Dear Dot: Does Solar Work on Cloudy Days?



Dear Dot,

What happens when solar panels do not gather enough energy to power the home? Does solar gather power during cloudy/rainy/snowy days or only during sunny days? I wonder how effective solar is on the East Coast compared to the West Coast where there are more sunny days. Thanks. 

—Sam, Brooklyn

The Short Answer: Solar power is like a mail carrier — it delivers through rain, sleet, and snow (admittedly with varying degrees of enthusiasm and efficiency). Unobstructed rays, longer days, and a sunnier locale all contribute to generating more power. But solar power is an option that can work for pretty much anyone. 

Dear Solar-Curious Sam,

Our journalism has been and always will be free.

For as little as $5 per month, you can help us continue to deliver stories that shine light on a better world. Contribute Now.

An app on my phone features a tiny red lightning bolt against a white background. It is called “mySolarEdge,” and when I click on it, I am taken to an image of a tiny cartoon house set in a land of lavender clouds where the sun’s rays are transformed into energy that is charted on a bar graph. I can see, for instance, that on April 18, the solar panels on my roof produced roughly 70 kWh of electricity. The day before, a much cloudier day, it was just over 20 kWh.

I adore that app. It delivers joy right into my orbitofrontal cortex (Eldest Dot Child, a neuroscience Masters student, tells me it’s actually a bit more complicated than that, but for our purposes …). MySolarEdge tells me that 102 trees have been planted since my panels went “live” less than a year ago. These are metaphorical trees, of course. My panels cannot plant trees, but they can do the work of trees, and that’s pretty cool.

I want this joy for you, Sam. I want those metaphorical trees planted for you, too. I want it for all of us. Joy and trees for everyone!

And so let me shed some light on your very good questions  — questions that so many also wonder about — in the hopes that you, too, will become a solevangelist like me. A renewable revolution is coming, Sam, and it’s coming fast. I want you on board that train when it transports all of us to a future in which we meet our Paris climate goals. 

So, first, you ask what happens if solar panels aren’t producing enough energy to power a home.

Most solar panels are tied into a public provider of energy. The energy those panels produce gets sent to the grid, an interconnected system of transformers and power stations and wires that help deliver power to our homes for lights, appliances, and so on. My home’s panels send energy to the grid, which then returns energy to my home according to its needs. If my solar panels aren’t generating enough to power my home — which would typically mean that the panels aren’t sized appropriately to meet my needs, I’ve opted for whatever reason for fewer panels, or maybe I just suddenly have a huge demand for power (I’m operating a grow-op, for instance, though you and I both know Dot would never have done such a thing when it was illegal), or it’s been a long gray winter — we draw power from whatever public utility we’re connected to. 

Currently, however, my panels are producing more power than I require at this time to power my home, which is a common situation. So those of us producing more power than we need send that excess power into the grid to be used elsewhere. We are credited for that power at the rate we would be paying had we been consuming at that time. 

What happens on cloudy days, or at night, when the sun isn’t shining? Good question, Sam! Imagine what happens when you’re sitting outdoors without sunscreen. On a full sunny day, you are likely, if you have fair, freckled Irish skin like Dot’s, to burn quickly. That’s because the sun’s rays are strong and direct. On a cloudy day, however, you might be able to stay out longer before your skin begins to sizzle. The sun is still penetrating, just not as powerfully. At night, of course, no sunscreen is required.

It’s the same for your panels. A full sunny day will produce the most energy, a cloudy day will still allow sun’s rays to hit your panels but won’t produce as much. And at night, my little app tells me that no power is being generated at all. 

Does your geographical location impact how efficiently panels work? It’s a simple equation: The greater the sun, the greater the power generated by solar panels. My panel-topped house is on the East Coast — seven miles off the coast, actually — and New England does not enjoy the solar intensity of, say, New Mexico, or Arizona (the country’s sunniest state). We do, however, enjoy something of a bounty in terms of incentives to adopt solar

So, Sam, solar makes sense even in Brooklyn, since the sun shines as brightly there as it does over the Dot domicile. And if you install solar panels, Dot trusts that the Sun Gods will shine on you and your descendents for eternity for your part in protecting our planet.



Got a question for Dot? Let her know here:

    Latest Stories

    Polar Plunges and Heart-Shaped Kisses

    January really surprised us at our little family farm, with a record-breaking twenty-four inches of snow...

    Can Affordable Housing Be Sustainable, Too?

    Sandywoods Farm in Tiverton, Rhode Island is redefining what affordable housing looks like and how it's designed from the inside out.

    Dear Dot: How Can I Smell Good Without Toxic Chemicals?

    Dear Dot, I like to wear fragrance. Is there a company that will make me smell great...

    RECIPE: Marinated Winter Root Vegetables with Fresh Citrus

    It’s the time of winter when the days are getting longer — but not quite long...
    Dear Dot
    Dear Dot
    Dear Dot is here to answer all your sustainable living questions from her perch on the porch. Got a question for Dot? Send her a note for a chance to be featured in an upcoming post.
    Read More

    Related Articles


    Please enter your comment!
    Please enter your name here