How Much Does Balcony Solar Save per Month? Real Numbers by State

Short answer: a typical 800 W balcony solar kit produces about 600 to 1,400 kWh a year and saves roughly $6 to $18 a month in most states, averaged over the year. In high-price states it's more: about $18 to $29 a month in California. At around $900, the kit pays for itself in 3 to 13 years, depending mostly on your electricity price.

Every savings figure on this site comes from one simple formula. Once you understand it, you can judge any claim you see in an ad.

Savings = kWh produced × share you use yourself × your price per kWh

1. How much an 800 W kit produces

Production depends on three things: how sunny your state is, how the panels are mounted and how much shade they get. Using rounded NREL PVWatts-style estimates, an 800 W kit produces:

• Tilted about 30° toward the south, no shade: 920 kWh a year in Washington state up to 1,400 kWh in Arizona.
• Vertical on a south-facing railing, light shade (the typical balcony): about 30 to 40% less, or 580 to 880 kWh a year.
• Vertical facing east or west: roughly half of the tilted figure.
• Facing north: usually not worth it.

Output also swings with the seasons. For a typical mid-latitude US city, an 800 W kit producing 1,040 kWh a year might make about 55 kWh in December and 115 kWh in July. Vertical panels lose less in winter, when the sun is low, and more in summer.

2. How much of it you actually use

Most US plug-in solar laws exclude these kits from net metering, so electricity your home isn't using at that moment goes to the grid without credit. Your fridge, router and standby devices (often 100 to 300 W) soak up the first few hundred watts all day. Above that, it depends on whether you are home:

• 400 W kit: usually 90 to 100% self-use.
• 800 W kit: 70 to 90% in a lived-in home, less in an empty one.
• 1,200 W kit: 50 to 75% unless you have big daytime loads like AC.

Shifting the dishwasher, laundry and EV or e-bike charging to sunny middays raises your share, and so does a battery. More on that in which size you need.

3. Savings and payback by state

The table uses each state's average residential price (EIA, July 2026), 80% self-use and a $900 kit. Payback is shown from the best case (tilted, no shade) to the typical balcony (vertical, light shade).

Not every state in the table allows plug-in solar yet (Hawaii, Massachusetts, Pennsylvania, Illinois, Arizona, Texas, Florida and Washington had no law in October 2026). Check the state map. To divide by month, use twelve: an $130-a-year kit saves about $11 a month on average, more in summer and less in winter.

Worked example: a New Jersey apartment

Two 400 W panels on a south-facing railing, an 800 W microinverter, light shade from the balcony above:

1. Production: 0.8 kW × 1,300 kWh per kW (New Jersey, tilted) × 0.7 (vertical) × 0.9 (shade) ≈ 655 kWh a year.
2. Self-use: someone works from home, so about 80% is used: 525 kWh.
3. Savings: 525 kWh × $0.252 ≈ $132 a year, or about $11 a month.
4. Payback: $900 ÷ $132 ≈ 6.8 years. Panels last 25 years or more; microinverters are typically warranted for 10 to 15.

How to save more from the same kit

• Tilt the panels if your balcony allows it: a 20 to 30° tilt can add 30% or more over vertical mounting.
• Avoid shade. Even partial shade on one cell can cut a panel's output sharply.
• Run big appliances at midday when the panels are producing.
• Check your rate. If you're on a time-of-use plan, solar power is worth less at midday than the evening peak, which is where a battery can help.

For your own numbers, use the balcony solar savings calculator. For the bigger picture, including when it isn't worth it, read Is balcony solar worth it?

Frequently asked questions