How Are Solar Panels Rated? Understanding Solar Panel Output

July 01 2021

Workers installing panels with high solar panel power ratings on a house

Solar panel output indicates the amount of power a panel would produce under ideal conditions. Solar panel power ratings give homeowners an estimate of potential output before they invest.

So, how are solar panels rated? They receive their rating based on the amount of electrical power they generate.

Learn more about solar panel ratings below. Find out which panels offer the highest solar panel output, and how to maximize production from your system.

Solar Panel Power Ratings

Solar panel power ratings, or simply solar panel ratings, are measurements of a panel’s theoretical energy production.

How are solar panels rated?

Solar panels are rated by the amount of DC power they produce in ideal (test) conditions. The more energy they produce, the better. Therefore, high solar panel power ratings are preferable to low ones.

Most modern panels have solar panel power ratings that range from 250 to 400 watts. That means most panels can produce 250 to 400 watts of electricity per hour in ideal conditions. These numbers have increased steadily over the years as solar technology has improved.

Solar Panel Output

Solar panel output is directly related to solar panel ratings. However, other factors affect production as well.

If your panels are rated to produce 300 watts, you can calculate the estimated energy production for your entire system. Most homes get an average of five hours of direct sunlight each day, so multiply 300 watts by 5 hours.

When you do that, you get 1,500 watts per hour, or 1.5 kilowatt-hours (kWh). That means your system as a whole has the ability to produce 1.5 kWh of energy. System pricing is typically measured in dollars per watt, so prices will increase with solar panel output.

Keep in mind that many environmental and site-specific factors also affect solar panel output. Location, shade, weather, and tilt will all play a role.

How Much Electricity Does a Solar Panel Produce?

So, exactly how much electricity does a solar panel produce? As mentioned, average solar panel ratings fall between 250 and 400 watts. That means most panels will produce somewhere between 1.25 kWh and 2 kWh.

The average American household uses 9,000 kWh of energy each year. Producing that amount of electricity would require a system of 17 panels with 400-watt solar panel power ratings.

Keep in mind that solar panel ratings are calculated based on ideal conditions. Not every day will offer ideal conditions. In reality, most homes need between 20 and 25 solar panels to cover 100% of their electricity usage.

If you’re wondering, “How much electricity does a solar panel produce?”, the section above can help you calculate an estimate. However, energy production varies. Many factors affect solar panel output. It is not realistic to expect the same level of production every day.

House with a solar panel system on the roof

Choosing the Right Panels

So, you should just choose panels with the highest solar panel output, right? This isn’t always the best decision. Keep your budget in mind. Prices increase with solar panel ratings.

Plus, there are other factors to consider. For instance, while monocrystalline solar panels are the most efficient panel type, they don’t offer the aesthetic qualities of solar shingles or thin-film panels.

Your location also plays a role. If you live in an area that is ideal for solar production or don’t need to generate a ton of energy, the lower price tag on less-efficient panels is probably worth it.

Not sure what you need? A qualified solar installer can help you make the right choice. Use Greenlife Solar to compare pricing and information on pre-screened solar installation companies in your area. Find the best fit in minutes.

Make the most of your solar investment with a reliable and knowledgeable solar installer. Receive free quotes on each option today.

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