§ Mr. Hilary BennTo ask the Secretary of State for the Environment, Transport and the Regions what research his Department has carried out into the contribution that the use of solar power in domestic dwellings can make to reducing energy consumption; and if he will make a statement. [108020]
§ Mrs. LiddellI have been asked to reply.
The Department of Trade and Industry (DTI) has funded a considerable amount of research into the exploitation of solar energy in the UK. This research can be divided into three technology sectors: Passive Solar Design—the direct use of solar heat gain and daytime light in buildings to display conventional energy demand—Solar Thermal Hot Water Heating—to displace energy from other conventional heating sources—and Photovoltaics—which produce electricity from the action of daylight on photovoltaic cells.
To date most of the DTI funded PV research has focused on issues which are common to all applications of PV in buildings, and to research into aspects of PV integration into larger non-domestic buildings. The 107W potential contribution that PV can make to UK conventional electricity demand has been estimated in "New and Renewable Energy Prospects for the 21st Century. Supporting Analysis. March 1999. ETSU R-122". This gave a theoretical estimate of around 270 TerraWatt hours a year (TWh/yr) if PV were installed on all available walls and roofs for the entire building stock. More realistically, if PV were to be installed on all south-facing roofs and facades this would yield an annual output of around 70 TWh, or a little over 22 per cent, of current electricity consumption, which stands at around 324 TWh/yr. Obviously, if we are looking only at the roofs of domestic properties, the theoretical potential would be proportionately less. Installing 2 kW systems on 50,000 homes would cost around £500 million at current prices, but would generate less than one half of one tenth of 1 per cent, of current UK electricity demand.
In the short to medium term, up to 2010, the installed cost for PV on dwellings is expected to remain a major barrier to faster deployment of the technology. However, costs are expected to continue to reduce, and a market for domestic PV should develop accordingly, so that in the longer term PV has the potential to make a significant contribution to reducing energy consumption and carbon emissions.
The DTI funded a demonstration project for a domestic PV roof in Oxford in the mid to late 90s. The 4 kW system cost in the region of £25,000, and showed that, over the year, output from the system could match demand from an energy-efficient home, with surplus electricity generated by PV during the day, particularly during the summer months, being exported to the grid, and being balanced by imports during the night and winter months.
The DTI is contributing £1 million towards a field trial looking at the implementation of PV on clusters of domestic dwellings. It is hoped this will result in total investment of £2 million and the installation of PV systems on two to three hundred dwellings. Other ongoing work within the DTI Solar Programme is investigating the development of PV systems for domestic roofing.