How many solar panels for 2,500 kWh a month?
2,500 kWh a month is 82.2 kWh a day. At 4.5 peak sun hours and 14% losses that takes 21.2 kW: 54 panels of 400 W on 1,117 sq ft (104 m²) of panel area. In a 3.5-hour place it is 69 panels, in a 5.5-hour place 44. The tables below run 3 to 6 sun hours, every US state and the main UK cities at 2,500 kWh a month.
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How many panels for 2,500 kWh a month at 3 to 6 sun hours?
System kW = 82.2 kWh a day / (sun hours × (1 − 14%)); panels = kW × 1,000 / 400 W, rounded up; area = panels × 1.922 m². Find your sun hours in the state and city tables below.
| Sun hours | System kW | Panels | Area (sq ft) | Area (m²) |
|---|---|---|---|---|
| 3 | 31.9 kW | 80 | 1,655 sq ft | 154 m² |
| 3.5 | 27.3 kW | 69 | 1,427 sq ft | 133 m² |
| 4 | 23.9 kW | 60 | 1,241 sq ft | 115 m² |
| 4.5 | 21.2 kW | 54 | 1,117 sq ft | 104 m² |
| 5 | 19.1 kW | 48 | 993 sq ft | 92.3 m² |
| 5.5 | 17.4 kW | 44 | 910 sq ft | 84.6 m² |
| 6 | 15.9 kW | 40 | 828 sq ft | 76.9 m² |
US states: panels for 2,500 kWh a month
Peak sun hours by state from NREL data (Unbound Solar table), the state’s average residential price from the EIA (June 2026). The last column is what 2,500 kWh cost at that price, energy only, before fixed charges.
| State | Sun hours | System kW | Panels | Area | Price | 2,500 kWh cost |
|---|---|---|---|---|---|---|
| Alabama | 4.6 | 20.8 kW | 52 | 1,076 sq ft | 16.4 ¢/kWh | $410 |
| Alaska | 3 | 31.9 kW | 80 | 1,655 sq ft | 28.21 ¢/kWh | $705 |
| Arizona | 6.5 | 14.7 kW | 37 | 765 sq ft | 15.18 ¢/kWh | $380 |
| Arkansas | 4.5 | 21.2 kW | 54 | 1,117 sq ft | 14.12 ¢/kWh | $353 |
| California | 5.6 | 17.1 kW | 43 | 890 sq ft | 34.74 ¢/kWh | $869 |
| Colorado | 5.5 | 17.4 kW | 44 | 910 sq ft | 17.13 ¢/kWh | $428 |
| Connecticut | 4.2 | 22.8 kW | 57 | 1,179 sq ft | 24.32 ¢/kWh | $608 |
| Delaware | 4.4 | 21.7 kW | 55 | 1,138 sq ft | 19.29 ¢/kWh | $482 |
| District of Columbia | 4.4 | 21.7 kW | 55 | 1,138 sq ft | 24.39 ¢/kWh | $610 |
| Florida | 5.3 | 18 kW | 46 | 952 sq ft | 15.1 ¢/kWh | $378 |
| Georgia | 4.8 | 19.9 kW | 50 | 1,034 sq ft | 16.36 ¢/kWh | $409 |
| Hawaii | 5.8 | 16.5 kW | 42 | 869 sq ft | 52.72 ¢/kWh | $1,318 |
| Idaho | 4.9 | 19.5 kW | 49 | 1,014 sq ft | 14.37 ¢/kWh | $359 |
| Illinois | 4.3 | 22.2 kW | 56 | 1,159 sq ft | 19.89 ¢/kWh | $497 |
| Indiana | 4.2 | 22.8 kW | 57 | 1,179 sq ft | 17.51 ¢/kWh | $438 |
| Iowa | 4.4 | 21.7 kW | 55 | 1,138 sq ft | 15.93 ¢/kWh | $398 |
| Kansas | 5 | 19.1 kW | 48 | 993 sq ft | 15.71 ¢/kWh | $393 |
| Kentucky | 4.3 | 22.2 kW | 56 | 1,159 sq ft | 14.26 ¢/kWh | $357 |
| Louisiana | 4.7 | 20.3 kW | 51 | 1,055 sq ft | 13.49 ¢/kWh | $337 |
| Maine | 4.2 | 22.8 kW | 57 | 1,179 sq ft | 29.59 ¢/kWh | $740 |
| Maryland | 4.4 | 21.7 kW | 55 | 1,138 sq ft | 21.84 ¢/kWh | $546 |
| Massachusetts | 4.2 | 22.8 kW | 57 | 1,179 sq ft | 29.61 ¢/kWh | $740 |
| Michigan | 4 | 23.9 kW | 60 | 1,241 sq ft | 22.99 ¢/kWh | $575 |
| Minnesota | 4.3 | 22.2 kW | 56 | 1,159 sq ft | 17.52 ¢/kWh | $438 |
| Mississippi | 4.6 | 20.8 kW | 52 | 1,076 sq ft | 14.88 ¢/kWh | $372 |
