Solar Electric systems in Xcel’s Colorado territory- Part One

Solar electric or photovoltaics (PV) offers a complemental power source to Xcel electricity that also is aestetically pleasing – in contrast to the big, gaudy, tilted panels used only to heat water left on roofs from the ’80s.

After homeowners take all other steps to ensure conservation and efficiency in their homes, PV is an economically viable and environmentally responsible option for powering houses. PV gives the whole house – not just a particular device or appliance – power. You don’t have to consider what amps a particular device in the house demands, as PV is simply providing electrons to your service panel, or breaker box. Your breaker box, combined with the service size you get from Xcel (e.g.: 200-amp service), dictates or manages the draw each breaker and associated devices connected to those breakers demands.

Next, PV generates power in the form of Kilo-watt Hours (Kwh), the same thing for which Xcel charges you. When you make a Kwh, you either use it (your house has the right of first refusal) or give it back to Xcel for a credit (you are credited at the same rate you are billed unless you produce more than you use over a year, and then it is a wholesale rate at which you are credited for the net balance).

The limiting factors on the size of a PV system for your house are roof space, production goals (you decide – 50 percent, 75 percent, 100 percent, etc., of the power you use) and budget. Assuming you have the space and the funds, we size the system using a historical 12-month total of Kwh usage. Roof direction, roof pitch and shade all affect system size, as well, but here is a quick synopsis: the average Xcel single-family dwelling in Colorado uses around 8,000kwh in a year. With a roof that faces anywhere from 135 degrees southeast to 200 degrees south-southwest and has at least a standard ranch’s roof pitch of 20 degrees, a 5.5 kilo-watt (5,500-watt) will make you darn near what is referred to as “net-zero” – you make as much power as you use in a year.

How much does PV cost? Many factors can increase or decrease PV prices, but the average, permitted, turn-key price, taking into account the Xcel Solar Rewards Rebate (www.xcelenergy.com/solar/) as well as the federal tax credit THAT WILL EXPIRE IN 2008, is about $14,000 (plus local taxes). That translates to a rate of $0.07/Kwh over the next 25 years of warranted power. That is lower than current rates from Xcel and, considering they rise 3 percent to 7 percent a year, that is a heck of a deal!

Tune in next month for more information, or contact me at John.Shaw@BellaEnergy.com.