Photovoltaic Panel Installation Photovoltaics – or PV – represents a method of generating renewable energy which is widely accessible.  If a south-facing roof or un-shaded area of ground is available, then PV can usually be installed to provide clean energy silently and without fuss. Where an electricity supply exists, PV can be “grid-connected”, allowing surplus energy to be sold back or credited to your electricity bill.  An "off-grid" system is used to charge batteries, which then supply "mains" electricity through an inverter. After a site survey which identifies: -    PV system type – “bolt-on” or “integrated” -    The size of the array -    location on the roof, or elsewhere -    access and scaffolding requirements -    location and details of the electrical          equipment required for the grid connection            or battery charging -    planning constraints -    and any building work required… …a quotation for the proposed installation is supplied and a grant application can be made.... The Major Photovoltaic Demonstration Programme of grants for Stream 1 applications (0.5 to 5kWp) closed at the end of March 2006 but a new scheme under the Low Carbon Building programme started at the beginning of May 2006.  Phase 1 of the scheme, for householders, has been suspended until May 2007. Under the LCBP scheme, certain energy efficiency conditions will need to be met, for example for insulation.  Details are available from the EST website. A grant application form and guidance notes can be downloaded from the EST website. The value of the grant is the lower of £2000/kWp or 50% of costs, excluding vat. A "bolt-on" system uses an array of solar panels such as the Sanyo 215.  The array is supported by a framework which is usually fixed to the roof of the building. This Sanyo panel has a rated peak output of 215 watts and owes its high efficiency to “hybrid” construction.  Panels, which measure 800 by 1570mm (about 2ft 8in by 5ft), can be arranged in portrait or landscape fashion to suit the roof space available.  Every five panels of a Sanyo array give just over 1kWp (kilowatt peak) and will produce up to 800 units of electricity each year, depending on orientation and any shading.  Panel arrays are usually the most practical and cost-effective means of installing PV on an existing roof. Integrated systems are designed to be built into the roof to replace tiles or slates and can take the form of.. Integrated modules Shingles Sun-slates Solar Tiles Energy density of Sanyo 215 panels is 170Wp per square metre - requiring six square metres per kilowatt peak, whilst that of Sunslates and Solar Tiles is 110Wp, or 9m2/kWp. the installation procedure... ... in a typical installation, a consumer unit housing main switch, kWh meter and circuit breaker, together with an AC isolator, fits in next to the existing distribution board, on the left in this picture… ... whilst the inverter, plus AC and DC disconnectors, is located in the loft, close to the array.  This unit converts DC from the panels to grid-quality AC.  Inverter output goes through a communication unit which links with a monitor in the house via a radio signal.  The monitor shows the system output at any particular time, the total energy produced and an estimate of CO2 saving. Once the support frame has been installed, the panels are fixed in place.  Because of access problems and a complex roof shape, this installation on Islay made use of designed timber scaffolding. A finished array of 10 panels in Fife, to date producing 850 units per kWp per year...