Escalation sensitivity
| Scenario | Escalation | 25-yr utility spend |
|---|---|---|
| Flat-rate reference | 0.00% | $66,000 |
| Your comparison scenario | 2.50% | $90,176 |
| Proposal assumption | 4.00% | $109,945 |
Compounding added by the proposal escalation: $43,945 above the flat-rate reference.
Proposal vs your comparison scenario: +$19,769 in modeled no-solar utility spend.
Reverse threshold: 4.64%/yr is the bounded non-negative annual escalation at which this simple gross no-solar utility-spend baseline reaches the entered savings claim. It does not reproduce the proposal's solar cash-flow model.
How the two utility baselines diverge over time
This table shows cumulative no-solar utility spend at fixed milestones. It is not annual solar cash flow; it only makes the compounding difference between the two entered utility-escalation assumptions visible.
| Year | Proposal baseline | Comparison baseline | Difference |
|---|---|---|---|
| Year 1 | $2,640 | $2,640 | +$0 |
| Year 5 | $14,299 | $13,877 | +$422 |
| Year 10 | $31,696 | $29,577 | +$2,119 |
| Year 15 | $52,862 | $47,340 | +$5,522 |
| Year 20 | $78,614 | $67,438 | +$11,176 |
| Year 25 | $109,945 | $90,176 | +$19,769 |
Questions to verify in the proposal
- The claimed savings exceed the simple modeled no-solar utility spend under the entered escalation assumption. Ask what additional benefits, incentives, avoided costs or future-load assumptions are included in the claim.
- The proposal and comparison escalation rates differ by at least one percentage point. Over a long horizon, that difference can materially change the no-solar utility-spend baseline used to support a savings claim.
This checker does not predict your actual solar savings. It only compares an installer's explicit long-term savings claim with a simple no-solar utility-spend baseline built from the bill and escalation assumptions you enter. It does not model fixed charges, time-of-use rates, export compensation, future loads, solar degradation, financing, incentives, maintenance or taxes.
What this checker is actually testing
A long-term solar savings claim often depends on a modeled future utility bill. If the proposal assumes electricity prices rise every year, the modeled no-solar alternative becomes more expensive through compounding, which can make the displayed solar savings number much larger.
This tool keeps the installer's claimed savings number fixed and changes only the no-solar utility-spend baseline. That makes the escalation assumption visible without pretending we can reproduce the installer's full proprietary model.
Why two 25-year savings claims may not be comparable
- One proposal may start from a different current utility bill or electricity rate.
- Different annual utility escalation assumptions can create very different future no-solar costs.
- Exported solar may be valued below retail electricity, especially under net-billing structures.
- Fixed utility charges may remain even when solar offsets much of a home's annual energy.
- Panel degradation, inverter replacement, maintenance, financing and future household loads may be treated differently.
- A proposal may define “savings” as bill savings, cash flow, avoided utility spend, or a broader value that includes incentives or other benefits.
Use the original proposal text whenever possible
Home Solar Atlas Quote Analyzer can detect some explicitly labeled long-term savings and utility-rate escalation values in text-based proposal PDFs. Compare Solar Quotes can display those sales assumptions side by side without using them in our own price, readiness or financing calculations.
Solar savings projection FAQ
Are 20-, 25- or 30-year solar savings projections guaranteed?
No. A long-term proposal savings projection is a model, not a guarantee. Its result can depend on the starting utility bill or electricity rate, annual utility-rate escalation, export compensation, solar production, degradation, financing, maintenance, incentives and the proposal's definition of savings.
Why does the utility-rate escalation assumption matter so much?
Because the no-solar utility baseline compounds over a long horizon. Even a modest difference between two annual escalation assumptions can produce a large difference in cumulative modeled utility spend over 20 to 30 years.
Does a higher projected utility bill prove that solar will save that amount?
No. A higher no-solar utility baseline only makes the modeled alternative more expensive. Actual solar savings still depend on how much energy the system produces, how imports and exports are billed, fixed charges, financing and other real-world conditions.
What does the reverse escalation threshold mean?
It is the non-negative annual utility escalation required for this checker's simple gross no-solar utility-spend baseline to reach the entered savings claim. It is a bounded arithmetic reference, not a prediction of future electricity inflation and not a verdict on the installer.
Can Home Solar Atlas verify an installer's full savings model from a PDF?
No. Quote Analyzer can surface some explicitly labeled savings and utility-escalation assumptions from text-based proposals, but the full proprietary model may include many assumptions that are not stated clearly. The original proposal and contract remain the source to verify.
Methodology
The first-year no-solar utility baseline is the entered average monthly bill multiplied by 12. Each later year compounds that annual amount by the selected escalation percentage. The tool sums those annual values over the chosen horizon and compares the installer's explicit savings claim with that simple gross utility-spend baseline.
The result is intentionally not an estimate of actual solar savings. It does not know how much of the bill is fixed, how exports are compensated, how loads change, how solar production degrades or how the proposal handles financing and incentives. Use it to identify assumptions that need explanation, not to certify a salesperson's forecast.