At a time when energy prices and concerns over global warming are increasing, this Saturday (October 7 th) offers a great opportunity to learn about the benefits of solar energy. The 11 th annual Denver/Lakewood/Golden Tour of Solar and Green Built Homes (and October 8 th in Boulder) provides the opportunity to see what people are doing to make their homes and building more energy efficient.

Led by the Colorado Renewable Energy Society, the day-long tour provides hands-on information for the homeowner who is considering installing a solar electric, solar water or energy efficient system and take advantage of renewable energy financial incentives. Many of the 14 homes and two businesses on the Tour go beyond your average 'energy improvements' with examples of green building materials, according to CRES Director Shelia Townsend. Cost of the Tour is $20 per carload, or $35 per person for the guided bus tour. Call 303-443-4308 for further information or www.cres-energy.org.

The cost of solar electric systems in Colorado has dropped substantially with the introduction of the Xcel Solar Rewards Program earlier this year. Xcel offers a $4.50 per watt rebate (equal to half the cost) for a solar electric or photovoltaic (PV) system. An additional $2,000 federal residential income tax credit is also available. Together, these incentives cover more than 60% of the total cost of a PV system.

A PV system converts sunlight into electricity by producing direct current (DC) when the sun's rays hit the PV panels. This DC current is converted into alternating current (AC) by an inverter, which is used to run your refrigerator, lights, dishwasher, computer and other appliances. The word photovoltaic was first used in about 1890 and derives from the Greek word phos, which means light, and volt, a measurement unit named for Alessandro Volta (1745-1827), pioneer in the study of electricity. Photovoltaic cells (PV) are a semiconductor-based technology developed in the 1950s for space satellite power. PV technology uses no fossil fuels, has no moving parts and produces no pollution.

The cost (and size) of a residential PV system in Colorado depends on several factors, including: the amount of fossil fuel-based electricity you want to offset; available roof space and your budget.

A 4,000-watt or 4 kW residential PV system, after rebates and tax credits costs about $16,000. This system will produce almost 500-kilowatt hours of clean energy a month, which represents 70% of the average home's electrical needs. Plan on 100 square feet per kilowatt or 400 sq. ft for our 4 kW system. With great rebates from Xcel, increasing electric costs and concern over pollution, now is the time to go solar.

SolSource Inc., one of Colorado's leading solar energy design and installation firms, will be showcasing several of its 'high performance clean energy' homes, including the John Avenson and Steve Szabo residences, as part of the Tour. SolSource Inc., located at 5919 N. Broadway in Denver offers solar electric and solar hot water systems along with energy efficiency products and environmentally sound interior finishes (plaster and clays) for homes, schools and businesses. The company has installed over fifty residential systems since 2004 and was recently asked by Xcel to service all of it's twenty-nine school based solar electric systems.