Solar power may be the most exciting alternative source of energy. After all, the sun is the most reliable energy source available to our planet, and using solar energy has very little impact upon our environment.

However, the cost of installing equipment to turn the sun's rays into electricity or hot water tends to be very high. In addition, the sun presents a problem for solar energy users: it disappears for half the day, and often hides behind clouds. Because of those factors, it typically takes decades for the average homeowner or business owner to recover the cost of a solar energy installation.

Turning sunlight into electricity involves the use of photovoltaic cells. Because photovoltaic cells cannot produce electricity when the sun isn't shining, the home or business owner must install a large battery backup system, or rely on a power supplier when the sun isn't bright enough.

Solar equipment salespeople may mention that power companies are required to purchase any power you don't need. That's true, but you'll be responsible for the cost of the extensive engineering required to delivery power safely to your power supplier's lines. Plus, any power you sell will be at a lower wholesale rate, not the higher retail rate you pay for power you use.

Solar power can also be used to generate hot water. Because water heating is the second-biggest user of energy in most homes and businesses, a solar system can reduce electric or gas bills. However, once you factor in the cost of installing a system, it can take many years for a solar water heating system to pay for itself.