Although people are talking about global warming and climate change, not many know that Britain has an energy trouble in just a few years. The first reason is that we have transfer form self-sufficiency in energy to a net energy importer in a generation. 60% of coal and 10% of gas are imported. Even oil which we had much for years is also from other country. Gas is used more than anything such as generating electricity, cooking, heating our homes, and powering industry. It is said that by 2010, 80% of gas will be imported.
In October 2006 a new pipeline from Norway was commissioned; big enough to supply 20% of the UK’s requirements. Other imports come from Algeria in tankers, or by pipeline from the Netherlands, Germany or Russia. Russia has the biggest reserves of gas in Europe, and by 2020 it will be the principal supplier to the UK and other EU countries. In January 2006 Russia was in dispute with Ukraine and cut off its gas. In fact, the pipelines to Hungary and the Czech Republic go through Ukraine, so Ukraine solved the problem by cutting off those countries and keeping their gas for itself. Britain is at the far end of the pipeline, and any problems in between us and Russia could cut off our gas. Britain’s power stations are aging and nearly all will need to be replaced by 2020. At the moment the generators seem to be dragging their feet until they see a clear government policy on energy pricing, carbon taxes and carbon trading. In the mean time they work on extending the life of existing plant and hope that it does not get less reliable as it gets older.
What’s the alternative? What about wind?
There is a plan to build the biggest wind-farm in Europe on the island of Lewis in the Outer Hebrides. Lewis Wind Power has applied to install 234 turbines, which will provide 702 MW, about the same as a small power station. By comparison, the Sizewell B nuclear station produces 1,188MW and Drax, the UK’s largest coal-fired plant, produces 4,000 MW. Wind power cannot produce a constant supply of energy at every hour of the day. We can still be sure that the wind will blow on average for a given number of days each year, and the amount of energy that can be harvested is considerable. The wind is free, and it’s not controlled by anyone else. The Lewis wind farm could produce about 1% of the UK’s electricity needs – when the wind blows.When it doesn’t blow there needs to be other generating plant available to meet demand. Managing the grid – balancing demand and supply – is a highly skilled task. Demand fluctuates but output from conventional power stations is relatively steady and predictable. Output from a wind farm is less predictable, making the balance more difficult. If wind accounts for 3% or 4% of capacity as at present, fluctuations can be absorbed by using other generators. Much more than 10% and the whole grid will be hopelessly unstable.All this assumes the project will be built, but there is much local opposition. They object to the 234 turbines, 140m high with rotors describing a 100m diameter. They object to the 35 mile run of 141 pylons, each of which will be 27m high. They object to the 104 miles of new road, the nine substations and the control building. Once the power is brought ashore, there are objections to the 50-mile pylon route through the Highlands. If the objections are overcome it will probably be ten years before we can reasonably expect the electricity to flow from the Lewis Wind Farm. Supply shortages are predicted as little as 3 years from now.
A windmill on your roof
Why not put a windmill on your roof at home? You can generate your own electricity and if you have a surplus you can sell it back to the grid. You even get a grant from the government. Unfortunately there are problems and a domestic turbine is very unlikely to save you money or produce a worthwhile amount of electricity.
There are several domestic turbines available from £1500 installed and rated to save you about 30% of your electricity bill. For a typical home that is £300 per year, so the unit pays for itself in 5 years and after that it’s all profit. In fact, most turbines produce their rated output at wind speeds of around 12 metres per second, but if you go to the DTI’s wind speed database, which is searchable by postcode, you will find that the average speed for most of the British Isles is little more than half that. A turbine running at half speed produces a lot less than half its rated output.
Siting is another problem. Manufacturers recommend that a turbine should be installed in a clear, steady airflow, well away from buildings or trees which cause gusting. In gusty conditions your turbine will not produce its full output and is likely to wear out more quickly. Your roof top, especially in town, is not a good location!
If you are not at home to use your electricity it’s difficult to store but you can sell it back to the grid. However, the price paid is about 5p/unit or less than half what you would pay to buy it from your electricity supplier. Your payback time will be extended.
You will save more money, more electricity and more greenhouse emissions by upgrading insulation and buying low-energy light bulbs, than by installing a turbine on your roof. Wind power is not a solution to Britain’s energy gap. Be prepared for blackouts!