Most PV manufacturers are confident to offer 20-25 years' written guarantee on their products. The semiconductor technology in wafer cells suffers minimal wear and tear, much like long-lasting transistor radios. Some manufacturers offer further guarantees, such as immediate replacement or repair of modules which lose over 10% power output in the first 10 years and 20% up to 25 years.

This Limited Liability Warranty is listed in the company's standard warranty but there may be other details to consider. Cell technology and workmanship are generally of high quality so purchasing those that offer the best warranty is smart. Although the cells are fragile, they are protected by a specially-designed, sealed, tempered-glass surface and backed with strong plastic.

The cell is then enclosed in a non-corrosive aluminum casing as a finished product. Packed together as an array, they can be roof-mounted or fixed on a tracking rack. It is easy to maintain PV modules. Ice and snow can build up on the glass and should be brushed off with a wet sponge. Do not try to break the ice. The sun will do the rest by melting the snow and ice on the panel, even at temperatures lower than -4°F (-20°C).

Use the following checklist to ensure that your PV module works well. Consider your installation location carefully then:

• Calculate how much electricity you require.
• Make sure the sun has direct access to your PV panels.
• Decide on mounting mode (track or rack).
• Get rid of shade.
• Factor in winter ice and snow coverage.
• Do not overheat modules during the hot season.
• Determine preferred system voltage.
• Put arrays as close to batteries as possible.