How much energy does a solar panel produce?

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.

Solar panel system size and electricity offset by state

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.

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

*This table only includes solar panel models with over 20% efficiency that appeared in at least three Marketplace quotes.

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 2.8%. 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.