How much energy does a solar panel produce?

A solar panel's output might be more than you think.

Written by:
Edited by: Kristina Zagame
Updated Apr 3, 2025
8 min read
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Most of the home solar panels that installers offer in 2025 produce between 390 and 460 watts of power, based on thousands of quotes from the EnergySage Marketplace. Each panel can produce enough power to run appliances like your TV, microwave, and lights. To power an entire home, most homeowners need between 16 to 25 solar panels

A solar panel's output rating, or wattage, is the best indicator of its power production. The amount of electricity your solar panels produce directly impacts your long-term savings—f it doesn't cover your electric bill, it will take much longer to break even on your solar investment...  That's why it’s very important to choose a solar panel model that will generate enough power to offset the amount of electricity you use, especially if you have a small roof. 

We'll help you understand why your roof's square footage, shading, orientation, and sun exposure are important to choosing the right solar panel. You don't want to waste money on high-wattage panels if you don't need them.

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Key takeaways

  • Most solar panels installers offer on the EnergySage Marketplace in 2025 are 390 to 460 watts—expect to see panel outputs in this range in your quotes.

  • Your panels' actual output will depend on your roof's shading, orientation, and hours of sun exposure.

  • The efficiency and number of cells in your solar panels drive its power output.

  • You'll need between 16 and 25 solar panels to cover your home's electricity usage.

Solar panel system size and electricity offset by state

StateAverage system sizeAverage cost of a solar system after incentivesAverage electricity offset percentageAverage cost per watt ($/W)Average 20-year savings

Arkansas

13.11 kW

$22,355

84%

$2.44

$38,041

Arizona

13.34 kW

$19,102

100%

$2.05

$33,286

California

8.9 kW

$14,254

107%

$2.29

$118,316

Colorado

10.47 kW

$20,769

99%

$2.83

$31,793

Connecticut

11.22 kW

$21,889

94%

$2.79

$129,152

Washington D.C.

9.83 kW

$20,740

81%

$3.01

$88,076

Delaware

14.08 kW

$22,170

95%

$2.25

$50,487

Florida

13.11 kW

$21,482

100%

$2.16

$68,751

Georgia

12.45 kW

$22,107

78%

$2.54

$29,423

Iowa

11.23 kW

$23,297

98%

$2.96

$30,753

Iowa

11.23 kW

$23,297

98%

$2.96

$30,753

Idaho

12.8 kW

$22,506

92%

$2.51

$20,419

Illinois

12.02 kW

$23,684

91%

$2.81

$53,878

Indiana

12.61 kW

$25,357

87%

$2.87

$32,530

Kansas

11.88 kW

$24,432

88%

$2.94

$30,220

Kentucky

13.47 kW

$25,050

95%

$2.66

$34,127

Louisiana

10.97 kW

$19,378

75%

$2.52

$24,126

Massachusetts

10.69 kW

$22,750

96%

$3.04

$180,204

Maryland

13.76 kW

$25,511

83%

$2.65

$62,536

Maine

11.7 kW

$24,110

94%

$2.94

$64,483

Michigan

11 kW

$23,878

93%

$3.10

$31,531

Minnesota

11.73 kW

$23,565

92%

$2.87

$42,050

Missouri

12.18 kW

$22,500

89%

$2.64

$35,708

North Carolina

13.96 kW

$22,868

93%

$2.34

$37,659

New Hampshire

10.62 kW

$22,234

101%

$2.99

$97,289

New Jersey

12.7 kW

$23,286

90%

$2.62

$65,668

New Mexico

9.14 kW

$18,433

104%

$2.88

$31,564

Nevada

11.89 kW

$18,453

103%

$2.22

$79,644

New York

11.91 kW

$23,437

91%

$2.81

$49,047

Ohio

12.76 kW

$23,773

91%

$2.66

$65,953

Oklahoma

14.11 kW

$22,849

94%

$2.31

$48,328

Oregon

12.11 kW

$22,590

92%

$2.67

$51,169

Pennsylvania

12.86 kW

$23,565

93%

$2.62

$79,176

Rhode Island

10.24 kW

$22,751

97%

$3.17

$132,200

South Carolina

12.28 kW

$21,662

82%

$2.52

$41,199

Tennessee

13.07 kW

$29,728

79%

$3.25

$15,902

Texas

13.8 kW

$20,191

99%

$2.09

$87,947

Utah

11.77 kW

$21,225

98%

$2.58

$4,290

Virginia

13.43 kW

$26,388

91%

$2.81

$56,794

Vermont

10.95 kW

$22,831

96%

$2.98

$38,528

Washington

13.14 kW

$23,959

78%

$2.60

$24,570

Wisconsin

11.8 kW

$24,729

92%

$2.99

$44,799

West Virginia

14.41 kW

$31,305

87%

$3.10

$69,935

Note: These costs are based on EnergySage Marketplace data. They were last updated on July 15, 2025.

