When Photons from the sun hit the panels Electrons go into motion creating direct current.

This is transformed into alternating current using a Solar Inverter.

In the 1970s improvements in efficiency began and they gained in popularity throughout the 1980s.

Since then the production of PV Panels is growing at an annual rate of 25%.

The picture to the right is a Solar Attic Fan.

Pictured here is an inverter tied into the meter. When the utility company agrees to buy back (they actually give you credit for using less power than you create) power it is known as Net Metering.

The pros of Solar PV are that it is renewable. It does not pollute so it is environmentally friendly, and it offers free Solar Power after the initial cost.

These systems have no moving parts. They can be expanded.When they are properly installed PV Systems require very little maintenance and have long service lifetimes.The cost per kilowatt produced is also dropping.

Simply put you can buy a 215 watt panel today for what a 195 watt panel cost last year.There are in place Federal Tax Credits and possible state incentives.

The cons of PV are the high cost of panels and equipment. In North America, for optimum efficiency panels need to face south.

Another factor is space, either on a roof (with a good southern exposure) or a pole mounted panel array. These factors could add to your cost. A pole mounted system can add to the cost both in labor and materials.

An off-grid system will cost more because of batteries needed for storage as well as a charge controller to insure battery safety.

Thermal is arguably the most efficient use of Solar Power. This could range from home hot water to swimming pools or even radiant heat.

In commercial applications it can be used to create steam to power generators.

The pros of Solar Hot Water out weigh the cons. A properly installed residential system can save you 50-90% on the cost of heating your home water.

An average payback on these systems is from 5-7 years. At 7 years that is a 10.28 return on investment.

The same Federal Tax Credits and possible state credits or rebates apply here as well.

The pros of the Solar Pool Heating System are these.

It will add time to both ends of your swim season. Compared to the cost of a gas heater or heat pump the payback on this system is 3-5 years.

At 5 years this is a 12.8% ROI. This is also a very efficient use for Solar Power

The cons for hot water and pool heating are that they will not produce on cloudy days.

You will need a backup electric element in the storage tank for residential hot water systems in most cases. A Solar Pool Heating system may require a Solar Blanket to help stop heat loss at night.

Negative aesthetics. Tax credits do not apply to Solar Pool Heating.

Passive Solar Energy is the use of sunlight for heating using no mechanical systems.

One example would be a south facing wall using plenty of glass or windows. The roof overhang would be longer than normal to allow winter sun in while shading the hot summer sun.

Another would be locating windows low on one side of the house (exposed to the most natural wind) and using a Skylight that can be opened to create air flow.

Since hot air rises it will create a natural breeze effect.

Solar Tube Skylights can be used to divert daylight to any room in the house.

The cons for Passive Solar are the initial building costs can increase. There is need for more planning which could also add to cost. To much passive gain can be difficult to control.

The pros of Passive Solar are the reduced energy costs (as much as 50% for heating and cooling).It's renewable, non polluting, and reduces green house gases.

More Solar

Solar Hot Water

Concentrating Solar

Hybrid Energy

Electric Cars

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