If asked the question, Do solar panels work when it’s cloudy? Yes. they do work when the sun is covered with cloud and the average person would no doubt guess that. So how can they when there’s no sunshine for them to work with?
Actually, that answer is partially true, in that solar panels aren’t as efficient in cloudy conditions as during bright, sunny days.
In fact, the production of solar panels is reduced by at least 50 percent on cloudy days, and may even by down to just 5 to 10 percent of what they can produce on sunny days.
But, the point is that they do still actually do their job, even if at a reduced rate. That’s a great testament to the amazing technology that solar panels are, so let’s look a bit deeper into this.
How Can Solar Panels Possibly Work When It's Cloudy?
You may be wondering how it’s even possible for solar panels to produce any electricity at all on cloudy days.
The answer lies in the incredible technology used by a single solar cell, which takes the light from the sun, or photons (particles of light), and converts that to electricity thanks to silicon in the cells which reacts with the sunlight to generate an electrical charge.
Thanks to French scientist Edmund Becquerel for his discovery of what came to be known as the “photovoltaic effect” in the 19th century!
A number of solar cells are combined to form a solar panel, so that small charge created by a single solar cell is multiplied many times over to produce a significant amount of wattage from a whole panel.
Solar panels perform best in sunny, unshaded conditions, so any type of shading or cloud cover can seriously affect a panel’s performance to the extent that, in extremely cloudy conditions, a panel may only operate at 50 percent efficiency.
Multiply that by however many panels are in an array (an array of panels is basically a group of panels, which is what you normally need to supply enough power to run household appliances, electronics, etc.), and the fall-off in performance can be pretty dramatic.
What Happens If Your Panels Aren't Performing?
If you’re only getting about 50 percent of the solar production of your panels, and that’s not enough to keep your household’s appliances up and running, what can you do?
Well, if you live on the grid, there’s no need to panic, because, thanks to the wonders of net metering, your utility can make up the balance of power and keep your household up and running and all your electrical appliances and devices will keep working as normally.
That’s one of the advantages of having a grid-tied solar electric system, because any time your system runs into trouble and doesn’t produce the amount of electricity needed for a particular task, that’s where your utility comes in and makes up for your system’s shortfall.
Unless you’ve got enough electricity credits banked with your utility company, you’ll be billed by your utility for electricity drawn from the grid at the then prevailing rates, but you’ll never be without power as long as the grid is available.
In case you’re unaware of how grid-tied solar electric systems work, if your system’s producing electricity and it’s not being used by you or your household, that electricity is fed into the grid and your account is credited with that amount of electricity; the more electricity fed from your system into the grid, the greater the amount of credits you’ll accumulate.
If you live off the grid, that’s where your backup energy supplies saved in your battery bank come into play, and your system switches from the electricity produced by your solar panels to the electricity stored in your batteries.
As long as you’ve got enough energy saved up in your batteries, you’ll continue to be able to run your appliances without missing a beat.
Many people living with an off-grid solar electric system also have a generator as an added backup for your battery bank, just in case that runs out of power.
So, the answer to the question “Do solar panels work when it’s cloudy?” is a resounding “Yes!”, but with the proviso that the efficiency of solar panels is reduced substantially, by as much as 50 percent.
That’s where the utility company comes in in on-grid solar electric systems, because it makes up any shortfall in a system’s production capabilities.
And off-grid systems have a battery bank, and often a generator, to provide the electricity that the solar electric system cannot.
In other words, even though cloudy weather does affect a solar electric system adversely, it doesn’t mean you need ever be without electricity to carry on with life as normal, at least electrically speaking.