Balcony solar savings calculator
Pick your state, set your kit, and see the sum. We use your state's average home electricity price and real sun data, and we show every step so you can check it against your own bill.
Savings for an 800 W kit, by state
Same sums, done for every state: 800 W of panels facing south, all the power used at home, at the state's average price. Real results are lower if some power goes unused or the panels face east or west.
| State (sun data at) | Price / kWh | kWh/yr vertical | Saved/yr vertical | kWh/yr tilted | Saved/yr tilted |
|---|---|---|---|---|---|
| HI (Honolulu) | 47.18¢ | 620 | $293 | 1337 | $631 |
| CA (Sacramento) | 29.75¢ | 819 | $244 | 1320 | $393 |
| ME (Augusta) | 32.11¢ | 742 | $238 | 1046 | $336 |
| MA (Boston) | 30.48¢ | 757 | $231 | 1097 | $334 |
| RI (Providence) | 28.18¢ | 751 | $212 | 1090 | $307 |
| NH (Concord) | 27.64¢ | 738 | $204 | 1055 | $292 |
| NY (Albany) | 28.65¢ | 690 | $198 | 1013 | $290 |
| DC (Washington) | 25.98¢ | 732 | $190 | 1098 | $285 |
| NJ (Trenton) | 24.61¢ | 738 | $182 | 1094 | $269 |
| CT (Hartford) | 24.51¢ | 726 | $178 | 1058 | $259 |
| MD (Annapolis) | 21.40¢ | 752 | $161 | 1132 | $242 |
| VT (Montpelier) | 23.84¢ | 659 | $157 | 959 | $229 |
| NM (Santa Fe) | 16.51¢ | 935 | $154 | 1473 | $243 |
| PA (Harrisburg) | 21.77¢ | 701 | $153 | 1051 | $229 |
| MI (Lansing) | 22.99¢ | 663 | $152 | 1012 | $233 |
| CO (Denver) | 17.17¢ | 887 | $152 | 1310 | $225 |
| WI (Madison) | 19.41¢ | 747 | $145 | 1086 | $211 |
| IL (Springfield) | 19.32¢ | 734 | $142 | 1112 | $215 |
| DE (Dover) | 18.70¢ | 746 | $140 | 1125 | $210 |
| VA (Richmond) | 17.64¢ | 754 | $133 | 1145 | $202 |
| AZ (Phoenix) | 15.05¢ | 877 | $132 | 1446 | $218 |
| IA (Des Moines) | 17.06¢ | 772 | $132 | 1133 | $193 |
| MN (Saint Paul) | 17.20¢ | 766 | $132 | 1082 | $186 |
| OH (Columbus) | 19.38¢ | 666 | $129 | 1036 | $201 |
| WY (Cheyenne) | 14.43¢ | 890 | $128 | 1299 | $187 |
| SD (Pierre) | 15.15¢ | 802 | $122 | 1163 | $176 |
| KS (Topeka) | 15.47¢ | 784 | $121 | 1178 | $182 |
| OK (Oklahoma City) | 14.82¢ | 805 | $119 | 1270 | $188 |
| AL (Montgomery) | 16.33¢ | 724 | $118 | 1189 | $194 |
| IN (Indianapolis) | 17.02¢ | 694 | $118 | 1064 | $181 |
| MO (Jefferson City) | 16.02¢ | 736 | $118 | 1117 | $179 |
| GA (Atlanta) | 15.90¢ | 740 | $118 | 1195 | $190 |
| SC (Columbia) | 15.76¢ | 736 | $116 | 1174 | $185 |
| MT (Helena) | 15.57¢ | 739 | $115 | 1061 | $165 |
| NV (Carson City) | 12.72¢ | 894 | $114 | 1405 | $179 |
| NC (Raleigh) | 14.95¢ | 757 | $113 | 1172 | $175 |
| TX (Austin) | 15.91¢ | 695 | $111 | 1210 | $193 |
| NE (Lincoln) | 13.54¢ | 800 | $108 | 1181 | $160 |
| ID (Boise) | 13.37¢ | 804 | $107 | 1207 | $161 |
| AK (Juneau) | 29.41¢ | 363 | $107 | 498 | $146 |
| FL (Tallahassee) | 14.99¢ | 712 | $107 | 1191 | $179 |
| UT (Salt Lake City) | 13.31¢ | 802 | $107 | 1227 | $163 |
| WV (Charleston) | 16.31¢ | 650 | $106 | 1016 | $166 |
| ND (Bismarck) | 13.31¢ | 790 | $105 | 1113 | $148 |
| AR (Little Rock) | 14.37¢ | 722 | $104 | 1157 | $166 |
| MS (Jackson) | 14.43¢ | 707 | $102 | 1168 | $169 |
| OR (Salem) | 15.92¢ | 635 | $101 | 963 | $153 |
| KY (Frankfort) | 13.80¢ | 681 | $94 | 1060 | $146 |
| TN (Nashville) | 13.42¢ | 688 | $92 | 1086 | $146 |
| LA (Baton Rouge) | 12.87¢ | 694 | $89 | 1186 | $153 |
| WA (Olympia) | 14.63¢ | 598 | $87 | 885 | $129 |
Great Britain (800 W, Ofgem cap)
| City | Price / kWh | kWh/yr vertical | Saved/yr vertical | kWh/yr tilted | Saved/yr tilted |
|---|---|---|---|---|---|
| London | 26.32p | 597 | £157 | 823 | £217 |
| Birmingham | 26.32p | 569 | £150 | 778 | £205 |
| Manchester | 26.32p | 518 | £136 | 710 | £187 |
| Cardiff | 26.32p | 589 | £155 | 826 | £217 |
| Newcastle | 26.32p | 570 | £150 | 760 | £200 |
| Glasgow | 26.32p | 503 | £132 | 682 | £180 |
| Plymouth | 26.32p | 623 | £164 | 880 | £232 |
| Edinburgh | 26.32p | 554 | £146 | 737 | £194 |
Where the numbers come from
- Electricity prices (US): EIA Electric Power Monthly, Table 5.6.A, average residential price by state, August 2026 (preliminary). Read 2026-11-03.
- Electricity price (GB): Ofgem price cap, 26.32p per kWh, direct debit, 1 October to 31 December 2026. Read 2026-11-03.
- Sun data: the European Commission's PVGIS model (version 5.2), which uses NREL's National Solar Radiation Database for US locations and SARAH satellite data for Britain. 1 kW of panels, 14% system losses, facing due south, at each state capital or the named UK city. Read 2026-11-03.
- Raw data files: prices_us.json, yield_us.json, prices_uk.json, yield_uk.json.
Limits: one location per state, so mountain and coastal towns can differ; average prices hide time-of-use and tiered rates; inverter limits (800 W in Britain, 1,200 W in most states) can clip output from bigger panel sets on the sunniest hours. Savings are an estimate, not a promise.