How Much Electricity Is Produced by Solar Panels?

The output of a solar panel is measured in watts, so let’s start there. Domestic solar panels typically produce 265 watts of power, although their output can range from as little as 225 watts to as much as 350 watts.

A solar panel’s wattage determines how much electricity it can generate under the same conditions, which can vary depending on where you reside, the angle of your roof, and the compass direction your house faces.

Check out the table below to compare the most powerful solar panels currently available, but be aware that high-power panels may not be right for everyone.

CompanyModelSolar panel power
SunPowerMaxeon 3400W
SolariaPowerXT Pure Black400W
LGNeON® R ACe 380W
SunPowerMaxeon 3 BLK375W
SunPowerX-Series X22 370W
Project SolarEVO Ultramax 345W
PanasonicHIT® N340 340W

How much solar energy is required to power your home?

How much electricity you use and how much of your home you want your solar panels to power are the two key factors in this.

We advise purchasing solar panels with a high output, such as 300 watts (per panel) or more if your household has a particularly high energy consumption or you intend to solely rely on solar panels to power your home.

Solar panels with a lower output, ranging from 225 to 275 watts, are an option if you only need solar power to offset a portion of your home’s energy demand on a daily basis.

A 3-4kWp solar panel system, typically made up of 12–16 solar panels, will be needed for a normal three- to four-bedroom home. Visit our solar panel cost page to learn how much this will cost you.

By dividing the total number of solar panels by their combined wattage, it is possible to determine the output of a solar panel system. A Reading Cardiff home with four 250-watt solar panels, for instance, would have a 1 kW solar system (250 x 4).

According to how much power they require and the size of their roof, the majority of domestic properties have solar panel systems that range from 1kW to 4kW. You can see in the table below how much electricity various solar system sizes typically produce over the course of a year as well as how many solar panels are typically used in each system:

Solar panel system sizeNumber of solar panels
Required roof space
Annual electricity output
1kW
48 sq. metres
850 kWh
2kW
814 sq. metres1,700 kWh
3kW
1221 sq. metres2,550 kWh
4kW
1628 sq. metres3,400 kWh

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How much electricity is generated by a solar panel?

A 3kW or 4kW solar panel system will often produce enough energy for a home that can accommodate a family of three to five people, while a 1kW or 2kW system will be approximately the right size for a couple or single occupant.

The table below illustrates how many hours you may use a variety of home appliances based on how much electricity various-sized solar panel systems typically produce in a year to give you an idea of just how much electricity solar panels can create.

Solar panel system sizeOvenFridge-freezerTVDishwasher
1kW425 hours2,550 hours3,400 hours
850 hours
2kW850 hours
5,100 hours6,800 hours1,700 hours
3kW1,275 hours
7,650 hours
10,200 hours
2,550 hours
4kW1,700 hours
10,200 hours
13,600 hours
3,400 hours

What factors influence the amount of electricity a solar panel can produce?

Your solar panels’ efficiency will decrease if conditions aren’t optimum, which means they won’t be able to produce as much power.

The amount of electricity a solar panel can produce depends on a number of variables. These consist of:

The orientation and pitch of your roof

A solar panel operates most effectively when mounted at a 35-degree angle on a roof with a south orientation. On an east- or west-facing roof, and at any angle between 10 and 60 degrees, solar panels can still provide a respectable quantity of power.

This applies to the majority of homes, which is fortunate because changing the angle of your roof requires a time-consuming, challenging process that calls for a complex frame system and new planning permission.

Shade

Ensure that your solar panels are mounted in full sun, away from any shade. A solar panel’s ability to generate power can be drastically decreased if even a little quantity of shade covers it.

Time of the year

In the summer, when the days are longer and there is more sunlight, a solar panel will generate more power. Solar panels can overheat and can produce less power in temperatures above 25°C.

Dirt

A solar panel’s power production will decrease if it is coated in dirt since sunlight won’t be able to reach the panel.  Make sure you regularly clean your solar panels in the evening with a hosepipe, as long as the jet of water can reach them.

Even though it rains frequently in the UK, don’t rely on the downpours to wipe the dirt away from your panels if they are significantly stained. Instead, consider having them professionally cleaned.

How do you calculate the amount of electricity your solar panels produce?

A metre will be installed in an easily accessible area of your home along with your solar panels. This metre will track how much electricity your solar panels are producing.

You will be able to check how much power your solar panels are producing with the push of a button on your computer or smartphone thanks to certain solar brands‘ recent introduction of online monitoring capabilities.

When solar panels are installed on your roof, it’s simple to forget about them because they essentially require no upkeep. To make sure they’re clean and in good shape, though, we advise inspecting them frequently.

It’s important to keep an eye on your metre periodically to make sure it’s producing the correct quantity of electricity. If the electricity output of your solar panels is very low, there might be a problem.