Nick Mills has recently moved from Wales to Stroud, and has installed both PV and solar hot water panels on the roof of his stone cottage in Slad Road.
Nick has worked for a renewable energy company for many years, and was keen to install the technologies at his house, despite the long financial payback time for PV panels. He installed his 21/2 kWp system in April 2007, and received the maximum grant available at the time from the DTI through the Low Carbon Buildings Grant of £3,000 per kWp installed. The grant covered approximately 50% of the total cost of his PV system (around £13,000)
Photovoltaic panels provide a solar electric system converting sunlight into electricity. They involve no moving parts and create no noise or emissions. At optimum conditions, a south facing roof in the UK will generate approximately 750kWh of electricity per kWp installed, with a higher yield in the South of the country. Average electricity consumption for a UK household is 3300 kWh per year, so a 2kWp PV system should provide about 50% of electricity needs. Remember, the first step should always be to reduce electricity consumption before investing in PV panels.
A kWh of electricity produces 0.568kg of CO2 in it's manufacture, so Nick's system will offset around 1,136kg of CO2 per year. About 7.5m2 if roof space is required for each kWp of a PV system, and it is important that all the panels are unobstructed if the whole system is to function effectively. An inverter, approximately 0.6m2 in size is the interface between the PV generator panels and the grid, and can be placed in the loft or another suitable place. It converts the current from DC (direct current) to AC (alternating current), and this electricity can be sold to the grid if not consumed on site.
Permission to connect to the grid must be obtained from a Local Distribution Network Officer before the PV system is turned on. A bi-directional meter is used to record the amount of energy imported from and exported to the grid. Prices for the meter vary according to the power company used, and it is best to do your research before you install your PV panels. Generally the cost is around £50-60. Unfortunately, the price paid for electricity exported to the grid from micro-generation is often a third of the price you pay to import it, so it can be worth shopping around! Remember that a good deal on imported electricity may offset an attractive offer for exported electricity.
With his 21/2 kW system, Nick Mills hopes to produce about 2,000kWh of electricity per year. "I have been monitoring the PV panels carefully", says Nick Mills, "and they can generate up to 18kW of electricity on a good April day, about 2kW on a grey, rainy day. Since we installed the panels we have had three sunny weeks and have generated roughly 200kWh of electricity, a great start!"
Nick does not foresee high maintenance costs for his PV system. "The panels should self-clean on a normal roof slope, and, as with all electrical equipment, there should be a ten yearly periodic test." he says. "With no moving parts to deal with, maintenance costs should be minimal. We anticipate the biggest problem to be bird droppings obscuring the panels!"
There is money available for domestic renewable technologies through the government's Low Carbon Buildings Grant. An approved installer will need to be used. As the grant is reviewed regularly, it is best to check the website at the time of application to find out how much is available for PV.
Stroud District Council has a grant of £500, available through their WISE Homes Grant, to encourage local householders to install renewable technologies in their home. This money is available in addition to any money received through the Low Carbon Buildings Grant.
Do check with the Energy Savings Trust and the Centre for Alternative Technology for any further grant possibilities.
For information on local planning issues at the District Council contact Planning on 01453 754442 or email planning@stroud.gov.uk
