Do solar panels work at night?

Outside of being one of the best ways to power your home sustainably, solar panels are limited by one key factor: they have a relatively restricted time window in which they can work.

In this article, we'll explore why solar panels aren't equipped to work after dark and how you can still make the most of your solar at night with a battery.

If you’re wondering how much a solar & battery system could save you, answer a few quick questions below and we’ll provide you with an estimate.

Can solar panels produce energy overnight?

Despite their advanced technology, modern solar photovoltaic (PV) panels cannot produce energy overnight. They rely on natural light to generate electricity, so they only work in the daytime.

As a result, if you plan to make maximum use of your solar panels (and you don’t have a battery), it’s wise to shift most of your electricity usage to daylight hours.

You can set many appliances - like your washing machine or dishwasher - on a timer, so they operate when your solar panels are generating the most electricity (which is usually around midday). 

Automating appliances means your solar panels will cover a great proportion of your electricity needs, saving you from resorting to more expensive grid electricity in the evening.

That said, there are exciting changes on the horizon. Researchers at the University of New South Wales (UNSW) in Australia are developing a new technology that could generate electricity at night - but more on this further down.

What about moonlight?

Solar panels only need ambient light to function, which is why they still work well on cloudy days and during grey winters. So in theory, moonlight (i.e. reflected UV light from the sun) should technically be able to trigger the photovoltaic effect.

However, the amount of light reflected by the moon is tiny - only about 0.0002% of the intensity of direct sunlight. This means that while solar panels can technically use moonlight to produce some electricity, it’s barely a hint.

It’s also not even enough electricity to trigger most solar inverters' startup voltage, which is the minimum amount of power required to get an inverter working. And without an inverter, your solar panels’ DC electricity can’t be converted into AC electricity. 

So the wisp of electricity produced by solar panels under the moonlight doesn’t get converted into a usable form, and is lost.

Can you use solar power at night?

As we've established, solar panels can only generate electricity when there's daylight. However, you can still use your solar panels’ electricity after sunset - just add a storage battery.

Without a battery, if your home doesn’t use the electricity your solar panels produce in the instant that it’s generated, it will automatically be exported to the grid (and you’ll get paid for it via a solar export tariff). But chuck a battery into the mix, you can store up your excess electricity for later use. 

Having a solar battery significantly increases your energy independence and boosts your savings. In fact, with a solar & battery system in the UK, you can cut your electricity bill by 86%, on average. 

This figure is based on a sample of over 150 systems installed by Sunsave across England and Wales in 2024. The average system is 6.1 kilowatt-peak (kWp), with 54% of solar electricity used at home and 46% exported to the grid. 

That said, during the darker winter months, you’ll still need to rely on the grid for some of your overnight electricity needs - even with a battery. In the UK, only about 11% of a solar panel’s annual output is generated in the winter (compared to almost 40% in summer).

Overnight battery usage during summer

A new 'night-time' solar technology

In 2022, an award-winning team of researchers from Australia's University of New South Wales (UNSW) developed a new technology capable of generating electricity at night.

The researchers successfully converted infrared heat into electricity using a thermoradiative diode - a semiconductor device constructed of materials common in night-vision goggles - which replicates the Earth’s natural nocturnal cooling process.

Associate Professor Ned Ekins-Daukes explains that the process still relies on solar power, which warms up the Earth during the day with sunlight. At night, this heat energy escapes into space as infrared light, and the diode can harvest this energy.

"Using thermal imaging cameras you can see how much radiation there is at night, but just in the infrared rather than the visible wavelengths. What we have done is make a device that can generate electrical power from the emission of infrared thermal radiation," says Ekins-Daukes.

Although the current power output is relatively small, at around 100,000 times less than a standard solar panel, the researchers are optimistic about improving the technology.

Healthcare applications of this technology could mean bionic devices, like artificial hearts, which use body heat as a power source instead of batteries - an amazing future possibility.

Research paper co-author Dr Michael Nielsen remarked: “Even if the commercialisation of these technologies is still a way down the road, being at the very beginning of an evolving idea is such an exciting place to be as a researcher.”

It's still in experimental stages and not yet available to the public, but it represents a promising step towards round-the-clock solar generation.

The problem with solar farms on dark days

Solar panels' poorer performance in low-light conditions points to a larger problem facing the UK’s ambitions for Net Zero.

Naturally, large-scale solar farms struggle to produce much electricity when it’s dark and gloomy - such as during 'dunkelflaute' events, where periods of low sunlight and low wind simultaneously decimate the output of solar farms and wind farms. 

To tackle this, we need a major increase in our battery storage capabilities, so that we can save up our excess renewable energy for these dunkelflaute events. 

The government plans to expand the UK's energy storage capacity to 30GW by 2030 (a considerable increase from the current 4.7GW) using technologies such as battery storage, pumped storage, and liquid air energy storage.

And, thankfully, progress on that has already started. In January 2025, Doncaster Council gave a Yorkshire-based battery storage project the green light, and it's set to become the largest in the UK at 1.4GW of capacity.

However, storage alone isn’t enough. The UK also needs to make electricity demand more flexible to help balance supply and demand in all conditions. This is achievable through demand flexibility services and decentralised storage from both electric vehicles (EVs) and household batteries.

Next steps

Solar panels are a marvellous piece of human ingenuity, but unfortunately they can’t generate electricity at night (yet). However, by adding a battery to your solar PV system, you’re able to use your panels’ electricity once the sun has set. 

There are also ongoing developments that could eventually pave the way for 24/7 electricity generation from solar energy, thanks to the researchers at UNSW. Although it could be a seriously long time until this technology is going up on rooftops - residential or otherwise.

If you’d like to find out how much a solar & battery system could save you, simply click the button below, provide a few quick details, and we’ll provide you with an estimate.

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