Solar Panels for 35 kWh/Day: Sizing, Cost & Payback (2026)
Est. net savings
$25,300
Over 25 Years (flat electricity rates) · no federal credit
Typical result:
- ~25 panels (400W)
- 9.7 kW system
- ~$26,700 before state incentives
- 10.7–12.4 year payback
25 years without solar vs with solar
Assumes 3%/yr rate increases, 0.5%/yr panel degradation and no federal tax credit (the 30% §25D credit ended for systems installed after Dec 31, 2025). How we calculate
Without solar
25-year utility bills
$51,941
Rates rise ~3% per year
With solar
System cost + remaining bills
$26,675
Installed cost, no federal credit
Difference
Estimated 25-year net
+$25,266
Before any state or utility incentives
How Many Solar Panels Do You Need for 35 kWh Per Day?
Divide your daily usage by your location’s average peak sun hours, then adjust for real-world losses from the inverter, wiring, heat, and dirt. This guide assumes 80% overall efficiency, which is deliberately conservative (NREL’s PVWatts tool defaults to about 14% system losses).
System size (kW) = 35 kWh ÷ (peak sun hours × 0.80)
At the national average of 4.5 peak sun hours, that is 35 ÷ (4.5 × 0.80) = 9.7 kW, or about 25 panels at 400W each (24.3, rounded up).
Solar system size for a 35 kWh/day home, by city
| City | Peak Sun Hours (approx.) | System Size Needed | Panels (400W) |
|---|---|---|---|
| Phoenix, AZ | 6.6 | 6.6 kW | 17 |
| Denver, CO | 5.6 | 7.8 kW | 20 |
| Dallas, TX | 5.5 | 8.0 kW | 20 |
| Atlanta, GA | 5.0 | 8.8 kW | 22 |
| U.S. average | 4.5 | 9.7 kW | 25 |
| Chicago, IL | 4.1 | 10.7 kW | 27 |
| Seattle, WA | 3.5 | 12.5 kW | 32 |
Peak sun hours are rounded annual averages derived from NREL’s National Solar Radiation Database. Different sources round differently and tilt affects results, so confirm your address in NREL’s PVWatts calculator.
Chart summary: The same 35 kWh/day home needs about 6.6 kW in Phoenix but 12.5 kW in Seattle, nearly twice the capacity, purely because of sunlight. Southwest homes land near the low end of the range, while the Pacific Northwest and Great Lakes sit near the high end.
Roof space matters too. A 400W panel typically covers roughly 17–21 sq ft, so 25 panels need about 450–500 sq ft of unshaded roof facing south, west, or east. To check your own numbers, enter your address in PVWatts, or use our solar system size calculator to run the math for your ZIP code.
Run the numbers for your state
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How Much Does a 10 kW Solar System Cost in 2026?
Residential solar in 2026 typically costs $2.50–$3.50 per watt installed, before incentives, according to NREL and marketplace benchmarks, with national averages reported around $2.60–$2.80 per watt. For a 9.7 kW system, that works out as follows.
| Price per Watt | 9.7 kW System Cost |
|---|---|
| $2.50 | $24,250 |
| $2.75 (mid-range) | $26,675 |
| $3.50 | $33,950 |
Because the federal homeowner credit has ended, these are also your net costs before any state, local, or utility incentives (covered below).
Chart summary: The gap between a competitive quote ($2.50/W) and a high quote ($3.50/W) is $9,700 on this system. Comparing dollars per watt across at least three installers is the single easiest way to lower your cost.
Financing. As an illustration, a $26,675 system financed at a 7% APR over 20 years has a monthly payment of about $207, with roughly $22,960 in total interest. A 35 kWh/day household at the 2025 national average rate of 17.3¢/kWh pays about $182 per month for electricity, so the loan payment is slightly higher at first and becomes competitive as rates rise. Check your own loan rate, since it changes the result. Leases and power purchase agreements (PPAs) reduce upfront cost but usually give up ownership and long-term savings, so read the escalator and buyout terms carefully.
