Wednesday, February 13, 2008

UK May Struggle to Meet Energy Demands.

A report concludes that within 5 - 7 years, the UK may face a gap between supply and demand for its electricity. According to the firm Inenco, which offers consultancy on energy and environment issues (as do I for that matter), the number of nuclear and coal fueled power stations that are due to come out of service within this period is likely to cause power shortages. In contrast, other analysts think that new plants can be constructed in time to avert this unwelcome outcome. My understanding is that it takes around 10 years to build a coal-fired plant and 15 years for a nuclear power plant, and so the latter conclusion might appear optimistic or touch and go, at best.

Inenco think that the crunch will hit some time during 2012 and 2015, which coincides nicely with the expected arrival of peak oil. Coal-fired plants have been running more than previously expected as a result of increased gas prices, and their operating hours are limited by EU legislation intended to limit pollution e.g. from SO2. The latter states that such plants built before 1987 must be either fitted with contemporary emissions control equipment or they can only run for a maximum of 20,000 hours between 2008 and 2015, by when they must be withdrawn entirely from service. 20,000 hours is roughly 2 years, and the old unmodified plants are likely to use-up their quota sooner than was planned, resulting in their closure becoming more immediate.

The most obvious means to fill the generation-gap is to build new gas-fired stations, but potential investors may be unwilling to put their money into them when nuclear power has been given the go-ahead, and is considered by some to be the more favourable technology, ultimately. Even if we re not bedevilled by power cuts, there is little doubt that electricity prices will rise in the years to come.

On the subject of coal-fired powered stations, I note that the UK government is anticipated to approve the construction of a facility without insisting that it adopts carbon capture and storage (CCS) equipment. This does not surprise me since I noticed an off-the-cuff mention in the recent report about the future of nuclear power in the UK, which overviewed the various issues of energy provision, that CCS technology may not prove viable, in its final actuality. I have seen figures to the effect that it would take about 20 - 40% of the energy output from a coal-fired power plant to implement CCS, meaning that a third power plant would need to be built to cope with the carbon emissions for every two new ones that were so installed, hence it is not a trivial matter.

The new plant is to be situated in Medway in Kent, and there rests the proviso that it might be fitted with CCS in the future. Given the present state of the art for CCS which has no immediate reference for use on a commercial scale, I wonder of it will ever become a feature of coal-powered stations. China, for instance, a nation which opens a new coal-fired station each week does not use CCS, it should be noted, despite using more coal than anywhere else. According to Greenpeace, seven other plants of similar size or larger are expected, which will not ease Britain's way into its commitment to curb its carbon emissions to 40% of current levels by 2050. I suspect by then, CO2 emissions will be the least of anybody's worries and they will be cut anyway by the shortage of fossil fuels, including coal.

Fires in coalmines are well known and some can rage unsubdued for years. In the classic "Miller's Elements of Chemistry", said author describes how a fire in a mine at Clackmannan in Scotland, which had burned for thirty years, was extinguished in the year 1851 by filling it with 8 million cubic feet of a mixture of CO2 and N2 produced by forcing a stream of air through a furnace filled with red-hot coke. The seam of coal was 9 feet thick and extended over an area of 26 acres. It was necessary to maintain the stream of gas for three weeks after the fire had been put out in order to cool the coal-mass so it did not simply re-ignite on returning air to the mine workings. To assist the cooling, water was blown-in as a fine spray with the damping gas.

More recently, in China, a fire was put out that had burned in a mine for over 50 years. The mine is at Terak in Xinjiang, described as a sparsely populated, mainly Muslim, area rich in natural resources. The procedure adopted was to drill into the mine and pump in a mixture of water and slurry, and then to cap the mine-shafts to exclude oxygen. The fire is believed to have consumed 12.5 million tonnes of coal and emitted over 70,000 tonnes of toxic gases per year since the 1950's. In addition to curbing this further toll on the environment, at least 651 million tonnes of coal have thereby been saved.

Related Reading.
[1] "Coalmine fire put out after half a century", By Jane Macartney, Times Online November 22nd 2007.
[2] "Miller's Elements of Chemistry, Part II. Inorganic Chemistry", John W. Parker and Son., London, 1856.
[3] "Britain 'facing energy shortfall'", By Richard Black, BBC News.
[4] "Energy firm wants carbon freedom at new coal plant", By John Vidal, The Guardian.

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