| Missouri | 4.6 | 20.8 kW | 52 | 1,076 sq ft | 16.22 ¢/kWh | $405 |
| Montana | 4.7 | 20.3 kW | 51 | 1,055 sq ft | 15.14 ¢/kWh | $379 |
| Nebraska | 4.8 | 19.9 kW | 50 | 1,034 sq ft | 13.25 ¢/kWh | $331 |
| Nevada | 6.4 | 14.9 kW | 38 | 786 sq ft | 13.11 ¢/kWh | $328 |
| New Hampshire | 4.2 | 22.8 kW | 57 | 1,179 sq ft | 27.01 ¢/kWh | $675 |
| New Jersey | 4.3 | 22.2 kW | 56 | 1,159 sq ft | 24.95 ¢/kWh | $624 |
| New Mexico | 6.5 | 14.7 kW | 37 | 765 sq ft | 15.06 ¢/kWh | $377 |
| New York | 4 | 23.9 kW | 60 | 1,241 sq ft | 29.49 ¢/kWh | $737 |
| North Carolina | 4.7 | 20.3 kW | 51 | 1,055 sq ft | 14.74 ¢/kWh | $369 |
| North Dakota | 4.5 | 21.2 kW | 54 | 1,117 sq ft | 14.12 ¢/kWh | $353 |
| Ohio | 4.1 | 23.3 kW | 59 | 1,221 sq ft | 19.19 ¢/kWh | $480 |
| Oklahoma | 5.1 | 18.7 kW | 47 | 972 sq ft | 14.33 ¢/kWh | $358 |
| Oregon | 4.2 | 22.8 kW | 57 | 1,179 sq ft | 16.32 ¢/kWh | $408 |
| Pennsylvania | 4.1 | 23.3 kW | 59 | 1,221 sq ft | 21.73 ¢/kWh | $543 |
| Rhode Island | 4.2 | 22.8 kW | 57 | 1,179 sq ft | 29.23 ¢/kWh | $731 |
| South Carolina | 4.8 | 19.9 kW | 50 | 1,034 sq ft | 15.55 ¢/kWh | $389 |
| South Dakota | 4.7 | 20.3 kW | 51 | 1,055 sq ft | 15.36 ¢/kWh | $384 |
| Tennessee | 4.4 | 21.7 kW | 55 | 1,138 sq ft | 14.07 ¢/kWh | $352 |
| Texas | 5.3 | 18 kW | 46 | 952 sq ft | 15.94 ¢/kWh | $398 |
| Utah | 5.5 | 17.4 kW | 44 | 910 sq ft | 13.37 ¢/kWh | $334 |
| Vermont | 4 | 23.9 kW | 60 | 1,241 sq ft | 24.44 ¢/kWh | $611 |
| Virginia | 4.5 | 21.2 kW | 54 | 1,117 sq ft | 17.22 ¢/kWh | $431 |
| Washington | 3.8 | 25.2 kW | 63 | 1,303 sq ft | 14.91 ¢/kWh | $373 |
| West Virginia | 4.1 | 23.3 kW | 59 | 1,221 sq ft | 15.45 ¢/kWh | $386 |
| Wisconsin | 4.2 | 22.8 kW | 57 | 1,179 sq ft | 19.56 ¢/kWh | $489 |
| Wyoming | 5.2 | 18.4 kW | 46 | 952 sq ft | 15.24 ¢/kWh | $381 |
UK cities: panels for 2,500 kWh a month
Daily irradiation at the optimal tilt from the European Commission’s PVGIS (2005-2020). 2,500 kWh a month is 12 times the Ofgem medium household, so most UK homes need a fraction of these figures; the UK output guides go from the size to the kWh.
| City | Sun hours | System kW | Panels | Area |
|---|---|---|---|---|
| London | 3.48 | 27.5 kW | 69 | 133 m² |
| Brighton (South East) | 3.9 | 24.5 kW | 62 | 119 m² |
| Plymouth (South West) | 3.7 | 25.8 kW | 65 | 125 m² |
| Cardiff (Wales) | 3.47 | 27.5 kW | 69 | 133 m² |
| Birmingham (West Midlands) | 3.27 | 29.2 kW | 74 | 142 m² |
| Nottingham (East Midlands) | 3.3 | 29 kW | 73 | 140 m² |
| Norwich (East of England) | 3.49 | 27.4 kW | 69 | 133 m² |
| Manchester (North West) | 3 | 31.9 kW | 80 | 154 m² |
| Leeds (Yorkshire) | 3.2 | 29.9 kW | 75 | 144 m² |
| Newcastle (North East) | 3.18 | 30.1 kW | 76 | 146 m² |
| Edinburgh (Scotland) | 3.07 | 31.1 kW | 78 | 150 m² |
| Glasgow (Scotland) | 2.88 | 33.2 kW | 83 | 160 m² |
| Aberdeen (Scotland) | 2.98 | 32.1 kW | 81 | 156 m² |
| Belfast (Northern Ireland) | 3.09 | 30.9 kW | 78 | 150 m² |
What the tables leave out
- Orientation and shade: the sun hours assume a south-facing array at a good tilt; east or west roofs get less, and trees or chimneys more. Raise the losses in the panel calculator to see the effect.
