Solar: Annual Savings Estimate

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Production times price equals savings. Multiply the system's yearly kilowatt-hours by the local utility rate and you have the headline number every solar customer wants to see.


Quick formula: Annual production times the rate per kWh:
=B2*C2

12,000 kWh a year at $0.14 per kWh saves $1,680 — the figure that drives the payback conversation.

Functions used (tap for the full reference guide):

The example

Three homes, each with estimated yearly production and their utility rate.

ABCD
1HomeAnnual kWhRate $/kWhSavings / yr
2Home A12,0000.14$1,680
3Home B9,0000.16$1,440
4Home C15,0000.13$1,950

The formula

One multiplication per row:

=B2*C2 // kWh produced x price per kWh

How it works

Savings is simply production valued at the price you would otherwise pay:

  1. B2 is the kilowatt-hours the array makes in a year.
  2. C2 is the utility rate — what each kWh would cost from the grid.
  3. Multiplying them gives the dollars the system keeps off the bill in year one.

Utility rates rise over time, so a multi-year estimate usually grows this figure by 2–4% per year.

Try it: interactive demo

Interactive

Enter annual production and your utility rate.

Variations

Add a yearly rate escalator

Project savings in year N with a rate that climbs each year.

=B2*C2*(1+Escalator)^(N-1)

Pitfalls & errors

Enter the rate in dollars (0.14), not cents (14), or the estimate is 100x too high.

Net metering rules vary — if export credits differ from the retail rate, split production into self-used and exported kWh.

Practice workbook

📊
Download the free Solar: Annual Savings Estimate practice workbook
Edit the yellow Annual kWh and Rate cells; the Savings column recalculates.

Frequently asked questions

Is this the same as my payback period?
No. Divide the net system cost by this annual savings to estimate simple payback in years.
Should I use my current rate or an average?
Use your blended rate (total bill divided by total kWh). Tiered or time-of-use plans need a weighted average.

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Related formulas: Solar: Panels Needed · Markup vs Margin · Cost per Mile

Function references: PRODUCT