Solar PV Systems

Photovoltaics (PV) is the conversion of light into electricity.

Photovoltaic Modules

PV modules consist of a number of semiconductor PV cells connected together to provide a 'standard' voltage of 12V DC. Current and hence power output varies with light level up to peak output in full bright sun. Although the output could be used to directly power DC appliances, such as pumps, due to the variability of sunlight PV modules are usually connected to charge batteries for DC stand alone systems or connected to the mains grid through an inverter for AC grid connected systems.

These maintenance free panels have no moving parts, make no noise, cause no pollution, and will produce useful power even under a grey overcast sky.

A solar electric system has the advantage of being quick and easy to install with a minimal requirement for site preparation. Also their modular design allows the easy expansion of a smaller system if needs change.

Simple and reliable, they are ideal for:

Stand Alone Applications:

Rural and remote power needs
Maintaining the charge in infrequently used batteries
Powering lighting, pumps & garden fountains
Charging batteries on boats and caravans
Providing reliable electricity supplies for properties off the grid

Grid Connected Applications:

Domestic grid connected systems
Megawatt utility powerwatt generation
Integrated into building facades
Mounted on domestic roofs
Used as the roofing material itself

Photovoltaic systems are the only form of renewable energy that can be widely deployed in towns and cities. Where appropriate hybrid’ systems combining PV with wind turbines or other forms of power generation can give a balanced supply all the year round. (see page on system sizing)

Over it's estimated life, a PV module in a sunny climate can produce at least 20 times the electricity used in it's production.

Choosing PV Modules

Photovoltaic modules vary and a wide range are available for every application. They must be chosen carefully, the following factors are important in making that choice:

Warranty - Normally stated as a guarantee to produce no less than a percentage of power rating for a given period. Only of any value if the manufacturer of the module is likely to still be in business for that time period.

Quality - How well the modules are made. This affects how well they will work and will last. Illustrated by features such as strength of frame and efficiency.

Power Tolerance - Normally stated as a plus and minus percentage of power rating.This is important when comparing prices - eg. a 170 Wp module with +/- 10% power tolerance may only produce 153 Wp so may not be such good value as a more expensive module with a tighter power tolerance.

Energy Production - Normally stated in terms of kWh/kWp per annum ie. Energy that should be expected per year from a well sited 1kWp PV system. This depends upon efficiency of the module, accuracy of it’s power rating and responsiveness to varying light levels. Different modules with the same nameplate rating will produce differing amounts of energy and will age differently. All the modules in this catalogue have been chosen to be amongst the best available considering the above criteria.