- Seasons: a system sized to the yearly use over-produces in summer and under-produces in winter; the output calculator shows the month-by-month split for UK cities and the kWh per kW for every state.
- Money: the payback calculator takes the size from here and adds the cost, the price and the 25-year table.
- Other monthly figures: 1,000 kWh a month, 1,500 kWh a month and 2,000 kWh a month. Going the other way, from a system size to the kWh it makes in the UK: 3 kW, 4 kW and 5 kW.
Sources
US sun hours: Unbound Solar, "Peak Sun Hours by US State", table built from NREL's PVWatts data; "A peak sun hour is one hour of sunlight at an average intensity of 1,000 watts per square meter". UK sun hours: European Commission Joint Research Centre, PVGIS 5.2, PVcalc for the city's coordinates at the optimal slope and azimuth. Panel: A 400 W panel is the middle of the Trina Vertex TSM-DE09 range and the common residential class in 2026; Trina Solar, Vertex TSM-DE09 data sheet, product range 390-405 W. Losses: NREL, PVWatts Version 5 Manual, section 11 System Losses, Table 6. Average US home use: U.S. Energy Information Administration, FAQ "How much electricity does an American home use?". US prices: U.S. Energy Information Administration, Electric Power Monthly, Table 5.6.A "Average Price of Electricity to Ultimate Customers by End-Use Sector, by State, June 2026 and 2025", residential column, cents per kilowatthour, June 2026. UK price: Ofgem, energy price cap unit rates and standing charges, Direct Debit, average across England, Scotland and Wales. UK household sizes: Ofgem, "Review of typical domestic consumption values: decision", Table 1, electricity Profile Class 1, 2026 TDCV. All read 2026-09-20; the full text of each source, with links, is under the calculator.
Frequently asked questions
- How many kWh a day is 2,500 kWh a month?
- 82.2 kWh: 2,500 × 12 months / 365 days. The system has to make that on an average day of the year, which is why the size depends on the sun hours of the place and not only on the use.
- Is 2,500 kWh a month a lot?
- It is 2.8 times the average US home, which the EIA puts at about 899 kWh a month, and 12 times the Ofgem medium UK household (2,500 kWh a year, about 208 kWh a month). At the EIA US average price of 18.34 ¢/kWh it is $459 of energy a month; at the Ofgem cap of 26.32 p/kWh it is £658, before standing charges.
- How many solar panels for 2,500 kWh a month in Texas?
- 46 panels of 400 W (18 kW) at Texas's 5.3 sun hours. The sunniest states in the table, Arizona and New Mexico (6.5), need 37; the cloudiest state in the table, Alaska (3), needs 80. In London (3.48 PVGIS sun hours) it is 69.
- What size solar system do I need for 2,500 kWh a month?
- 27.3 kW at 3.5 sun hours, 21.2 kW at 4.5 and 17.4 kW at 5.5, with 14% losses (the NREL PVWatts default). System kW = daily kWh / (sun hours × (1 − 14%)). The calculator takes your own sun hours, losses and panel wattage.
- How much does a solar system for 2,500 kWh a month cost?
- About $56,160 before incentives at 4.5 sun hours: 54 panels × 400 W = 21.6 kW, × $2.60 per watt (EnergySage US average, June 2026). That size makes 30,511 kWh a year and saves $5,596 at the EIA average price of 18.34 ¢/kWh, a simple payback of 10 years. The IRS says the Residential Clean Energy Credit "is not available for any property placed in service after December 31, 2025", so no federal 30% comes off; the payback calculator takes your own quote, price and any state incentive.
- How much roof space for 2,500 kWh a month?
- The panels alone cover 1,117 sq ft (104 m²) at 4.5 sun hours: 54 × 1.922 m² per panel. Gaps, fire setbacks and the roof's shape add to that. If the roof is too small, cover part of the use (the calculator has a coverage field) or use higher-wattage panels.
More guides
- How many solar panels for 2,000 kWh a month?
2,000 kWh a month is 65.8 kWh a day: 43 panels of 400 W (17.2 kW) at 4.5 sun hours, about $44,720 installed. Every US state and UK city.
- How many solar panels to power a house?
Panels for the average US home (EIA 899 kWh a month) from half to twice that use, every US state, and Ofgem's low, medium and high UK homes in four cities.
- How many solar panels to produce 30 kWh per day?
20 panels of 400 W (7.75 kW) make 30 kWh a day at 4.5 peak sun hours; 25 at 3.5 hours, 16 at 5.5. 5 to 50 kWh a day, every US state and UK city.
- How many solar panels for 1,000 kWh a month?
1,000 kWh a month is 32.9 kWh a day: 8.5 kW of solar, 22 panels of 400 W, at 4.5 sun hours. Sizes at 3 to 6 sun hours, every US state and UK city.
Last updated 2026-10-03. Estimates from published averages (NREL, EIA, Ofgem, industry cost surveys), each with its source and date: an installer's site survey and shading analysis replace them. Not financial advice.