Electric Bill Savings Calculator

I made a quick Electric Bill Savings Calculator.  In general, for the models I have in this Blog, I designate the input cells in green shading, which is what you should change based on your personal information. Items shaded in yellow are key results or items.

Steps:

1. Enter KWH for each of the past 12 months from your electric bill into cells E9:E20 in the Calculator tab of the model.
2. Enter the estimated solar production KWH into cells E26:E37 in the Calculator tab of the model. Please refer to my post on Solar Home Buyer's Guide Part 2 to estimate your solar production.
3. Change the Region to your location in cell B4 in the Calculator tab of the model. This is based on my utility company Southern California Edison (SCE) - if you click to this link, there are PDFs of the region zones at the bottom of SCE's webpage.
4. If SCE is not your utility, you may need to tweak some items. Override the Tier Rates (cells F4:O4 on the Calculator tab) with your utility rates and tiers. You can either override the Baseline Daily KWH in column C on the Calculator tab or change the amounts in cells B24:C32 on the SCE Tiers tab at the end.

Results:

1. Average annual savings rate per KWH is shown in cell Q38 on the Calculator tab - highlighted in yellow.
2. Annual solar production as a percent of your total electricity usage is shown in cell E39 on the Calculator tab - highlighted in yellow.
3. Annual electricity bill savings as a percent of your total electricity bill without solar is shown in cell P39 on the Calculator tab - highlighted in yellow. You will notice that the $ savings % is higher than the production KWH % for solar. The reason for this is because you are offsetting the highest-priced electric rate tiers with your solar PV system and only paying your utility for the cheapest-priced tiers.
• The tiered pricing is very important in your financial returns. If you are a heavy electricity user (bills that are in Tier 3-5), you are paying hefty prices to your utility. The higher your electricity usage, the more financial sense it makes to go solar.
4. There are several graphical representations of your solar savings in the handful of charts I included in the model. Note that the text boxes in the charts need to be manually updated with the new totals you calculate if you want the charts to be accurate.