Tuesday, June 17, 2008

Charting Seasonal Output


Now that many of us who got solar in 2007 have completed our first solar year, some interesting results are available for those of us who have charted our usage. The graph above shows the average value (in dollars) of my solar system's daily output over the 13 month period from 5/15/07 to 6/15/08. (I'm on the E-7 rate plan, which is no longer available to new solar households).
Because the E-7 peak rate is $0.28 from May 1-Oct. 31 and only $0.10 from Nov. 1 to Apr. 30, my solar system generates very little value for six months of the year. (It faces WNW, which exaggerates this effect compared to a South-facing system.) So, if I ever need to take my solar system offline to re-roof, I whould do it in early November when the weather here is usually quite nice (but the value of my solar output is paltry.)

1 comment:

Unknown said...

Dear Bruce,

Your chart looks interesting. I just had a system installed and it is waiting for the net-metering hookup.
If you can retrieve and plot your KWh numbers --especially your Peak and partial peak periods; then one can perform a better analysis about the PV's $ impact.

Please keep up your reporting.
Steve
P.S. get a quick checkup on your PV at www.pvperformance.com