250-watt solar panels: what to know

What can 250-watt solar panels run?

Although 250-watt solar panels don’t have as much power capacity as other panels on the market today, that doesn’t mean they’re a bad choice for your solar installation. When interconnected to a battery system or solar generator, arrays of 250-watt solar panels can essentially run any electrical item. (However, the number of panels you’d need for larger installations may be prohibitive.)

For smaller, DIY systems, 250-watt solar panels are a bit of a happy medium. 250-watt panels can generate decent amounts of electricity but are more affordable than most higher-powered modules. While 50-watt or 100-watt panels could save you some money upfront, 250-watt solar panels can make much more efficient use of the space on your roof or property.

How many 250-watt solar panels do you need?

When determining how many solar panels you need, the answer will depend on how much electricity you plan to use. Based on the average American household use of about 886 kilowatt-hours per month in 2021, or about 10,630 kWh over the year, you would need a significant number of 250-watt panels to run all your home’s electrical amenities.

Although you could technically power your home with 250-watt solar panels, you may not have enough room for the 40 solar panels it would take to completely offset your home’s electricity use. While some homeowners are lucky enough to have ample sun-facing roof space clear of obstructions and shade, many property owners are limited to smaller installation spaces.

Let’s consider what that means when you’re working with 250-watt solar panels, which have average dimensions of 3.25 feet by 5.5 feet (covering about 18 square feet each). You would need roughly 720 square feet of usable roof space to install a 10-kW system, which many residential properties simply don’t have.

» MORE: Solar panel size and weight: a guide

How much energy can a 250-watt solar panel produce?

The amount of power a 250-watt panel can produce each day is mostly dependent on the amount of sun exposure it receives. Expected daily sunlight hours vary across the U.S., averaging between three and five hours per day. For instance, people in Boston can expect three and a half hours of peak solar potential every day, while Austin, Texas, averages around five sunlight hours per day.

Multiply the wattage of your solar panel by your expected number of sunlight hours to calculate each panel’s theoretical daily output.

However, many other factors influence your system’s ability to generate power, including the equipment’s age, your local weather and how efficient your solar panels are at converting sunlight into electricity.

“Say the input rate of solar energy from the sun to a solar panel is around 1 kilowatt per square meter, or 1,000 watts; a solar panel might convert 15% to 20% of that into electricity,” said Gavin Harper, a research fellow at the University of Birmingham in England.

So, while installed on the roof of your home, cabin or RV, a single 250-watt solar panel exposed to 4.5 hours of sunlight can be expected to theoretically generate 1,125 Wh per day. However, with real-world factors at play, actual production is going to be much lower — closer to an average of 750 Wh per day.

» LEARN: How do solar panels work?

Are 250-watt solar panels right for you?

In summary, 250-watt products are some of the best solar panels for small, DIY installations. Both relatively powerful and affordable, 250-watt panels can generate sufficient amounts of electricity for RVs, cabins and other off-grid uses, but they may lack the power necessary to make sense for an average American household.