Sunday, May 20, 2007

Pay people for the power they provide!
Donnachadh McCarthy is a micro-generator, green consultant and former Liberal Democrat federal executive member. In 1997, before it was fashionable, he installed solar panels on his South London roof. (Though the illustrations are of local solar heating and generating installations.) He has since added an experimental wind-turbine.He calculates that he will never have to pay for energy again and is even able to recoup some of the cost through a deal with EDF Energy. Donnachadh receives from them 7p per unit for electricity generated which he does not use. Thus, he was able to bill them for £45 last year. At the retail price of 11p, he reckons to have made a further saving of £55 annually.However, he paid over £13,000 for his solar panels and wind-turbine. Even with a government grant, he reckons that it will take between 90 and 120 years for him to pay back the capital cost of the system.Some UK energy companies will pay the full market price for micro-generated electricity, but charge the customer for the installation of the export meter. This could be £100 or more.The German government compels its energy companies to buy back from consumers at a far more generous rate. That could account for the fact that there are over 300,000 installations of solar panels generating electricity in Germany. The UK equivalent is 5,000.The Labour MP (and at one time a challenger for the deputy leadership of his party) Alan Simpson chaired a recent symposium at Westminster. Simpson is an enthusiastic micro-generator, but only receives 40% of the market price for his exported electricity. German customers get four times the market price. Simpson calls for a similar deal for UK consumers, guaranteed over twenty years.The capital cost of solar panels has come down. However, the UK government grant has come down even more. The maximum is now £2,500, whereas it was previously, in practice, £7,000. (See table below.)The government defends its policy, saying that more households will be able to benefit from the lower grant. It also calculates that subsidising households as the Germans do will cost £380m annually.However, our Shadow Trade and Industry Secretary, Susan Kramer commented:“This announcement means fewer people will be able to afford to generate their own electricity.“This will have a knock-on effect on the industries servicing green energy. Even before this announcement, the mishandling of these grants has caused redundancies. This announcement will mean businesses withdrawing from the sector and further redundancies.“The Budget announced an extra £6million for the Low Buildings Carbon Programme. Given that the cuts in grants will no doubt lead to reduced take-up, how exactly will this extra money be spent?”
Technology
Previous maximum grant New maximum grant
Solar Photovoltaics
£15,000 £2,500
Wind Turbines
£5,000 £2,500
Small Hydro
£5,000 £2,500
Solar Thermal Hot Water
£400 £400
Ground Source Heat Pumps
£1,200 £1,200
Automated Wood PelletFed Room Heaters/Stoves
£600 £600
Wood Fuelled Boiler Systems
£1,500 £1,500
Posted by Aberavon & Neath Liberal Democrats

Schoot Solar Thermal Panels

Principle of Solar System Operation

The SCHOTT Evacuated Tube Collector ETC16 efficiently converts solar radiation to heat.
Solar radiation, direct and diffused, is absorbed by the ‘selective coating’ on the absorber surface of the internal glass tube and converted into heat. This heat is carried by the heat transfer liquid and passed to the hot water cylinder during circulation. The vacuum eliminates convection and conduction heat losses as well as protecting the collector from adverse weathering influences.

Solar Energy

The sun is a variable power supply. It is available only during the day and then in varying strengths depending on time of day, cloud cover and season. The greater the intensity of daylight the higher the performance of the solar system will be. On days of low solar radiation the output from the solar collector will reduce providing less energy.

The solar heating system consists of many separate components that play a vital part in ensuring that the system operates to maximum temperature performance efficiency in all types of weather.

The solar circuit is indirect and pressurised. There is no top up tank feeding the system and the sealed circuit does not require topping up.

It is recommended that the system is left switched on at all times

Domestic Hot Water

The hot water cylinder is heated by a heat transfer liquid (Tyfocor GLS) circulating through the solar heating system from the solar panels to a heat exchange coil low inside the hot water cylinder. Having dissipated its energy the heat transfer liquid is pumped back to the solar collector for re-heating. This process continues whilst there is a transfer of heat from the collector to the cylinder. Provided the measured temperature difference DT is higher or equal to the pre-set value and the minimum collector temperature is reached the control unit will operate the pump to maintain the circulation. If these conditions are not maintained the pump will switch off and the control unit will wait for the temperature of the collector to increase before restarting the heat transfer process.

Solar Installations

Talk to me if you have any quiries about solar installations. You can call me on 07092 172269