Solar panels and weatherBurning questions

How do solar panels work when there is no sun?

Ten major American cities have solid overcast for more than 180 days a year. Is it pointless to go solar in New York, Seattle or Miami then? Do solar panels work without the sun? Let’s find out.

Solar panels use more than direct sunlight

Schemes - how solar panels work


working capacity of solar panels on a cloudy day

Your solar system works best when sunlight falls directly on it. PV modules can also capture indirect sunlight reflected, refracted, and scattered by the Earth’s atmosphere. They make use of a broad spectrum of light, including ultraviolet and infrared radiation not seen by the human eye.

Сlouds still diffuse and absorb some of the sunlight, making it less intense and decreasing power generation. Solar panels work at 60% to 80% of their capacity on a cloudy day.

Want to learn more? Check out our guide on how solar panels work!

Consider battery backup for cloudy days

When you don’t get enough energy from solar panels, you can simply draw it from the grid. In an off-grid system, you have to get batteries to power your home at night or on cloudy days. 

You can build a hybrid system by adding batteries to a grid-tie installation. This will protect you from power outages. The US has already experienced over 60 power disturbances in 2023, according to the EIA

There are two common types of batteries for solar systems — lead-acid and lithium-ion.

Lead-acid batteries are time-tested, widely available, and relatively affordable. They last for 3-12 years, depending on the maintenance. The efficiency of lead-acid batteries floats around 80-85%. Their energy density is low: 50-100 Wh/kg, which means that a high-capacity battery occupies a lot of space.

Lithium-ion batteries are efficient and durable. They last for 10-15 years and are less vulnerable to extreme temperatures, deep discharge and overcharging. Their efficiency reaches 95%. High energy density of 100-265 Wh/kg made them a popular choice for consumer electronics and EVs. 

The choice between lead-acid and lithium-ion batteries depends on factors like your budget, the climate in your area, and the purpose of the energy storage. Before purchasing, check out our article on how to figure out the right size of your battery bank.

Find your best solar batteries

Keep the sun on 24/7 with a reliable energy storage bank. Don’t let power outages change your plans!


Years of experience in translation and a love of nature help Julia find the right words to encourage going solar. She joined the team in 2023 and is happy to make her contribution to a greener future.

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