How Does It Work?

There are two main types of solar pv system. Stand-alone systems and grid connected systems. Stand-alone systems are systems which are not connected to the national grid and instead charge up specially installed batteries which then run lighting and other appliances. The second more popular type is grid connected systems these are connected directly to the national grid and feed any surplus electricity back into the national grid. The information below and on the financial incentives page relates only to this type of system.

Solar photovoltaic panels are fixed to your roof or on specially designed stands that can be installed on a flat roof or in your garden. They will ideally be facing due south although they work well when positioned at any orientation between South-East and South West. It is also possible to have a system that is split between East and West if your property has no south facing roof or garden. Maximum power is produced when the panels are at an angle of 30 degrees however, any angle between 10 and 80 degrees will still perform well. In England, changes to permitted rights for domestic micro generation technologies introduced as part of the Energy Act 2008 have lifted the requirements for planning permission for most solar pv installations. Roof mounted and stand-alone systems can now be installed in most dwellings, as long as they respect certain size criteria. However, some local authorities will insist on planning permission being gained prior to installation. Exceptions still also apply for some locations eg : listed buildings, buildings in conservation areas and National Parks.

The panels use energy from the sun to create electricity which you can use to run appliances and lighting in your home. The panels require only daylight, not necessarily direct sunlight, to generate electricity. They will still produce some electricity even when it is cloudy. The greater the intensity of light on the panels the greater the flow of electricity.

Pv systems generate no greenhouse gases. A typical domestic system can save approximately 1.2 tonnes of carbon dioxide emissions per year – adding up to almost 30 tonnes over a system’s lifetime.

Windsor Solar PV Working Demo

The panels create DC (direct current) electricity which is fed into a piece of equipment called an inverter which converts it to AC (alternating current) electricity which is useable by your household appliances. If you are generating more than you are using at any particular time in your house then the excess electricity will be fed back into the national grid via your existing connection.

Prices for pv systems vary, depending upon the size of the system to be installed, type of pv module used and the nature of the actual building on which the pv is to be mounted. The size of the system is dictated by the amount of electricity required, the available roof space and the budget.

Grid connected systems require very little maintenance, generally limited to ensuring that the panels are kept relatively clean and that shade from trees has not become a problem (any shading of the panels reduces the performance of the system). The wiring and other electrical components of the system should however be checked regularly by a qualified technician.