Saturday, June 23, 2012

Harvesting The Power of the Sun

Our home, Herons' House,  seeks to partner with nature and use the resources provided by nature. One of the greatest gifts of nature is sunshine. We use this gift both passively for heating and actively to generate electricity. As a solar energy generator, it's great to see technology advance to the point where we can power our home and automobiles with sunshine.

SDG&E now allows you to view your energy use online with the My Energy tab. It's a great tool to see how much electricity you use and when you are using the electricity.

For our home (not small) and our electric BMW ActiveE (18,000 miles a year) we are averaging below zero for the entire summer, -11kwhs per day.  

The above chart shows different times of the day and different energy rates.  The yellow line is the average.

The on peak rate (dark blue) is $0.30 per KWH. The off peak rate is $0.18 per KWH, the super off peak rate is $0.14 per KWH. So every KWH of peak generation when we are sending extra energy to the grid, is equal to 2KWH of usage during off peak or super off peak which is when we charge the BMW ActiveE.  It's essentially a 2 for 1 sale. In a gasoline world that would be like buying gas at $4.00 a gallon during the day and then $2.00 a gallon after 6pm and before 6am. When would you buy your gas?

Our last years annual utility bill called a "True Up" was $35.  That's less than $3 a month to live in a 4500 sq ft home and drive a BMW ActiveE 18,000 miles a year. We are still trying to work off a $232 credit from the prior year. It may take us a few years :)

For the rest of our lives we will essentially live and drive on the free power of the sun.

Here is a very nice letter from SDG&E. How will we use those extra KWH's? Hey, we could get two BMW electric cars! :)  Perhaps a BMW i3 and a BMW i8.

System size 7.5 KW --- Generation 11,750 KWH per year --- Home and Car usage 11,250 KWH per year --- System install 5.5 years ago --- Cost $32,000 --- Savings to date $35,000

The power of the sun is unbelievable and endless. The future is here.        

Spouse of an ActiveE driver, 7,700 miles
47,000 total miles powered by sunshine.

1 comment:

  1. Congrats Peder! I can see you smiling that great solar-charged smile right now! Keep up the fantastic work on behalf of solar + EVs!

    BTW, did you see the feature story I just did on David Shira for SolarChargedDriving.Com --

    In his positive energy for solar, and his positive energy for life, David reminds me quite a lot of you :-)