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
Data approachEIA rates · NREL sun hours · 2026 federal policy · methodology
Most bungalows that use about 8,000 kWh a year need 11 to 18 solar panels (400W each), or roughly 4.4–7.2 kW, depending on how sunny the location is. In 2026 a typical 6 kW system costs about $15,000–$21,000 before state and local incentives. The federal 30% homeowner tax credit ended on December 31, 2025, so your electricity rate and local incentives now drive the payback.
The sizing math depends on three inputs: your annual kilowatt-hour (kWh) use, the peak sun hours at your address, and the wattage of the panels you choose. Get those three right and the panel count is straightforward.
Last updated: October 1, 2026.
⚡ System Size
How Many Solar Panels Does a Typical Bungalow Need?
Use this formula: Annual kWh ÷ (peak sun hours × 365 × 0.80) ÷ panel kW = number of panels. The 0.80 factor is a system-efficiency (derate) allowance for inverter, wiring, temperature, and soiling losses. A 400W panel is 0.4 kW.
The U.S. Energy Information Administration (EIA) reports that the average U.S. home uses roughly 10,800 kWh a year. A smaller single-story bungalow often uses less. This guide uses 8,000 kWh a year (about 667 kWh a month) as a reference load so the cities below can be compared directly. Peak sun hours are rounded, city-level averages from NREL-derived data; your own address can differ, so check it in PVWatts.
Panels Needed for an 8,000 kWh/Year Bungalow (400W Panels)
Location
Peak Sun Hours/Day (approx.)
kWh per 1 kW per Year
Panels Needed
System Size
Phoenix, AZ
6.5
~1,898
11
4.4 kW
Miami, FL
5.3
~1,548
13
5.2 kW
Kansas City, MO
5.0
~1,460
14
5.6 kW
Boston, MA
4.2
~1,226
16
6.4 kW
Portland, OR
3.8
~1,110
18
7.2 kW
Panel counts are rounded to the nearest whole panel and assume a 0.80 system-efficiency factor, a south-facing roof, and little shading.
Data visualization
Panels needed by city. An 8,000 kWh/yr bungalow needs 11 panels in Phoenix, AZ and 18 in Portland, OR. Source: NREL-derived peak sun hours, GreenEnergyCalc calculation 2026.
Chart summary: The bar colors run from green (fewest panels) to red (most panels). For the same 8,000 kWh/year bungalow, sunshine alone changes the panel count from about 11 in Phoenix to about 18 in Portland, Oregon, roughly 64% more panels. Boston and Portland homeowners should plan for a bigger array, or accept a lower share of their usage offset. If your bungalow uses more electricity, scale these numbers up in proportion.
If your home has electric heat, a heat pump, an electric water heater, or an EV, add that usage to your annual kWh before you size the system (see the next sections). Use our solar system size calculator to enter your own usage and location.
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💰 System Cost
How Much Does a Solar System Cost for a Bungalow in 2026?
U.S. residential solar typically costs $2.50–$3.50 per watt installed in 2026 before incentives, according to several 2026 cost surveys and Lawrence Berkeley National Laboratory’s Tracking the Sun data. Prices run higher in states such as California and Massachusetts and lower in competitive markets such as Texas, Florida, and Arizona.
Bungalow Solar System Cost Before Incentives (2026)
System Size
Approx. Panels (400W)
Low ($2.50/W)
High ($3.50/W)
4 kW
10
$10,000
$14,000
5 kW
12–13
$12,500
$17,500
6 kW
15
$15,000
$21,000
7 kW
17–18
$17,500
$24,500
Data visualization
Installed cost by system size. A 6 kW system costs $15,000 to $21,000 before incentives. Source: 2026 US installed-cost range of $2.50 to $3.50 per watt (LBNL, industry surveys).
Chart summary: Every extra kilowatt adds about $2,500–$3,500 to the price. A 6 kW bungalow system lands between $15,000 and $21,000, and the gap between a low and a high quote on the same system is $6,000. That is why getting at least three quotes matters.
