Friday, November 23, 2007

Home Depot and BP Solar For Homeowners

TreeHugger has an interesting article on a collaboration between BP Solar and Home Depot to provide solar installation to home owners.

The comments section has some good info on the economics, reliability and maintenance of solar panels.

According to the comments -

A typical 1 Kw solar system, that will provide 85% of a homes electricity, is around 22,000 dollars before rebates (maybe 1/2 that or less after rebates). Federal rebates are up to 2000 dollars and some states have rebates plans as well (Florida offers up 20 20,000 dollars for a 2Kw or more home system).

Solar panels have a 25 year warranty and may have a useful life of 40 to 50 years.

The inverter used to convert the DC from the panels, to AC for use by the electrical devices in your home has a 10 year warranty.

Note - The comment that 1 Kw solar system would provide 85% of a homes electricity doesn't sound quite right, unless we are talking about a very energy efficient home. I have a small electric space heater that uses 1.5 Kw and a Microwave that uses 1.2 Kw....so I guess I could either stay warm or eat.

It's not really that simple, because I don't run my microwave 24 hours a day and I rarely use that very inefficient space heater - and when I do it doesn't just stay on but rather cycles off and on to maintain a set temperature.

We have to consider the average energy used during the day/night, when we are home/not home, and seasonal variations to come up with a realistic value for a home's electrical energy use.

I've read the average U.S. home uses about 900 kWh a month. Which works out to be about 30 kWh a day and 1.25 kW per hour...so maybe the 1 kW solar system isn't that far off from what we need after all (at least while the sun is shining).

The nice thing about having the type of solar system that is connected to the grid would be that when we turn on the TV, radio, computer, lights, stove, coffee maker, toaster, microwave and a hair dryer in the morning we can use energy from the grid and when no one is home during the day, and the sun is shining bright, we can feed energy back to the grid.