They also have low operating costs. They are clean and silent. A photovoltaic system can be constructed to meet any size requirement and can be enlarged or moved to meet changing energy needs. Challenges Photovoltaics work best in regions receiving abundant sunlight. However, even in these areas, batteries or a backup system are necessary to provide electricity at night and during cloudy weather.
Cost is another consideration.
In the U.S., utilities generate electricity from coal, oil and natural gas at very low costs. Markets Developing countries, where half the population is currently without electricity, represent the biggest and fastest growing photovoltaic market. U.S. companies currently export 75 percent of photovoltaic products, mostly to developing countries. Domestically, utilities are the largest potential market, but even at current prices, photovoltaics are less expensive than costly grid extensions and are the most viable form of electric power for many applications. Potential Photovoltaic production has nearly tripled in the last seven years.