Of all the metrics to look at when you're shopping for solar panels, cell efficiency is one of the most important. The higher a panel's efficiency, the more power it can produce. 

Most solar panels have cells that can convert 17-23% of the sunlight that hits them into usable solar energy. The efficiency depends on the type of cell in the panel. Monocrystalline cells are more efficient and generate more electricity, while polycrystalline cells tend to be more affordable. 

In 2022, researchers at the Fraunhofer Institute for Solar Energy Systems in Germany developed the most efficient solar cell to date at 46.7% efficiency, though it's currently too expensive to be incorporated into solar panels you can buy today. Researchers are constantly working to improve solar cell technology, so we may see higher efficiency panels in the future.

Most home solar panels included in EnergySage quotes today have power output ratings between 390 and 460 watts. The most frequently quoted panels are around 450 watts, so we'll use this as an example. If you live in a sunny state like California, your panel's production ratio is probably around 1.5, meaning a 10 kilowatt (kW) system produces 15,000 kilowatt-hours (kWh) of electricity in a year.

You can calculate your estimated annual solar energy production by multiplying your solar panel's wattage by your production ratio. For example, a 450-watt panel in California will produce about 675 kWh in a year, or about 1.8 kWh daily. That's enough energy to power some small appliances without too much issue.

Quick question

How many kWh will you get out of a full solar panel system?

We looked through thousands of quotes on the EnergySage Marketplace and found that REC Group offers the solar panel with the highest output for homes: 470 watts and 22.6% efficiency.

Highest output home solar panels quoted on EnergySage in 2025

Brand
Solar panel model
Wattage
Efficiency
Size
Output per square foot
REC GroupAA Pure-RX 470W470 W22.6%3.95 x 5.67 ft21
Canadian Solar Inc.CS6.1-54TM-455455 W22.3%3.72 x 5.01 ft20.7
Universal SolarUNI-460-120M-BB465 W21.46%3.72 x 6.28 ft19.9
Q CELLSQ.PEAK DUO 585W585 W21.4%3.72 x 7.93 ft19.8
LA Solar FactoryLS550BL550 W21.28%3.72 x 7.48 ft19.8

*This table only includes solar panel models with over 21% efficiency that are frequently quoted in the EnergySage Marketplace.

quick calculation

How to calculate your solar panel wattage

We often compare solar quotes based on dollars per watt ($/W) to make it easy to evaluate them based on price and power output. A system with higher wattage panels usually costs more than one with lower wattage panels, but it’s worth it  if you need that extra energy to fully cover your electric bills

Let's assume you spend $150 each month on electricity and need a 10 kW system to fully cover your usage. A 10 kW solar installation costs $2.63/W on average, for a total of $18,410 after the federal tax credit. A smaller 7 kW system is about $2.73/W, costing $13,377 after the tax credit.

Without solar, you'd spend $63,267 on electricity over 25 years, assuming an annual inflation rate of 2.72%. With the 10 kW system, your electricity is free, so your only expense is the system cost of $26,300 (pre-incentive), barring some electricity you may have to pull from the grid when your panels aren’t producing. With the 7 kW system, only about 70% of your electricity bill is offset, so you still end up paying $18,980 on electricity over 25 years. The 7 kW system may be cheaper upfront, but you lose out on $13,838 in savings overall.

No solar
7 KW system
10 KW system
Cost per watt ($/W)$0$2.73$2.63
Cost of system after incentives$0$13,377$18,410
Cost of electricity over 25 years$63,267$18,980$0
Total cost$63,267$32,357$18,410

When it comes to solar panel size, bigger isn’t always better. For example, EnergySage ranked the Maxeon 6 as the best solar panel in 2025, but you’ll notice it wasn’t included in the top five highest output panel table above.

The Maxeon 6 only has a power output of 440 W, but it’s a smaller panel (20.79 sq. ft) with a high efficiency (22.8%). This means it generates more power per square foot compared to other panels. If you have limited roof space, it’s worth choosing a smaller, higher-efficiency panel to maximize energy production.

Find out what solar panels cost in your area in 2025
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  • Access the lowest prices from installers near you
  • Unbiased Energy Advisors ready to help
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