While a lot of what we love about solar is intangible, ultimately hard numbers need to work for projects to make sense. This is why we so appreciate hearing from customers with real data about how their system has performed in reality compared to our projections.

Take Peter Guyton, who recently wrote in with a year’s worth of data from his system along with analysis. Peter installed the powerful Powerhouse Dynamics eMonitor to compare his home’s electricity consumption before/after solar, as well as some appliance upgrades.

Peter first discovered that replacing some lights and an older computer netted almost an 11% annual savings on power use. Then, with the solar kicked on, he was able to eliminate his bill completely for some months of the year, and knock it down an average of $136/mo, or $1,631 annually.

Peter also went through a pretty thorough analysis of the investment opportunity presented by solar. Using a fairly conservative rate of 2% electric rate increases measured alongside a modest residual trade-in value for the panels, Peter posited an Internal Rate of Return (IRR) more than double that of treasury bonds:

Thanks so much, Peter, for collecting the data, sorting through it, and letting us share it.