Tuesday, September 25, 2007

Nuclear vs solar water heating and carbon impacts

New nuclear build is carbon lighter than fossil fuels but not as light as some renewables.

All renewables have a carbon impact, but it varies enormously from technology to technology. For example, much electricity is used for water heating. Solar water heating has negligible carbon emssions associated and can provide 30-50% of hot water over a year, depending on the location and orientation.

Electricity is used for space heating, and so is gas. Again, with new buildings, passive solar designs and high efficiency can reduce to almost zero the amount of fuel required. Heat pumps can triple the value of the energy input.

Figures from the LCBP show solar water heating was by far the renewable energy installation of choice for householders obtaining this grant. At the end of May, the figures showed that since it launched in April 2006 the LCBP has directly funded 2175 installations on homes, including 1467 (over two thirds) solar thermal heating systems, 313 (14%) solar PV projects and 242 (11%) mini-turbines.

That proves its popularity and effectiveness. The Energy Act should make it mandatory that all new buildings install this technology, and set retrofit targets. But as far as I can see it doesn't even mention this technology.

Space and water heating counts for 83% of domestic energy use (BNDH12, quoted in EST's Rise of the Machine, page 14) and about the same for office use. Together, offices and homes account for around 35% of UK energy use. Ie, 28% of total UK energy use.

Providing 40% of this by passive solar, solar water heating, heat pumps, domestic CHP, and woodchip/pellet boilers, would account for a significant proportion of the amount of power requirement as that required to compensate for the loss of old nuclear power stations.

It would have almost as great an impact in a shorter time scale and far cheaper but with little environmental impact than building new nuclear power stations, as well as creating more, sustainable jobs.

The above forms my answer to question two of the government's nuclear consultation

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