Buying PV Solar Panels?

Are PV panels viable?

PV modules or Solar Panels are undoubtedly the sustainable energy solution for homes that provides the lowest operating costs. With the SEI/CER Micro generation program now ready for implementation PV panel installation will be hard too beat in the right locality.

PV cells have been around for centuries but even now research is on for newer technologies. This is because the solar energy conversion efficiency of the commercially available PV modules is never more than 13 -15% in actual usage. The beauty of it though is every watt thus generated is free and renewable. About 80% of all the PV modules manufactured for terrestrial applications are still the crystalline first generation type.

Are all Solar Panels equal?

Certainly not! The same way there are many different materials used, there are different performance details which differ. Quality standards is another matter altogether. Unless you are at least conversant with basic electricity and distribution of it in homes you would do better to leave everything to a professional. But for those who are technically minded these are some facts to evaluate when you buy PV panels.

• Quality Standards

As all other equipment imported in to the EU market PV solar panels also should conform to CE, ISI, BS or EN pertaining to the item. ISO 9000 series quality management and, ISO 14000 series environmental management system etc are the other relevant standards pertaining to the manufacturing process and the facility. You will have to ensure the manufacturer's standards certificates cover the model and the year of manufacture of the unit you intend to purchase. (These validities have to be periodically renewed).

• Performance data - what to look for

Specification : Solar Cell- type, size and the profile

No. of cells and how they are connected (series /parallel)

Typical application- Voltage DC

Maximum Voltage- in V DC

Module Size- length X width X height ( mm )

Weight of Module ( kg )

Thickness of Front Glass- ( mm ) and whether toughened.

Operating Temperature range-( 0 C )

Nominal Operating Cell Temperature and tolerance - ( 0 C )

Rated Safe Hail Diameter measured at 80 kmph ( mm )

Continuous safe wind pressure- (kmph)

Connection type cable size /special connector needed or not

Electrical Specification : Rated Power ( watts )

Tolerance ( % )

Rated current- ( A )

Rated Voltage ( V )

Short circuit current- ( A )

Open circuit voltage- ( V )

Voltage Temperature coefficient ( V/ 0 C )

Current Temperature coefficient-( %/ 0 C )

Power Temperature Coefficient ( %/ 0 C )

Characteristic curve-Ampere vs Voltage

( irradiance@1000w/m 2 )

Characteristic curve-Ampere vs Watts

( irradiance@1000w/m 2 )

Conversion efficiency ( % )

Constructional features : Type of supporting frame

Material of the frame

Mounting method and the material of brackets

Water sealing method

Warranty: Applicable warranty on critical components like Solar cells and the Module (complete), Frame and mounts (if supplied by the Module supplier), Cables and connectors, Water Sealing Method etc.

In an evaluation the above performance and characteristic details will enable you to do an apple to apple comparison of the multitude of types and brands of solar modules currently available in the market. As said earlier if this is too techie it is prudent to get the assistance of a solar panel specialist who (if every other avenue fails) are always available with suppliers and manufacturers agents. This technical evaluation must naturally precede any price evaluation to safeguard your valuable investment.