For a larger home, see our guide to how many solar panels a 40 kWh/day home needs, and use the solar savings calculator to test your own utility rate.
Solar vs utility company · 25-year comparison
25-year totals: 3%/yr rate increases, 0.5%/yr degradation, no federal credit. Methodology
Total utility payments
$51,941
Total solar cost (installed + remaining bills)
$26,675
Net savings
+$25,266
Avg. monthly difference
+$84/mo
How Long Does Solar Take to Pay Back on a 35 kWh/Day Home?
At the EIA’s 2025 national average residential rate of 17.3¢/kWh, a home using 35 kWh/day (1,050 kWh/month) spends about $182/month, or $2,210/year. A 9.7 kW system in a location with 4.5 peak sun hours produces about 12,750 kWh in its first year, worth roughly $2,205 at that rate.
We modeled payback with these assumptions: $2.75/W installed cost ($26,675), 17.3¢/kWh, and 0.5% annual panel degradation (NREL research finds a median near 0.5% per year). We ran two cases: electricity prices stay flat, or they rise 3% per year. For reference, the EIA national residential average rose from 12.55¢ in 2016 to 17.30¢ in 2025, about 3.6% per year.
Chart summary: With flat rates, the system breaks even in about 12.4 years and ends year 25 about $25,300 ahead. If rates climb 3% a year, it breaks even in about 10.7 years and ends about $48,500 ahead. Either way, the system is a long-term investment, and savings come mostly in the second half of its life.
Rate matters most. Using the same system cost, payback shortens to roughly 6 years if you pay about 33.6¢/kWh, California’s average in July 2026, though California’s NEM 3.0 export rules reduce the value of power sent back to the grid. It stretches beyond 16 years at about 12.7¢/kWh, Louisiana’s July 2026 average. Look up your own rate on your utility bill, then run the solar payback calculator.
Is There Still a Federal Solar Tax Credit? 2026 Incentives Explained
For homeowners who buy with cash or a loan, no. The 30% Residential Clean Energy Credit (Section 25D) ended for expenditures after December 31, 2025, under the One Big Beautiful Bill Act signed July 4, 2025. The IRS states the credit is unavailable for property placed in service after that date. The credit also covered home batteries, so standalone battery storage no longer qualifies either.
What still exists:
- Systems finished in 2025. If your system was placed in service by December 31, 2025, you can still claim the credit, and unused amounts can carry forward to later tax years (see IRS Form 5695 and the IRS credit page).
- Leases and PPAs. Companies that own solar systems can still claim the commercial credit (Section 48E) under current law, subject to construction and in-service deadlines that run through 2027. Whether that benefit reaches you depends on the contract, so ask how it is reflected in your price.
- State credits. New York offers a state credit of 25% of cost, capped at $5,000. Arizona offers 25%, capped at $1,000. Confirm current rules at the state tax agency.
- Property tax exemptions. About 36 states exempt added home value from solar from property tax, either fully or partly.
- Sales tax exemptions and utility programs. Florida, for example, offers sales and property tax exemptions for renewable energy equipment, and many utilities run their own rebates or net metering programs.
A few high-usage states to check closely:
- Texas: No state income tax, so there is no state credit. Ask your appraisal district about the property tax treatment of solar.
- Florida: Tax exemptions apply, and net metering rules vary by utility.
- California: NEM 3.0 reduced export compensation, so self-consumption and batteries matter more for high-usage homes.
- Arizona: A modest $1,000 state credit, plus strong sun that shortens payback.
- New York: The $5,000 state credit is the largest remaining homeowner incentive in many areas.
The federal rules above change often, so confirm details with a tax professional. The DSIRE database lists current state and utility programs, and our solar tax credit calculator can help you estimate what you qualify for.
Is a 35 kWh/Day Home a Good Candidate for Solar?