The federal credit change. The 30% Residential Clean Energy Credit (IRC Section 25D) no longer applies to homeowner-owned systems for expenditures made after December 31, 2025, per the IRS. Third-party-owned systems (leases and power purchase agreements) may still benefit from a commercial credit under Section 48E, which can affect lease and PPA pricing. It is not a credit you claim yourself.
State and local help still exists. For example, New York offers a state income tax credit of 25% of system cost, capped at $5,000 per residence, as described by the NY Department of Taxation and Finance. A number of states also exempt the added home value from property tax. Check your state and utility on DSIRE before you request quotes. For a full cost breakdown by state and system size, see our guide to How Much Do Solar Panels Cost in 2026?.
What Size Solar System Does a Bungalow Actually Need?
For most bungalows the answer lands between 4 kW and 7 kW. A 400W panel produces about 525 kWh a year at 4.5 peak sun hours (0.4 kW × 4.5 × 365 × 0.80), roughly 760 kWh in Phoenix and 445 kWh in Portland, Oregon. Divide your annual kWh by that number to get a panel count.
Reference system used in this guide: 8,000 kWh a year, 4.5 peak sun hours, 400W panels. That works out to about 6.1 kW, or 15 panels (6.0 kW), producing about 7,900 kWh a year, which covers roughly 98–99% of the reference load.
Things that push the size up:
An EV. Driving 12,000 miles a year at about 0.3 kWh per mile is roughly 3,600 kWh, or about 7 extra panels at 4.5 sun hours.
Electric heating, a heat pump, or an electric water heater. Add their annual kWh from your bills or the equipment label before sizing.
Pool pumps, hot tubs, or window A/C units.
Things that let you size down: attic insulation and air sealing, LED lighting, and efficient appliances. Use your last 12 months of bills as the baseline rather than a rule of thumb.
Should you oversize? Panels lose roughly 0.5% of output per year, so a 10–15% cushion can offset degradation and leave room for an EV later. Check first: some utilities limit system size to your historical usage, and under net billing the extra production may earn only a low export rate. Adding panels later usually costs more per watt than including them at installation.
📈 Payback Period
How Long Does Solar Payback Take for a Bungalow?
Simple payback is the system’s net cost divided by its first-year savings. For the reference 6 kW system, we assume a price of $17,400 ($2.90 per watt), production of about 7,900 kWh a year, and every kWh credited at the retail rate.
Payback of the Reference 6 kW System by Electricity Rate (No Incentives)
Residential Rate
Year-1 Savings
Simple Payback
13¢/kWh
about $1,025
about 17.0 years
15¢/kWh
about $1,183
about 14.7 years
18¢/kWh (about the U.S. average)
about $1,443
about 12.1 years
25¢/kWh
about $1,971
about 8.8 years
30¢/kWh
about $2,365
about 7.4 years
Data visualization
Cumulative cash flow, 6 kW system. A $17,400 system reaches break-even in about year 13 at 18.3 cents per kWh and about year 9 at 25 cents. Assumes 0.5 percent yearly degradation, flat rates, no incentives. Source: EIA 2026 rates, GreenEnergyCalc calculation.
Chart summary: The blue line is the cumulative cash flow at the U.S. average rate of about 18.3¢/kWh, and the orange line is at 25¢/kWh. Each line starts at -$17,400 and crosses zero at about year 13 (blue) and about year 9 (orange). After 25 years the totals are roughly +$16,600 and +$29,000. These figures assume 0.5% yearly degradation, flat electricity rates, retail-rate credit for every kWh, and no incentives. The U.S. residential average was about 18¢/kWh in mid-2026 per EIA data, and state averages range from about 13¢ to well over 30¢ (California was near 35¢). State incentives shift each line upward; weaker export credits shift it down.
25-year view. With 0.5% annual degradation and flat 18.3¢ rates, the reference system produces about 185,700 kWh over 25 years, worth about $34,000. After subtracting the $17,400 price, net savings are roughly $16,600. That ignores rate increases, maintenance, and a likely inverter replacement, so treat it as a rough benchmark, not a guarantee.
Net metering and net billing. Under traditional net metering, exports offset your bill at or near the retail rate. A growing number of utilities and states now pay lower export rates (California’s net billing program is the best-known example), which lengthens payback unless you use more of your solar power at home or add a battery. Check the current rules for your utility on DSIRE.
