$27,000 Solar System in Denver vs. Ohio: How Group Buys, Net Metering, and Roof Shading Move Payback Between 10 and 16 Years
Your neighbor gets a solar quote for $27,000 and says, "It pays back in 7 years." You get a quote for the same size system and your installer says 12. Neither of you is lying. You just have different utility rates, different export credits, different roofs, and different financing.
This post walks through one 8 kW system in two places, Denver, Colorado and rural Ohio. I built the numbers to show how much each variable moves the answer. The point isn't to predict your payback. It's to show why you can't get an honest number until you plug in your own inputs.
The news that changes the math this month
Five pieces of recent news each touch one input in the payback calculation.
- Solar United Neighbors (SUN) and Rewiring America are hosting a Denver event on September 29 at the Montclair Recreation Center. It covers rooftop solar, batteries, heat pumps, and group purchasing, as reported by Solar Power World. Group purchases change the price you pay.
- Solar Power World's "Home energy sales in 2026" piece describes installers moving beyond panels. Rising utility rates, weaker grid reliability, and EVs mean the pitch is now solar plus battery plus other equipment, not solar alone. A bundled quote can hide the payback of each piece.
- PV Magazine USA's Solargis analysis found that summer 2026 irradiance departed significantly from long-term seasonal averages during a strong El Niño. Production estimates rest on historical sun data, so that assumption matters.
- Solar Power World's wiring basics guide explains how stringing affects voltage, current, and power. This matters for shading, which I'll price out below.
- The 6 MW floating array on Monroeville, Ohio's reservoir (PV Magazine USA) doubled that village's clean energy capacity and saved over 30 acres of land. It's a reminder that shared and community projects are a real alternative if your roof is poor or you rent.
The baseline: an 8 kW system, two places
I'm using round numbers grounded in the kinds of data Elovane tracks. Our analysis draws on 10,850 rows across seven sources, including EIA state electricity prices (3,672 rows), NREL PVWatts irradiance (51 state rows plus 6,287 county rows), and DSIRE incentive programs (171 rows). The inputs below are rounded illustrations, not quotes. Your ZIP code will change them.
| Input | Denver, CO | Rural Ohio |
|---|---|---|
| System size | 8 kW | 8 kW |
| Gross cost | $27,000 ($3.38/W) | $27,000 |
| Annual production | about 12,000 kWh (1,500 kWh per kW) | about 10,000 kWh (1,250 kWh per kW) |
| Retail rate | $0.16/kWh | $0.17/kWh |
| Value of exported power | Assume full retail credit | Assume $0.06/kWh |
| Year-one savings | $1,920 | $1,260 |
Ohio's savings come from a blended assumption. About 60% of production is used at home and valued at $0.17, and 40% is exported at $0.06. That works out to $0.126 per kWh, or $1,260 on 10,000 kWh.
In plain terms, your export credit is what the utility pays you for the extra power you send back. Net metering gives you close to the retail price for it. Avoided-cost credits give you a fraction. The rules vary by state and sometimes by utility. Our state-by-state net metering guide covers the policy side.
I also assume no federal residential credit, since the 25D credit ended for systems placed in service after 2025. Our IRA credits timeline explains what remains. Panels degrade 0.5% per year in every scenario.
Variable 1: Utility rate escalation (2%, 4%, 6%)
Your savings grow if your utility's rates rise. Nobody knows the future rate, so I run three cases. The Denver case uses a group-buy price, which I explain in Variable 2.
Denver at $24,300 (10% group-buy discount), year-one savings $1,920:
| Annual rate escalation | Payback |
|---|---|
| 2% | about 11.7 years |
| 4% | about 10.7 years |
| 6% | about 9.9 years |
Going from 2% to 6% escalation moves payback by about 1.8 years. That's significant, but smaller than what the next two variables do. If your installer's quote assumes 6% or more, ask why. Our 2% vs 6% rate escalation post shows how that assumption alone can swing 25-year results by thousands.
This is the kind of scenario table Elovane runs for you, using your utility's actual rate history, so you don't have to build the spreadsheet yourself.
Variable 2: The group-buy discount
SUN's group purchase programs, like the Denver one, negotiate installer pricing for a pool of homeowners. I'm assuming a 10% discount here. Actual discounts vary by program (one El Paso program, covered in our group-buy vs. tax credit post, ran 23%).
Same Denver system, 4% escalation:
| Price paid | Payback |
|---|---|
| $27,000 (retail quote) | about 11.7 years |
| $24,300 (10% group-buy) | about 10.7 years |
A $2,700 discount buys about a year of payback. Group buys also give you competing bids and vetted installers, which matters after recent installer bankruptcies. Check that the program's price is a true per-watt price and not a headline number with add-ons.
Variable 3: Export credits, the Ohio problem
Now the same $27,000 system in Ohio at 4% escalation:
| Export credit assumption | Year-one savings | Payback |
|---|---|---|
| Full retail credit ($0.17 on all kWh) | about $1,700 | about 12.9 years |
| Blended (60% self-used, 40% exported at $0.06) | $1,260 | about 16.3 years |
Export credit policy alone is worth about 3.4 years. Your payback depends on when you use power, not just how much you make. A household home during the day self-consumes more solar. A household away 9 to 5 exports more.
California's NEM 3.0 works the same way. Export credits dropped sharply, and batteries became part of the answer. See our California NEM 3.0 battery analysis if you're in that state.
The Monroeville project makes a related point. A 6 MW array on a reservoir is a different way to get solar without a rooftop. If your roof is shaded, north-facing, or rented, a community or shared project may beat a bad rooftop, and Elovane can compare them.
