Wind Turbines
The Royd Moor wind farm is well established and has even made it to Google Earth. It was up and running in 1993 with few objections and in fact looks impressive. At the time of writing this (July 2008), there are several plans for wind farms in our area. The Barnsley Chronicle (4th July '08) says that if current plans go ahead, there would be 27 wind turbines in a 5-mile radius of Penistone. A new action group has now sprung up: 'Protect Sheephouse Heights' was formed by concerned residents in Penistone and Stocksbridge who are worried about wind farms getting out of control.
The huge Cranberry turbines will have a visual impact for Penistone and the Peak District. For the first time in history, these man-made structures will be visible on the unspoilt bleak grouse moors to the south of Penistone. The Hartcliff Road end of the ridge is a popular beauty spot (picture below).
Blackstone Edge
The wind farm protest group CLOWT was formed in 2006 against the first item above for Blackstone Edge, near the Royd Moor turbines. Locals objected to it with more than 200 protest letters. That's a lot for the small community living nearby. Most of what follows refers to these turbines, using Royd Moor turbines as a point of reference.
Wind Turbine Output
How productive are wind turbines? Royd Moor's wind farm is a good example of a small-medium wind farm. As a rough guide, the thirteen turbines of Royd Moor can produce about 0.165% of Drax's maximum power output, in optimum conditions. It produces about 500kW power per turbine = 6.5MW under optimum wind conditions, which sounds a lot. The wind has to be not too high, not too low and not too gusty. On a still day no power is generated at all, not even enough to boil an egg.
Drax of Selby is the largest coal-fired power station in the country. It has a specified power output of 3,945 MWatts and energy output of about 24 TeraWatthour/year. One Drax would be about the same as 526 Royd Moors in power output under optimum conditions. But Drax has to meet demand at all times and vary output to meet demand. Ferrybridge and Eggborough power stations produce about 2 GW of power each. All three are visible from Royd Moor or Hartcliff on a clear day.
The calculations (for units, see below):
Royd Moor energy output (MegaWatts x hours) for a year = 6.5 x (24x365) = 56,900 MWh/yr = 56.9 GWh/yr. Multiply that by a fiddle factor for weather conditions and turbine 'down time'. I'll guess an optimistic 80% to arrive at about 45.6 GigaWatt hours per year (GWh/yr).Drax's maximum energy output (GigaWatts x hours for one year), 3.945 GW x (24 x 365) should be = 34.600 GWh/yr or 34.6 TWh/yr (untroubled by weather) but the specification says 24 TWh/yr, which must mean that it often runs well below capacity over the year (probably low output at night). So, comparing Royd Moor with Drax, we would need 24,000/45.6 = 526 Royd Moors or (526x13) = 6840 individual turbines in ideal conditions, producing 500kW of power each to 'equal' Drax's output. In fact, these figures are rather approximate and newer turbines are likely to be more efficient with larger turbine blades (given the planning 'push').
From the National Statistics Office, the national electrical energy demand in 2005 was given as 115,526 GWh/yr and will have gone up since then. If we had nothing but wind power working at full output, we would need more than (115,526/45.6) = 2530 Royd Moors or 32,900 individual 500kW wind turbines for our country - but preferably not all in our area.
Power Distribution
Most of England's power is generated in the north but most demand is in the south. It makes sense to build more generators in the south. There is a balance between the contribution of wind power to national requirements and environmental impact. By my reckoning, wind power is nowhere near enough to make a significant contribution unless it is done on a vast scale.
In any case, there is a limit to additional power contributions to the National Grid. According to the Lancashire and Yorkshire Renewable Energy Planning Study (pdf download) for the EU 'Altener Programme' (on behalf of BERR, formerly the DTI), the 'maximum opportunity for connecting new generation' for Yorkshire is limited to 600 MW from all power sources'. For the Sheffield area, with its demand of 1,529 MW, the 'approximate acceptable level of new generation' is less than 50 MW (on page 65).
Conclusion
Covering the country in turbines won't reduce the need for existing power stations, as full power must always be available, even on still days. I don't believe that they generate enough power to make a big difference but are a small 'sticking plaster' on the Global Warming' problem. Wave power is said to be more predictable and efficient but expensive to set up. Nuclear gives larger output but the problem of radioactive waste is far from solved.
Fossil fuel gas emissions from conventional power stations like Drax can be processed to reduce carbon emissions but are difficult and expensive to deal with. We are stuck with these power stations for a good many years to come. All things considered, wind turbines are really just a way of making money but they are also a bandwagon for politicians who wish to appear 'green'. My worry is that they distract attention from the real problem.
The national decline in heavy industry has reduced some peak demands for power but the population continues to increase one way or another and everyone needs heated homes and electrical energy for other uses. Nobody is interested in the root problem of - too many people on our overcrowded island! Meanwhile, China and India make our green efforts look worthless but we must persevere and do our bit, if only to shame the big polluting countries into taking it seriously.
Green Stuff for Homes
We should reduce power demand from the Grid with more energy-efficient homes, appliances and usage. The typical UK household is said to use about 4,500 KWh/yr but my own use is less than half of that. I have used low-energy light bulbs ever since they came out. The latest curly ones are very good.
Macrogeneration (small wind turbines and solar panels) can be useful in favourable locations but, according to a manufacturer interviewed on TV, only one in six houses is suitable. A domestic wind turbine might produce 500 kWh/yr. Photovoltaic ('PV') panels produce DC electrical power but I don't believe some of the figures quoted for our latitude and weather (Eg. '2,000 kWh per year'). They are very expensive to install and spare power to sell on is unlikely. Converting it to AC wastes more power. It is best used to pre-heat water. Well, you wouldn't use it for lighting, would you? Germany has a splendid system where houseowners are encouraged to generate enough power to sell it on to the grid. Power levels are limited but it is worth doing.
Water-heating solar panels raise the initial temperature of stored water, requiring less heating input from other supplies. They are actually useful, even in winter, but their control systems appear to be unreliable for some reason. If you visit Greece, you will find solar panels all over the place, although they have much more sunshine than we do. Water turbines on rivers and streams are worthwhile where practical and can generate plenty of useful power, some of which can be sold to the Grid. Geothermal heat engines look promising and can be installed in small areas of land but their efficiency drops off with time, as the thermal conductivity of the ground pipes declines.
Thermal insulation of houses will reduce household heating bills but I wonder if cavity wall insulation is suitable for some red-brick houses in our area, built with cheap and flakey London Bricks which are susceptible to frost damage. It might be better to let air circulate in the cavity, as intended.
Electrical Units
Power is given in Watts (W), kiloWatts (1kW = 1,000W), MegaWatts (1MW = 1,000 kW) and GigaWatts (1 GW = 1,000 MW = 1,000,000 kW).
Energy is Power x Duration of its use. On UK electric bills, it is given as 'units' (1 unit = 1kWh). Examples of burning a 'unit' (1 kiloWatt for 1 hour) are: running a 20W low energy light bulb for 50 hours - or - running a 4 kW electric cooking ring for 15 minutes.
Generator energy outputs are given in MegaWatthours per year MWh/yr, GigaWatthours per year (1 GWh/yr = 1,000 MWh/yr) and TeraWatthours per year (1TWh/yr = 1,000 GWh/yr = 1,000,000 MWh/yr).
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