Solar panels in isolated areas can power emergency telephones or construction site signs.
Solar cells are not only being used in large panels to generate power but also in many small consumer devices to replace batteries. Solar cells generate small amounts of power even when exposed to artificial light, so any device with low power requirements can be powered by solar cells. Since the cells typically last 30 years or more, a well-made device can have a long lifespan. Does this Spark an idea?
The most common application for solar cells in solar electric products is for lighting. Self-sufficient lights for landscape lighting are very popular. They require no wiring and have solar cells mounted on top, a small battery underneath and LED lighting for high efficiency. Similar lighting schemes for camping, sailing and off-grid living are available. Other applications are for solar street lights and solar traffic lights. In each case the unit itself is more expensive than the non-solar alternative but when electricity and cabling costs are included, the solar-powered alternative may make sense.
Many applications require electric power when there is no possibility of supply via electric cables or it is possible only at great expense. Highway rest areas, signs for remote construction sites and sites for emergency telephones are examples. Such applications have had to rely on electricity from batteries that must be replaced or re-charged frequently. It is often more economical to install a solar panel and feed these devices via a re-chargeable battery. When fault sensing and notification circuits are included, service calls for such devices are reduced to a fraction of what they were before.
Small electronic devices often require very little power and are suitable for supplying with electricity from solar cells. For devices that are required to work in the dark, the solar cells charge small batteries. Solar calculators have long been available and will operate even under incandescent light. Solar wireless computer keyboards, solar powered travel clocks and solar powered LED flashlights are also available. The advantage of these devices is the convenience of never having to change or re-charge batteries.
Pumps for irrigation systems require substantial amounts of power and are often located in areas without local electricity service. Since they don’t have to be moved, they can be supplied from large solar panels installed near each pump. If the pump must operate at night, storage batteries will add that capability. Compared with the alternatives of running miles of transmission line or installing a diesel generator, solar power may be attractive from an economic as well as an environmental viewpoint.