If you are using solar energy, you need to know the total cost. Next to the purchase price, until sunset is the second largest expense.

"But how much? "Is a common question in solar energy. This is a difficult question to answer because the amount depends on several factors: where you is in the world, how much sun you get, and the amount of energy is not used.

When you live in the world determines the amount of sun you get each day. Since solar energy is dependent on sunlight, you must have a certain amount in order to generate enough power. How much sun you get is also related to where the panels are hung on a structure. Angle, direction and shade are the factors to consider. To work best, solar panels facing south, at angles ranging from 15 to 40 degrees. How much energy is used can be determined by the following process, which was developed at the National Renewable Energy (NREL).

Consumers need their electric bill to find out the cost of going 100% solar. The first step is to divide the total number of kilowatt-hours (kW) by 30 to obtain average daily use (many bills that already have this number broken out, so in that case, you can skip the first step.) Once you determine average KWH consumption per day, that number is divided by the average number of hours in full sun per day. That ratio is then multiply by 1.15 to give a comfortable margin. An example of this formula looks like this: 500 kWh / 30 = 16.67 kWh per day. 16.67 KWH / 7 = 2.38. 2.38 X 1.15 = 2.74 KW or 2740 watts necessary solar panels.

According to NREL, the average cost of installing a solar system is around $ 7.00 or $ 9.00 per watt if you have installed by a licensed professional. Since some of the rebates require a licensed contractor, the latter is recommended. This average includes the cost of the panels solar, inverters, brackets, cables and hardware, but does not include the price of inspection or costs related to obtaining the grill with your local company electricity. Using the previous example, then the system would cost about $ 24,660 to install, plus another couple of thousand dollars for inspections and fees.

While this may seem like a great investment, there are federal, state and local incentives to go solar. There is an annual tax break Federal at about $ 2000 for solar users. Most states part of the rebate installation and purchasing costs. The local energy companies will buy your excess energy, reducing overall bill for when you need to be "in the grid." And consumers can still get some these incentives, even if they only go partially solar to start.

Rick Chapo is with SolarCompanies.com – learn more about solar panels.

Solar Energy Basics for Your Home