Variable 4: Roof orientation, shading, and a bad sun year
Here the El Niño story and the wiring article come together.
Weather. Solargis found summer 2026 irradiance departed significantly from long-term averages. One weak summer is not a 25-year trend. If it cost you 5% of a year's production in Denver, that's about $96. But it shows that "estimated production" is a range. Ask your installer which dataset they used and for the P50 and P90 estimates. P90 is the production you'd beat in 9 of 10 years.
Shading and stringing. In a basic string configuration, panels are wired in series and the weakest panel can drag down the others. Module-level electronics (microinverters or optimizers) reduce that. They cost roughly $0.10 to $0.20 per watt, so $800 to $1,600 on 8 kW. I'll use $1,200.
Say chimney or tree shade costs a string system 8% of annual output in Denver:
- Lost output: 12,000 kWh × 8% = 960 kWh
- Lost value: 960 × $0.16 = about $154/year
- $1,200 add-on ÷ $154 = about 7.8 years to pay for itself
That's a good deal if you're shaded and a waste if you're not. Your shade profile decides which.
Overall underperformance. If Denver produces 15% less than the quote, from orientation, shade, or soiling, year-one savings drop from $1,920 to $1,632. At $24,300 and 4% escalation, payback stretches from about 10.7 to about 12.2 years.
We cover this in more detail in our underperformance payback post. Ask any installer for the production guarantee in writing.
Variable 5: Financing choice
Take the Denver group-buy price of $24,300 and a 15-year loan at 7.5% (the rate is illustrative; check current rates, and Elovane's FRED-based loan rate inputs move month to month).
- Monthly payment: about $225
- Annual payment: about $2,700
- Total paid over 15 years: about $40,550
- Interest: about $16,250
Year-one savings are $1,920, which is less than $2,700 in loan payments. You're cash-flow negative for several years until rate escalation catches up. Over 25 years at 4% escalation, cumulative savings come to about $74,600.
| Path | 25-year cumulative savings | Cost | Net (before inverter replacement of about $2,500) |
|---|---|---|---|
| Cash | about $74,600 | $24,300 | about $50,300 |
| 15-year loan at 7.5% | about $74,600 | $40,550 | about $34,000 |
That's about a $16,000 gap from financing alone. A PPA or lease shifts the equation again, since you skip the upfront cost but give up much of the savings. Our loan vs. lease vs. cash comparison and the 25-year net comparison with no federal credit go deeper. The right choice depends on your cash, your credit, and how long you'll own the house.
The bundle trap: solar plus battery plus everything else
Solar Power World's piece is right that installers are broadening into batteries, EV chargers, and heat pumps. Some of it makes sense, since reliability concerns are real. But each item has its own payback, and a bundled quote can hide a weak one behind a strong one.
A $10,500 battery, for example. Assume 9 usable kWh cycled 330 days a year:
- At a $0.20/kWh peak-to-off-peak spread: 9 × $0.20 × 330 = about $594/year, so about 17.7 years
- At a $0.38/kWh spread: 9 × $0.38 × 330 = about $1,129/year, so about 9.3 years
If you're on a flat rate with full retail net metering, as in my Denver case, a battery may not pay back financially. It could still be worth it for backup power, but that's a comfort purchase, not an investment. Ask for the solar-only quote and the add-on prices separately. Our TOU arbitrage guide shows how to check the spread on your own rate plan.
What the two cases teach
| Scenario (4% escalation) | Payback |
|---|---|
| Denver, group-buy price, full retail export credit | about 10.7 years |
| Denver, retail quote | about 11.7 years |
| Denver, group-buy, 15% underperformance | about 12.2 years |
| Ohio, full retail credit | about 12.9 years |
| Ohio, low export credit | about 16.3 years |
Same system size and same $27,000 sticker price, with a spread of about 5.6 years. No single factor is the villain. Export credits, price, sun, and shade each move things by one to three years, and they stack.
Run these five checks before you sign
- Get your real rate structure. Is it flat, time-of-use, or does it include demand charges? Pull your last 12 bills.
- Find your export credit. Ask what you're paid for each exported kWh, and whether that rule is locked in for the life of the contract or can change.
- Ask for P50 and P90 production and the weather data behind them. A quote based only on the best-case number is a warning sign.
- Get a shade analysis and price module-level electronics against your actual losses, as I did above.
- Compare group-buy, individual, and community options side by side, with cash, loan, and PPA priced for each.
If you're near Denver, the September 29 SUN event is a useful way to see group pricing in person. Wherever you live, bring your bills and your own numbers.
Run the numbers for your house
Everything above depends on inputs that change by ZIP code, utility, and roof. Elovane pulls utility rates, NREL production data, and incentive programs together so you can model your house, not an average one. Try it at Elovane, then compare the result to the quote on your kitchen table. If they differ by years, find out why before you sign.
Data behind this post
The figures above are computed from the product's own reference tables, last refreshed 2026-04-15:
- 3,672 rows from eia_electricity_prices
- 51 rows from nrel_solar_irradiance
- 6,287 rows from nrel_county_solar
- 648 rows from nrel_atb_system_costs
- 171 rows from dsire_incentive_programs
- 7 rows from fred_financial_rates
- 14 rows from nrel_solar_defaults
Sources
- Floating solar array installed on Ohio village reservoir — PV Magazine USA
- Home energy sales in 2026: Why solar companies are expanding beyond panels — Solar Power World
- Solar United Neighbors organizing another group purchase program in Denver — Solar Power World
- Solar panel wiring basics: How to wire solar panels — Solar Power World
- A powerful El Niño season upends global solar resource assumptions — PV Magazine USA