A1: Modern solar cells with practical efficiency were invented in the early 1950s, and have been used to power satellites since 1959. They became popular for terrestrial applications in the mid-1970s, mostly for remote telecommunications, navigational aids and other rugged, remote industrial uses including microwave, TV, radio and cellular repeater stations. They have been powering urban applications such as roadside emergency telephones and traffic sign boards since the mid-1980s. With prices dropping steadily, they are now becoming affordable for urban homes and businesses.

Q3. What does photovoltaic (PV) mean?

A3: The direct conversion of light into electricity. Photovoltaic cells convert sunlight directly into electricity. When sunlight strikes a PV cell, electrons are dislodged, creating an electrical current. Photovoltaic cells power many of the small calculators and wrist watches in use every day. More complex systems provide electricity to pump water, power communications equipment light homes, and run appliances. Beyond the utility power line, PV is often the lowest-cost means to provide electricity, and almost always simplest and cleanest to operate. 

The cost of PV has fallen by 90 percent since the early 1970s. Photovoltaics are producing electricity for critical loads from the polar ice caps to the tropics to satellites in outer space. There is a strong market today in developing countries to provide rural electrification with solar panels, which replace kerosene lamps, batteries, and wood fires at a far lower cost than the central station power plants. 

Photovoltaics are also making inroads as supplementary power for utility customers already served by the grid. Currently costly compared to most conventional choices for grid power, Photovoltaics is still a very small part of the energy make-up of any country. However, more and more individuals, companies, and communities choose PV for reasons other than cost: because of a desire to develop a clean, sustainable energy source, interest in a clean back-up power source, a need for placing power generation right at the source with no fuel, noise or moving parts; and an attraction to a power technology that can be built right into building roofs, facades, canopies and windows

Q4. What is a PV cell?

A4: The smallest semiconductor element that converts light into electrical energy (DC voltage and current).  

Q5. What is a PV array?

A5: An interconnected system of PV modules that function as a single electricity-producing unit. The modules are assembled as a discrete structure, with common support or mounting. In smaller systems, an array can consist of a single module.  

Q6. What is a solar cell and a solar module?

A6: A solar cell, also called a photovoltaic (PV) cell, is the smallest element that converts light into electrical energy. Each cell is made of silicon like a computer chip. The silicon is treated so that it generates a flow of electricity when light shines on it. Solar modules are series of solar cells wired together.  

Q7. What is a PV system?

A7: A PV system is a complete set of components for converting sunlight into electricity by the photovoltaic process, including the array and the balance of system components.  

Q8. What is PV conversion efficiency?

A8: The ratio of the electric power produced by a PV device to the power of the sunlight shining on the device.

Q9. These panels are made of amorphous type solar cells. What is the difference between amorphous cells and polycrystalline cells?

A9: Amorphous solar panels contain no cells per say but are created rather through a deposition process which actually forms the silicon material directly on the glass substrate. To understand this a bit clearer, think of it as spraying the silicon onto the glass in very thin layers. This film which gives amorphous panels the "thin-film" nick name, is laser patterned which interconnects instead of physical connecting tabs which eliminates a mechanical connection that can break down and fail. The amount of silicon used in this process produces a film, which is often up to 100 times thinner than that of a polycrystalline cell. Furthermore, amorphous type solar cells are better at generating electricity in all lighting conditions.  

Q10. Are solar electric systems safe?

A10: Yes. Solar cells are mostly silicon, the primary component of sand. There is no exhaust and no toxic materials to leak out of the system. The electricity coming through the inverter is just like the electricity coming from household wall sockets; you should use the same care you would with utility power. All components are approved for utility interconnection and are installed according to standard construction practices.  

Q11. Are solar power systems good for the environment?

A11: Yes! Energy created through our solar electric system produces no pollutants. Our smallest system typically cuts greenhouse gas emissions as effectively as 50 trees.  

Q12. How well do solar panel withstand, and work in, inclement weather?

A12: In cloudy weather, solar modules work, although they produce less electricity than on a sunny day. Under a light overcast, the modules might produce about half as much as under full sun, ranging down to as little as five to ten percent under a dark overcast day. If the modules become covered with snow, they stop producing power, but snow generally melts quickly when the sun strikes the modules; if you brush the snow off, they resume operation immediately. Our modules can withstand one inch (2.5 cm) hailstones at 50 mph (80.5 kph).  

Q13. Can my panel be left outdoors without a protective covering?

A13: Yes. The Solar Module has been weatherproofed and can be mounted outdoors without any additional protection