Happy Earth Day, living and driving on sunshine.
You can live in a home and drive a car powered by sunshine. In our case we live in 3500 sq ft home and drive a BMW Mini-E 16,000 miles a year. Both powered by sunshine via a 7.5 kw Sunpower Solar P.V. system:)
Solar PV owners have a net metering agreement with SDG&E that allows you to pay once a year for the energy for your home. For the 2010 year we estimate our total energy use will be between 0 and $100.
In the early part of the Year, January through March, we use more energy than we produce and we have a bill. In the mid part of the year from mid March to October we generate more energy than we use and we have a credit every month for 6 months. At the end of the year we again use more than we generate and we have a bill. At the end of the year we are essentially energy neutral or net zero.
In actuality the home produces far more energy than it consumes because it also supplying 3500kwh, the equivalent of $1850 of gasoline annually to power the Mini-E.
This is our most current bill and you can see that we started at 70304 and ended at 70297. a -5 KWH usage for the month. The normal SDG&E bill does not give you credit for generation so the top lines of -270 and -75 show 0 when in reality you get paid for that at a higher rate than super off peak..
This is the net metering bill that you keep track of the year with. You can see in January and February we had a bill of $102.42 and $65.49 and then in March we have a credit of $-11.72 and a total KWH of -5
From now until October we will have a credit. In May the summer rate structure begins which is better for us and we will have credits around $40 to $60 per month. The below chart is an approximation of how our year looks.
The Solar PV system is now two years old with the new gas station addition 8 months old. We have generated almost 20 megawatts of energy with a value of $6,600. in electricity plus $1850 in gasoline for a total savings of $8450. This represents around 35% of the total system cost ($26,000) and puts our break even point at around 6 years, less if electricity rates or gas rates spike.
Remember, this is 6 years of the same payments you are already making to SDG&E and you local gas station, it's not a new payment.
How can anyone afford not to do solar or drive an electric car!
Cheers
Peder