Balcony solar in Livermore

800 W of panels on a south-facing balcony railing in Livermore produce about 840 kWh a year and save about $141.

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°
East620 kWh1,080 kWh
South-east810 kWh1,270 kWh
South840 kWh1,360 kWh
South-west840 kWh1,300 kWh
West660 kWh1,120 kWh

Output by month

Railing (vertical) Tilted at 30°
Monthly output in Livermore, south-facing0100200JanFebMarAprMayJunJulAugSepOctNovDec
Show as a table
MonthRailing (vertical)Tilted at 30°
Jan93 kWh88 kWh
Feb79 kWh88 kWh
Mar76 kWh110 kWh
Apr67 kWh130 kWh
May49 kWh140 kWh
Jun36 kWh130 kWh
Jul42 kWh140 kWh
Aug61 kWh140 kWh
Sep73 kWh120 kWh
Oct97 kWh110 kWh
Nov87 kWh86 kWh
Dec84 kWh77 kWh

Savings and payback

At $0.3258 per kWh you save about $141 in the first year. A kit costing $1,300 pays back in about 9.2 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 51% of the output is used at home.
  • Power sent to the grid is not paid for.

Calculate with your own figures

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

Full rules for California

Nearby cities

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