The association has also found that the installation and system costs are coming down in price and it is estimated that the average cost decline from 1998 through to 2009 shows a reduction in cost of $0.30 per watt.

Ohio is the forerunner for solar energy in the United States due to the extreme weather conditions and it has perhaps the most ambitious solar energy set up of any other state. By 2025, 25% of Ohio's electricity must be produced by solar energy.

There are various incentives available for households and businesses but this varies from state to state but using Arizona as an example the incentives are listed below.

All residential installations of solar systems will be allowed a personal tax credit incentive of up to 25%. There is a cap on this credit of $1000 and this figure applies regardless of the number of units that are installed.

Property Tax Exemption

The Solar Energy Property Tax Exemption in Arizona reimburses residents 100% of the increased value of their property after the installation of a solar power system providing the power used is without the assistance of conventional power sources

Utility Loan Program

The residents of Arizona are able to apply to the GEOSmart Financing programme when installing systems that generate solar energy. This scheme permits residents to receive a maximum of $50,000 at an interest rate of between 8% and 13%.

Many other states as well as Arizona offer a Renewable Energy Credit Purchase Programme. This works by offering residents the option of selling back any excess generated energy back to the grid and receiving a credit for doing so.

There is extensive information available regarding all aspects of solar energy from the US governments website http://www.eere.energy.gov which offers advice to both personal and business users.

The development of the solar industry is centred around the Solar Energy Technologies Program which focuses on the most innovative and cost effective solar energy technologies which will benefit both the US and the rest of the world.