Is Solar Worth It for a Bungalow? Key Factors to Check Before You Commit
Solar still makes financial sense for many bungalows, but five factors can change the answer.
Your electricity rate. As the payback table shows, a 25¢+ rate roughly halves the payback of a 13¢ rate. If your rate is low and no incentives apply, consider a smaller system or efficiency upgrades first.
Roof condition and age. If your roof needs replacing within the next several years, replace it before installing solar. Removing and reinstalling panels adds cost and is often not covered by the solar warranty.
Shade and orientation. Even partial shading can reduce output noticeably on a string-inverter system. Microinverters or power optimizers can reduce that loss for an added cost. Ask your installer for a shading analysis and a production estimate for your exact roof.
Your utility’s export policy. Confirm whether you get retail-rate net metering, time-of-use net billing, or a lower avoided-cost credit, because it changes the payback by several years.
Financing. For a $17,400 system, a 12-year loan at 6.5% APR runs about $174 a month, compared with roughly $120 a month in estimated bill savings for the reference bungalow. Cash purchases pay back fastest, and a loan reduces the upfront cost but adds interest. Compare cash, loan, and lease or PPA offers on total cost over 20–25 years.
The bottom line: if your roof has good sun exposure, your electricity rate is above the national average, and your utility offers fair export credits, solar can pay for itself well within its 25-year warranty period. In lower-rate areas, the case depends on local incentives. Run your own numbers with our solar ROI calculator before you sign anything.
Sources and Methodology
Residential electricity prices: U.S. Energy Information Administration, Electric Power Monthly (2026 releases).
All panel counts, costs, and payback figures on this page are calculated by the editorial team from the stated assumptions (400W panels, 0.80 system-efficiency factor, 0.5%/year degradation, flat electricity rates) and are estimates, not quotes or guarantees. This page is general information, not tax or financial advice.
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Most bungalows need 11 to 18 panels (400W each), or about 4.4–7.2 kW, to offset roughly 8,000 kWh a year. Phoenix needs about 11 panels, Kansas City about 14, and Portland, OR about 18. The formula is annual kWh ÷ (peak sun hours × 365 × 0.80) ÷ 0.4 kW. If your bungalow uses 6,000–9,000 kWh a year, expect about 11–17 panels at 4.5 peak sun hours. Your last 12 months of utility bills are the most reliable input.
Without the federal credit, a $17,400 six-kW system saving about 7,900 kWh a year pays back in about 12 years at the U.S. average rate of roughly 18¢/kWh. At 25¢–30¢/kWh the payback is about 7–9 years, and at 13¢–15¢/kWh it is about 15–17 years. These figures assume every kWh is credited at the retail rate, which is not true under every net-billing program, so confirm your utility's export rules.
It can be, but it depends on your electricity rate, roof, and local incentives. The Section 25D homeowner credit ended for expenditures after December 31, 2025. For the reference six-kW system, the 25-year net savings come to roughly $16,600 at today's flat rates, before any rate increases, maintenance, or inverter replacement. State incentives such as New York's 25% credit (up to $5,000) improve the numbers. Homes with low rates or heavy shading may not break even comfortably.
A purchase (cash or loan) gives you ownership and any state incentives. As an example, a $17,400 system financed at 6.5% APR for 12 years costs about $174 a month, versus roughly $120 a month in estimated savings, so you pay about $54 a month net during the loan. Leases and power purchase agreements (PPAs) may reflect federal credits the installer can still claim on third-party-owned systems, but check the escalator, contract length, and transfer terms. Compare total cost over 20–25 years, not just the first monthly payment.
Yes. East- and west-facing roofs typically produce somewhat less than a south-facing array, often in the range of 10–20%, and many installers add a few panels to compensate. North-facing roofs and heavily shaded roofs are the weak cases. Ask your installer for a shading and production estimate (for example from NREL's PVWatts) for your exact roof before you sign.
Same usage, bill-based guide
Your For A Bungalow target maps to roughly a $100/month electric bill nationally.
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).
Estimates only — not tax, legal or financial advice. Get at least three installer quotes and confirm incentives with your utility and a tax professional.