can use, such as pumped storage hydro power schemes, where water is pumped and stored in an up-hill reservoir, thus acting like large batteries for the electricity system. This is just one of the options available to us.

Perhaps the issue that divides people most keenly is the visual impact of wind turbines. Personally, I find the occasional wind turbine can add to the beauty of the countryside, for example by highlighting a high point in the same way that a folly on a hill might do. They also give me a sense that my society is taking some its responsibilities to future generations and the world seriously. In Germany, where I live for part of the year, Sunday walks 'to the turbine and back' are very popular.
On a larger scale, I know of many examples of small and medium-sized wind farms where I stand and stare at the landscape, feeling the wind on my face, not quite sure of whether I approve or not of the change to what may once have been a pristine view. And then there are the mega wind farms, 'in my face' almost whichever way I turn, and giving me no rest. I can admire the power of these machines, but I don’t stay long. So I can quite understand the opposition to some people feel to wind farms 'in their back yards'. There are, sadly, examples of wind farms being sited inappropriately near to where people live.

Friends of the Earth believes that each project should be considered on an individual basis by the relevant planning authority and judged against planning policies that promote both renewable energy and landscape value. Local authorities should assess the potential for renewable energy in their areas and help identify sites that are appropriate for development. All significant impacts should be considered within a project environmental assessment. By consulting local people, avoiding the most sensitive areas, and careful siting, wind power companies can do much to ensure that turbines can be successfully integrated into our landscape.