Balcony solar in El Cajon
800 W of panels on a south-facing balcony railing in El Cajon produce about 830 kWh a year and save about $140.
Output by orientation and mounting
Yearly output with 800 W of panels and the inverter limited to 800 W.
| Panels face | On the railing (vertical) | Tilted at 30° |
|---|---|---|
| East | 600 kWh | 1,120 kWh |
| South-east | 780 kWh | 1,310 kWh |
| South | 830 kWh | 1,410 kWh |
| South-west | 850 kWh | 1,370 kWh |
| West | 700 kWh | 1,200 kWh |
Output by month
Show as a table
| Month | Railing (vertical) | Tilted at 30° |
|---|---|---|
| Jan | 100 kWh | 100 kWh |
| Feb | 89 kWh | 100 kWh |
| Mar | 83 kWh | 130 kWh |
| Apr | 56 kWh | 130 kWh |
| May | 38 kWh | 130 kWh |
| Jun | 28 kWh | 130 kWh |
| Jul | 32 kWh | 130 kWh |
| Aug | 48 kWh | 130 kWh |
| Sep | 65 kWh | 120 kWh |
| Oct | 91 kWh | 120 kWh |
| Nov | 98 kWh | 100 kWh |
| Dec | 96 kWh | 93 kWh |
Savings and payback
At $0.3258 per kWh you save about $140 in the first year. A kit costing $1,300 pays back in about 9.3 years.
- Electricity price: $0.3258 per kWh (U.S. Energy Information Administration, 2025-09..2026-08). Source
- Assumes a constant base load of 150 W, so 52% of the output is used at home.
- Power sent to the grid is not paid for.
Rules
California
Takes effect on January 1, 2027
Up to 1,200 W of inverter output per home.
- Certified as a plug-in photovoltaic system by UL or an equivalent nationally recognized testing laboratory, with a certified feature that prevents backfeeding during an outage; meets the National Electrical Code and the California Electrical Code.
- Your utility may ask you to register the kit.
Last verified: October 31, 2026
Nearby cities
- Chula Vista 810 kWh a year · 13 mi
- San Diego 770 kWh a year · 13 mi
- Escondido 820 kWh a year · 24 mi
- San Marcos 830 kWh a year · 27 mi
- Vista 820 kWh a year · 32 mi
Data sources
- Solar data: PVGIS-NSRDB, PVGIS 5.2, 2011–2015.
- Electricity price: U.S. Energy Information Administration, 2025-09..2026-08.
- Last verified: October 31, 2026
- How we calculate