Calculator
Virginia solar calculator: when does solar beat your utility?
A solar calculator built on Virginia data. Start with your bill. Add your ZIP for your utility's real average rate and your area's sun. Then drag the slider that everyone argues about.
9.4 kW
System size
13,107 kWh/yr usage
$25,850
Estimated cost
at $2.75/W, cash
$2,362
Year-1 savings
100% of usage offset
10.1 yrs
Break-even
cumulative savings = cost
$70,873
25-year savings
bills avoided + SRECs, nominal
$45,023
Net benefit
savings minus cost, undiscounted
This is a planning estimate, not a quote. Real roofs have real shade, real panels come in fixed sizes, and your utility's bill design matters.
Get a quote for this systemYear-by-year table
| Year | Energy rate ¢/kWh | Solar kWh | Bill, no solar | Bill with solar | Savings | Cumulative |
|---|---|---|---|---|---|---|
| 1 | 15.1 | 13,057 | $2,160 | $188 | $2,362 | $2,362 |
| 2 | 15.6 | 12,991 | $2,219 | $198 | $2,381 | $4,744 |
| 3 | 16.0 | 12,926 | $2,281 | $209 | $2,432 | $7,176 |
| 4 | 16.5 | 12,862 | $2,344 | $220 | $2,483 | $9,659 |
| 5 | 17.0 | 12,797 | $2,409 | $233 | $2,536 | $12,195 |
| 6 | 17.5 | 12,733 | $2,475 | $245 | $2,590 | $14,785 |
| 7 | 18.0 | 12,670 | $2,544 | $259 | $2,645 | $17,430 |
| 8 | 18.6 | 12,606 | $2,615 | $273 | $2,702 | $20,132 |
| 9 | 19.1 | 12,543 | $2,688 | $288 | $2,760 | $22,893 |
| 10 | 19.7 | 12,481 | $2,763 | $303 | $2,820 | $25,713 |
| 11 | 20.3 | 12,418 | $2,841 | $320 | $2,521 | $28,234 |
| 12 | 20.9 | 12,356 | $2,921 | $337 | $2,584 | $30,818 |
| 13 | 21.5 | 12,294 | $3,003 | $355 | $2,648 | $33,466 |
| 14 | 22.2 | 12,233 | $3,088 | $374 | $2,714 | $36,179 |
| 15 | 22.9 | 12,172 | $3,175 | $394 | $2,781 | $38,961 |
| 16 | 23.5 | 12,111 | $3,265 | $414 | $2,850 | $41,811 |
| 17 | 24.2 | 12,050 | $3,357 | $436 | $2,921 | $44,732 |
| 18 | 25.0 | 11,990 | $3,453 | $459 | $2,994 | $47,726 |
| 19 | 25.7 | 11,930 | $3,551 | $483 | $3,068 | $50,794 |
| 20 | 26.5 | 11,870 | $3,652 | $507 | $3,144 | $53,939 |
| 21 | 27.3 | 11,811 | $3,756 | $534 | $3,223 | $57,161 |
| 22 | 28.1 | 11,752 | $3,863 | $561 | $3,303 | $60,464 |
| 23 | 28.9 | 11,693 | $3,974 | $589 | $3,385 | $63,849 |
| 24 | 29.8 | 11,635 | $4,088 | $619 | $3,469 | $67,318 |
| 25 | 30.7 | 11,577 | $4,205 | $650 | $3,555 | $70,873 |
Energy rate = your all-in rate minus the fixed-charge share, escalated each year. Bills include the fixed charges. Dollars are nominal (not discounted).
How it works
Five inputs, no magic.
- Usage = bill ÷ rate. The rate is an all-in average, so this is accurate for annual math even though summer and winter bills differ.
- System size = usage ÷ production per kW. Production comes from NREL's PVWatts for your area (south-facing, 25° tilt), scaled by orientation and shade factors.
- Cost = size × $/W. Minus the federal credit, which is currently 0% for homeowner-owned systems.
- Each year: the energy price grows by the slider; panels lose 0.5%; production offsets usage one-for-one under Virginia net metering; fixed charges stay on the bill; SRECs add a little.
- Break-even is the year cumulative savings pass the system cost. The chart shows the same thing as two cumulative-spend lines crossing. Dollars are nominal, not discounted.
Every constant is listed on the methodology page. See where your rate sits on the rate tracker, what a kilowatt makes in your town, and the payback for an average home at each utility in Is solar worth it in Virginia?
Questions
Where does the electricity rate come from?
By default, Virginia's statewide residential average over the 12 months to July 2026 (16.48¢) from the U.S. Energy Information Administration. Enter a ZIP and pick your utility to switch to its latest annual average. Both are all-in averages before taxes (energy, delivery, riders and fuel adjustments divided by kWh sold), which is the right number for solar math. Co-op rates change mid-year, so the best input is your own bill divided by your own kWh.
Why is there no federal tax credit in the estimate?
The 30% federal residential clean energy credit (Section 25D) ended for expenditures made after December 31, 2025, which the IRS treats as the date installation is completed. Homeowner-owned systems installed in 2026 or later do not receive it. Leased and power-purchase-agreement systems are owned by the installer or financier, who may still claim the separate commercial credit (Section 48E) subject to its own construction deadlines and sourcing rules; whether any of that reaches the homeowner depends on the contract. This is not tax advice. Confirm your own situation with a tax professional.
What is the "rate increases per year" slider doing?
It escalates the energy part of the utility price every year of the 25-year analysis. Virginia's average residential price rose about 3% a year compounded from 2015 to 2025, and faster in the most recent years. Set it to 0% to see the most conservative case; the break-even year moves with it. That is the whole point of the chart: your payback is a bet on this number.
How is the system sized?
Your annual usage is your bill ÷ rate × 12. The system is sized to produce 100% of that using PVWatts production for your area, adjusted for roof direction and shade, capped at 25 kW. Real designs round to whole panels and work around vents and setbacks.
What does the cost include?
A turnkey, roof-mounted system at $2.75 per watt DC, which is in the typical cash-price range for Virginia installers. Ground mounts, batteries, main-panel upgrades and re-roofing cost extra. Adjust the $/W slider to match a real quote.
What do "fixed monthly charges" do?
Your all-in rate is your bill divided by your kWh, so it already contains the basic customer charge. Solar cannot avoid that charge, so the calculator removes it from the rate it applies to the kWh your panels replace. Raising the fixed charge lowers savings a little and lengthens the break-even.
Is this a quote?
No. It is a transparent estimate using published assumptions you can change. A quote comes from a site visit, a shade analysis and a design. If the numbers look interesting, the button under the chart sends your inputs to a Virginia installer for the real thing.