Often yes. Solar saves money by replacing electricity you would otherwise buy at the retail rate, so a home that uses more electricity has more to offset. The better question is whether your property and utility suit a roughly 10 kW system. Check these three factors.
Roof area and shade. A 9.7 kW system needs around 450–500 sq ft of mostly unshaded roof. If your roof is split by dormers, vents, or trees, ask installers whether microinverters or power optimizers make sense for your layout.
Net metering and export rates. Under full retail net metering, extra spring and fall production offsets summer and winter shortfalls. Under reduced export rates, such as California’s NEM 3.0, you save more by using solar power directly, so sizing near your actual daytime use and considering a battery can make sense.
Usage pattern. Homes with high daytime usage, such as home offices, pool pumps, or daytime EV charging, use more of their own solar output at full retail value.
Simple payback for a 9.7 kW system, by installed price and rate growth (calculated, no incentives)
| Installed Price | System Cost | Payback, Flat Rates | Payback, Rates +3%/yr |
|---|---|---|---|
| $2.50/W | $24,250 | 11.3 years | 9.8 years |
| $2.75/W | $26,675 | 12.4 years | 10.7 years |
| $3.50/W | $33,950 | 16.0 years | 13.2 years |
Payback runs from about 9.8 years (low price, rising rates) to 16 years (high price, flat rates). Price per watt and rate growth move the answer by several years, so a low quote and a high-rate utility give the strongest case.
For homeowners planning to stay at least 10–15 years, solar is usually worth modeling carefully. If you may move sooner, or your rate is near 13¢/kWh, run the numbers before signing anything.
Methodology and Sources
All sizing and payback figures in this guide are calculated estimates, not quotes, and rest on the assumptions stated above (80% system efficiency, 4.5 national average peak sun hours, 400W panels, $2.50–$3.50 per watt, 17.3¢/kWh, 0.5% annual degradation). Your results will differ with roof angle, shade, local prices, and utility rules. This article is general information, not tax or financial advice.
- NREL PVWatts Calculator and the National Solar Radiation Database: peak sun hours and production estimates.
- U.S. Energy Information Administration: average household consumption (2022), national residential electricity price (17.3¢/kWh in 2025), and 2026 state price comparisons.
- IRS Residential Clean Energy Credit: Section 25D status.
- DSIRE: state and utility incentive database.
- 2026 installed-cost ranges ($2.50–$3.50 per watt) drawn from NREL benchmarks and marketplace data such as EnergySage.
Frequently asked questions
Direct answers for US homeowners — sized for a $182/month electric bill.
Same usage, bill-based guide
Your 35 kWh/Day target maps to roughly a $175/month electric bill nationally.
$175 $175/month electric bill guidePopular state solar guides
Electricity rates and incentives vary — see data for your state.
How these numbers were calculated
- Electricity rate
- 18.19¢/kWh — US average residential price. Source: EIA Electric Power Monthly, Table 5.6.B (year-to-date through July 2026), residential average retail price (July 2026) (EIA)
- Solar production
- 4.5 peak sun hours/day × 0.82 system derate. Approximate state-average daily solar resource (peak sun hours) based on NREL solar resource data (NSRDB); not location-specific — use NREL PVWatts for an address-level estimate. (NREL PVWatts)
- Installed price
- $3.00 per watt before incentives. Blended 2026 US residential installed price used by this site; EnergySage marketplace reported about $2.60/W (mid-2026); full-market medians are higher.
- Federal tax credit
- $0 for homeowner-owned systems installed in 2026 — the 30% §25D credit ended Dec 31, 2025 (IRS)
- Net metering
- National blend — solar assumed to offset 75% of the bill (87% in full-retail net-metering states, 55–70% elsewhere).
- Model
- Version 2026.10 · 3%/yr electricity price escalation · 0.5%/yr panel degradation · simple payback = installed cost ÷ year-1 savings
- Policy checked
- · Full methodology · Report an error
Estimates only — not tax, legal or financial advice. Get at least three installer quotes and confirm incentives with your utility and a tax professional.