As electric bills go through the roof, the price of solar electric systems are starting to look more affordable these days.

Solar water heating for home use and as means of heating pool water has been an affordable and popular technology for many years. Now, harnessing the sunís energy to power the home is growing increasingly popular, especially as energy prices rise and solar systems become more advanced and reliable.

Photovoltaic (PV) systems convert sunlight directly to electricity. They work any time the sun is shining, and though they generate maximum juice when the sunlight is striking the PV modules directly, they even work when itís cloudy outside, as evidenced by the rising number of people in mostly cloudy Portland who have gone solar.

Recent innovations have also improved the look of rooftop solar systems. Solar tiles are available that look like ordinary roofing, and which blend in with most popular roof styles.

A typical energy roof uses about 300 square feet of surface. In a sunny climate like the Rogue Valley, it produces many thousands of kilowatts of clean energy per year. Any excess power you have can be fed back into the utility company grid for a credit on your bill.

Before you decide to buy a PV system, there are some things to consider:

PV produces power intermittently because it works only when the sun is up. This is not a problem for PV systems connected to the utility grid, because any additional electricity you need is delivered by the power company. In the case of non-grid, or stand-alone, PV systems, batteries can be purchased to store energy for later use. Batteries are also an option for storing excess power when connected to the grid.

If you live near existing power lines, PV-generated electricity is usually more expensive than conventional utility-supplied electricity.

Although PV now costs less than one percent of what it did in the 1970s, the amortized price over the life of the system can still be higher than what most people pay for electricity from their utilities.

State and federal tax incentives and solar rebate programs from the Energy Trust of Oregon help make PV more affordable. The Energy Trust offers incentives of up to $10,000 for residential systems.

Combined with federal and state tax breaks, the incentives can cover 50 percent of the cost.

You may want to finance your PV system, which allows you to spread the cost over many years. Many PV installation companies have teamed up with lending institutions that offer creative financing.

The price for a PV system depends on a number of factors, including whether your home is under construction and whether PV is integrated into the roof or mounted on the ground. The price also depends on the PV system rating, manufacturer, retailer and installer.

The size of your system may be the most significant factor in any measurement of costs versus benefits. For example, a 2-kilowatt system that meets nearly all the needs of a very energy-efficient home could cost $16,000 to $20,000 installed, or $8 to $10 per watt.

At the high end, a 5-kilowatt system that completely meets the energy needs of many conventional homes can cost $30,000 to $40,000 installed, or $6 to $8 per watt. These prices are rough estimates; your costs depend on your systemís configuration, your equipment options, incentives and other factors.

How do you identify solar electric system providers? Here are several suggestions:

Contact the Solar Energy Industries Association (SEIA) at (202) 628-7745 for a list of solar service providers. SEIA is the national trade association of solar energy manufacturers, dealers, distributors, contractors, installers, architects, consultants and marketers.
Contact your utility company to see which vendors it might recommend.

Contact the Energy Trust of Oregon (energytrust.org or (866) 368-7878), which maintains a list of solar contractors in Oregon that is broken down by regions of the state. The list currently includes 17 contractors who install solar systems in the Rogue Valley.

Getting more than one bid for the installation of your PV system is a good idea. However, make sure all bids are apples for apples. For example, a bid for a system mounted on the ground is usually very different from a bid for a rooftop system. Similarly, some PV modules generate more electricity per square foot than others. Bids should clearly state the maximum generating capacity of the system (measured in watts or kilowatts). If possible, have the bids specify the system capacity in ďAC wattsĒ under a standard set of test conditions, or specify the output of the system at the inverter.

Also request an estimate of the amount of energy that the system will produce on an annual basis (measured in kilowatt-hours).
Because the amount of energy depends on the amount of sunlight, which varies by location, season, and year to year, itís unlikely the contractor will quote a specific figure, but rather a range.

Bids also should include the total cost of getting the PV system up and running, including hardware, installation, connection to the grid, permits, sales tax and warranty.

óStory written from wire and staff reports.