Kelly and I had been wondering how much money we are saving with our solar PV system, so tonight I worked a little spreadsheet magic. Bottom line? Our electric bills so far have been half what they were the year before. Here’s how it all looks:

Date        Amount  Prior Year  Difference  Percent Savings
02/28/2014  $36.79   $72.91     $36.12	    49.54%
01/31/2014  $40.78   $79.75     $38.97	    48.87%
01/03/2014  $38.86   $67.66     $28.80	    42.57%
12/04/2013  $33.89   $65.84     $31.95	    48.53%
10/31/2013  $27.70   $60.49     $32.79	    54.21%
09/27/2013  $56.45  $112.77     $56.32	    49.94%
08/30/2013  $83.30  $140.69     $57.39	    40.79%
08/02/2013  $34.71  $143.40    $108.69	    75.79%
07/03/2013  $69.41   $78.15 	 $8.74	    11.18%
05/31/2013  $68.00   $70.30 	 $2.30	    3.27%

There are a couple of things to keep in mind here. First off, this is a simple comparison of charges between this year and the last: it doesn’t adjust for variations in weather. A better comparison would be to adjust this by the actual kWh purchased but I didn’t want to get too complicated.
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