Is It Possible for Solar Panels to Charge in the Moonlight?

Michael Pollick
Michael Pollick

Solar panels depend on direct sunlight in order to produce electricity. Generally, solar panels do not charge in the moonlight. Raw sunlight contains a number of energized particles, including the all-important photon. When photons from the sun strike one side of an array, they essentially cause electrons to break off from one panel, cross a thin membrane, and attach themselves to another panel. The crossing of the freed electrons is what generates a usable electrical current.

Solar panels require sunlight to charge.
Solar panels require sunlight to charge.

If there are no photons striking the panels, the electrons remain in place and no electricity is generated. This is why dark clouds or nightfall are so problematic when generating solar power on a commercially viable scale. When the sunlight disappears, so does the electricity. The electricity produced during daylight hours is not lost forever, however. The excess electricity is stored in large batteries and can provide power during overnight hours.

The moon can only reflect light and does not emit light as the sun does.
The moon can only reflect light and does not emit light as the sun does.

The main reason standard solar panels cannot charge in the moonlight is the nature of the moon's light. Unlike the sun, the moon does not generate its own light energy. What people see on Earth is the sun's light energy reflecting off the moon's surface. A solar panel array placed on the moon would generate electricity during Earth's nighttime hours because it is receiving direct sunlight containing photons. The reflected light seen from Earth does not contain a significant number of photons, so in most cases, moon light will not cause the panels to generate electricity.

This is not to say that the power of the stars could not be used to generate electricity on Earth. A material sensitive to stellar energy, visible or invisible, could be used to create "stellar panels," which could supplement solar cells by generating electricity at night or on cloudy days. The current limitations of such an alternative energy source are financial and technological in nature. A material capable of converting stellar energy into electricity has yet to be perfected, and the initial cost of building a usable array would be prohibitive.

There are reports about a proprietary material developed by Russian scientists that can convert stellar energy into electricity 24 hours a day. This "heteroelectric" material is said to be less expensive to produce than standard solar cells, and has an efficiency rating of 90%, compared to the 10-12% efficiency rating of silicon-based solar panels currently in use. So even though most solar panels in use today are not able to use moon light or stellar energy for electricity, this does not mean that it will not become a reality in the near future.

Michael Pollick
Michael Pollick

A regular EasyTechJunkie contributor, Michael enjoys doing research in order to satisfy his wide-ranging curiosity about a variety of arcane topics. Before becoming a professional writer, Michael worked as an English tutor, poet, voice-over artist, and DJ.

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Discussion Comments


I recently had solar panels fitted. We know ours are a good quality and like the ones used in Scandinavia, they operate during lower light levels than many solar panels but we were surprised the other night we had a really bright strong moonlight and noticed the Solar Power meter was whizzing around collecting KW hrs at 11 pm. In England In March!


The source of the light is irrelevant! All that matters for the solar panel to be active at all (and it depends on the technology, e.g., silicon or thin-film) is the wavelength of the incident light.

The brightness determines the amount of current generated, i.e., the power level.

Our eyes adjust to different lighting levels automatically to a certain extent, so we are unaware of just how much brighter daylight is compared with moonlight.

The inverter unit to which the solar panels are attached will usually not trigger and start operation until the power available from the panels reaches a certain threshold, even though the panels might be generating a small amount under moonlight.


anon332157: No, your feed in tariff would have to be more than $2 per kwh for this 'political perpetual motion machine' to yield a profit, even with the best light source and solar panels around today. You'd generate less than 25W, much less if the cells are packed less than 100%. But it would work, the free energy nuts are going to explode with excitement.


If photons are photons, reflected or not, and it's more or less a matter of intensity of concentration (direct from sun being more intense than reflected from moon), I would be curious whether or not some setup using a fresnel lens and/or a parabolic mirror to gather from a larger area and concentrate it onto a pv panel would cause an appreciable improvement in utilization of lunar reflected light.


If "light is light and all light consists of photons" then, if I receive a feed in tariff of 44 cents per kwh from my 10 kw solar panels (Generating approx 45 kwh per day) and pay 23 cents per kwh I use from my local electricity supplier (which I currently do), I could use a 250 watt spotlight and shine it on a set of 10 kw solar panels at night for 10 hours at a cost of 23 cents per kwh or 58 cents per night. I could turn this into a more profitable setup than it currently is. Does anyone know how many kwh each night it would generate?


Whoever wrote that is in correct. There are sprays out there that allow solar panels to collect energy at night. It may be a small amount, but there is still ultraviolet radiation and other forms of radiation that continue at night that when set up can also be used to create energy.


We have a 10KW PV on the rooftop of our workplace. Most nights, it'll be in hibernation state, as the panels aren't generating anything. However on a clear night with a full moon, we'll see the system kick on and generate 15-20 watts.

I assure you, PV panels can energize from reflected moonlight.


i think the moonlight can produce power but in small quantities, so a powerful detector is required.


@Anon111384- I would take the claims of Frogs Leap with a grain of salt. I would agree with you that you can receive a slight charge from a full moon, but nowhere near what the sun would be. Direct sunlight in the tropics is about 250 watts per square meter (averaged over night and day, without accounting for cloud cover). The moon only produces 0.00146 watts per square meter of direct light energy when measured from sea level in the tropics with the moon directly overhead.

The difference between the radiation from the sun and the moon in the tropics is over 170,000 times. This would make it physically impossible for a solar electric panel array rated at 135 kW to pull five or six kW from the light of a full moon. This represents a difference of only 27 times, nowhere near the ratio of 170,000+ to 1 that would be possible. The theoretical maximum (not taking into account things like temperature, air density, etc.) would be more along the lines of 0.8 watts (0.008kW) from this array.


There are some great kits available for those interested in building solar panels. You can find kits as cheap as a few hundred dollars if you’re handy with tools and can follow the instructions easily.

The basic concept is the same for building the solar electric panels. You should install them on your roof or in your backyard facing south to capture the light from the sun. You can choose to use them as partial electric generators for your house, or to completely power your house, effectively allowing you to live “off the grid.”


@MrMoody - I’m going to have to disagree with you, and agree with anon111384 on this one. There is no qualitative difference in the light. It is in fact quantity rather than quality that matters.

Moonlight generates very little light in comparison to the sun, so the solar panels capturing moonlight will produce miniscule amounts of electricity, too small to make it worthwhile. Solar panels will always be "solar" panels for this reason, and never "lunar" panels.


This is a brilliant analysis on the difference between moonlight and sunlight – the former is reflected and the latter is direct. I had not thought about this before. It’s not that I ever believed solar energy panels could be charged at night, I just wasn’t sure exactly why.

If asked, I would have told you that the evening light was simply insufficient, in other words, there wasn’t enough of it – but not that there was a qualitative difference in the light.


I beg to differ. Light is light. Light consists of photons. PV professionals talk about "albedo" radiation, which is light scattered by the atmosphere, clouds, suspended particulates, etc. PV panels can reach operating voltage on a cloudy day, however, less current is produced relative to direct irradiance from the sun.

The difference is quantitative, not qualitative -- the PV modules will respond to any form of light, it's just that direct sunlight is a much richer source of photons. Frogs Leap Winery in California claims that their 135 kw PV array produces five to six kw in the light of a full moon. Cheers, citizen dave

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