On browsing through Photovoltaic solar panel web sites of manufacturers you would come across a variety of specifications, classifications, terminology, and capacities. An average non-technical person would easily get confused instead of getting the information he is looking for.

Here are some interesting facts to remember when browsing through their e-catalogues:

• The PV panels are rated according to the peak power they produce in watts DC. All manufacturers anywhere in the world would indicate this.

• The PV panel s have an efficacy depending on the physical characteristics of the materials used. For example the commercially produced Mono crystalline Silicon PV panels could be as efficient as up to 18%.The Thin Film PV panels on the other hand would be only about 8-10% efficient. The efficiency we refer to here really is the conversion efficiency of solar energy incident on the PV panel to DC electricity.

• The efficacy also will depend on the purity of material, design of panel, manufacturing technology and process and so many other factors as well.

• The recorded maximum conversion efficiencies (Solar energy to electrical energy) of various types of PV panels (as compiled by NREL-USA) are as follows:

• Mono Crystalline Silicon PV Panels – Mono crystalline refers to the type of physical structure of the silicon PV material (Efficiency=25.0 % max.)*

• Poly crystalline Silicon PV Panels – Poly crystalline refers to the type of physical structure of the silicon PV material and the efficacy is less than that of the mono crystalline product but cheaper in price. (Efficiency =20.4)*

• CIGS Thin Film PV Panels – CIGS refers to the Copper Indium Gallium di Sulphide semi conductor material and exhibit a wide spectrum of advantages over the traditional Crystalline Silicon material’s physical properties. Thin Films are naturally flexible and are manufactured in rolls. This makes it (just like all thin film PV material) easy and cheaper to ship when the kW densities are compared. It is a newer material and technology. (Efficiency=20%)*

• CdTe PV Thin Film Panels – The semiconductor material is Cadmium Teluride and the physical nature is a thin film in contrast to the conventional panels of up to 50 mm thickness. It is therefore flexible in practical application. Efficacy is less than that of the Silicon PV Modules. (Efficiency = 16.7% max.)*

• Amorphous Silicon Thin film PV Panels – It’s practically a wonder PV product in that the Amorphous Silicon material is deposited direct on glass or even plastic substrates. The semiconductor material is deposited on long plastic rolls, or any other flexible backing like laminated plastic, shingles, roofing tiles and such other material. The colour is uniformly distributed in this PV material. Therefore are easily blended aesthetically in to the architectural designs where they are incorporated for sustainable energy production. (efficiency=12.5% max)*

*All efficiency figures refer to research level observations. The production model capacities and performance widely vary. Readings reproduced here are indicative and for comparison only.

The world over you would find some reliable pioneering companies manufacturing high quality PV Panels. Apart from the specialized manufacturers in UK, USA, Germany, Japan etc. large corporations like Sharp, Hitachi etc. too are engaged in research and development and also mass production.

China has now emerged as the world's 3rd largest user and the largest manufacturer of Photo Voltaic Panels. The use of PV panels in large numbers within the country in increasing numbers and the state patronage has developed the industry itself and today one finds hundreds of manufacturers there. The end result has been the dropping down of the price of PV panels considerably in the world market. If you are looking for PV panels, made in China, one word of caution! All Chinese PV products are not of high quality though there are a few. In fact many are not! Look for the appropriate (and valid) certifications for compliance with British, Irish or EU quality standards.