Clean Power

Published on February 25th, 2014 | by Guest Contributor


Where The Sun Don’t Shine — Using Solar Power In Darker Climates

February 25th, 2014 by  

Written by David Glenn.

No form of energy takes as much effort to generate as sunlight. To create a single photon of light, the gravitational force at the center of the sun has to create a pressure density of approximately 250 billion times that of the earth’s atmosphere at sea-level. At the same time, the temperature needs to be approximately 16 million degrees Kelvin. This allows some of the hydrogen atoms that make up the sun’s interior to overcome their natural tendency to repulse each other, resulting in hydrogen fusion. The fusion releases an almost unfathomable amount of energy (think E=mc2) in the form of photons. However, the journey doesn’t stop there.


Solar panels under a cloudy sky.
Image Credit: lafoto/Shutterstock.

Ancient Energy

With the incredible density at the center of the sun, and the trillions upon trillions of photons racing about in all directions, it gets pretty crowded. As they bump and bounce off of one another, they very slowly make their way towards the sun’s surface. How slowly? Well, we don’t have all of the facts yet, but it is estimated that the journey of a single photon from creation in the core to expulsion from the solar surface can take anywhere from 100,000 to 1 million years (which means that the stray sunbeam that your house-cat likes to lounge in probably originated back when your cat’s ancestors were still preying on your ancestors). Even after it leaves the sun’s atmosphere, assuming it’s heading in the right direction, it will still take that bit of light another eight minutes to reach the planet earth.

And once it gets here, we generally let it just hit the ground and dissipate as heat. What else can we do? Well, thanks to some very forward-thinking individuals and a little something called the photovoltaic effect, mankind has recently discovered that sunlight can be converted into usable electricity. Silicon solar cells allow their own electrons to be knocked free by the sun’s photons, which can then be turned into an electric current, thus producing a free, clean, and abundant energy source. But let’s take a step back for a moment. What if that photon, after making its 1-million-year (plus eight light-second) journey to earth, never actually reaches the surface and just ends up stuck on the backside of a cloud in the upper atmosphere? How then are we supposed to use it to power our lives?

Solar in the Dark

That’s a question that solar energy enthusiasts are often forced to answer, especially if they live in cloudy or dark climates. Can solar power be used when the sun isn’t shining? What about in colder areas of the world? Let’s take a moment and address these concerns. First and foremost: no, cold weather does not hinder the functionality of solar panels. In fact, the colder it gets, the more freely electricity can flow (thanks to reduced resistance in conductors). So, if the temperatures starts to plummet, solar energy users can keep their homes warm and well-lit, content in the knowledge that their panels are operating at peak efficiency.

Of course, cold weather has some other problems associated with it. If allowed to build up on a solar panel, snow can really hamper energy production by virtue of the simple fact that it prevents sunlight from reaching the panel’s surface. Of course, most panels—if installed correctly—sit at an angle, thus allowing snow to sluff off on its own (or with a little help from a well-placed broom strike). Advances are being made to help keep the paneling clean and unobstructed, such as a miniature, cleaning robots that actually attach to the panels and move freely between them, cleaning up debris and wiping off smudges as they go. So, it’s safe to say that a bit of snow isn’t really worth worrying about.

Creating Solutions for All Climates

And now for the major issue. After all, the sun may shine down equally on both the evil and the good, but it tends to be a bit pickier when it comes to latitude. Depending on the time of year, areas that are far north or far south on the globe may find that the seasons are a bit disproportionate, resulting in nights that can last for over 24 hours at a time, interspersed by only short periods of sunlight. Even locations that are further from the poles can suffer from a lack of sunshine thanks to local weather patterns. Are these locations doomed to rely on conventional energy sources?

Not really. For one thing, the location and angle of a solar panel can go a long way towards making up for lost light. Additionally, motorized panels that adjust to track the sun are also available for cases where it makes financial sense.

At the same time, solar homeowners can use batteries. Batteries allow surplus energy to be stored for use during non-daylight hours. Again, these make sense financially where they beat getting nighttime electricity from the grid. Thanks to falling solar panel prices, falling battery prices, and rising electricity prices, this is an increasingly competitive option. Some think it will be widely competitive within a few years.

Advancing Technology

Current batteries are always being improved upon, and new designs for flow batteries, hydrogen batteries, and even salt batteries are all being developed in the hopes of increasing our potential energy storage capacity. For longer periods of darkness, many solar energy–powered structures are also hooked into the municipal power grid allowing for conventional energy to be used when necessary. And, as an added bonus, many cities will actually buy back any surplus energy that your panels produce, allowing you to use summer sunlight to make up for low energy production during the winter months. And if your home is located near one of the poles and you’re dreading the long dark nights of winter, just remember that once the earth’s orbit takes it halfway around, you’ll be sitting pretty in long days of pure sunlight—it all evens out in the end.

So, even if you live in a less sun-lit part of the world, there are advantages to solar power. Of course, in the end, the choice is still up to you. You can either use the free photons that fly your way, or you can let a million-year journey go to waste.

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About the Author

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  • young learner

    i find this information very useful i know im just doing this cause its part of my science project but i find all the info is very useful for some people i mean im 10 and i just cant stop reading i know you thats not something you hear from a kid a lot but really i find this ready helpful and useful for many reasons and i will say im not the most smartest person in 4th grade but my science teacher said i said i might like it and will make sure to tell her i did find it useful so i hop other people who read this agree

    • Bob_Wallace

      Welcome. Always nice to see more people get interested in how we solve our energy problems.

      Read away. Ask questions if you have them. We’ve got a fairly helpful bunch of contributors here.

      It’s important that we figure out the best solutions and quit using coal and oil as much as possible. If we don’t we are going to leave people your age with some bad climate problems.

      And most of us do not want to do that.

  • JamesWimberley

    A not very helpful article, light on useful facts. Insolation declnes at high latitude: how much? It becomes more seasonal: how much? All we can say without such data is the safe prediction that as pv costs decline, grid parity will move toward the poles. It will also make it economic to cover more orientations, especially west-facing to stretch production into the late afternoon demand peak.

  • David Howes

    Interesting facts about solar energy:
    1- It’s not my wood burning stove that costs a lot, it’s the wood I burn year after year to heat my home (however if it were free and available all the time, that would be another story).
    2 – The cost of solar energy per watt has dropped from $76.67 in 1977 to $0.74 in 2013. Even if these numbers are for the most expensive solar cell in 1977 and the cheapest in 2013, it’s still about 1/100th the cost today as it was only thirty six years ago. If that trend continues (and given the breakthroughs that seem to come every month), solar power should be cheaper than non-renewables in the next five years. Getting it to people is just a mater of logistics, with which we seem to have no problem when it comes to delivering gas and older forms of electrical production. It’s only expensive to get the power to the grid, a one time investment.

    If we were to put solar cells in the many many square kilometers of dessert currently not used by anyone, we’d have more than enough power for all of humanity. It’s silly that we haven’t yet.

    • Bob_Wallace

      Solar is already cheaper than new coal or new nuclear. It’s cheaper than “old” coal if external costs are included.

      Covering large amounts of the desert doesn’t make as much sense as covering rooftops and parking lots. Producing closer to the point of use eliminates transmission issues and puts less strain on the grid.

      Wind and solar are going to win based on bucks.

      • David Howes

        I agree that if we all had solar cells on our roofs, we wouldn’t need huge plants. But the fact is you get more sun in the desert. I like to imagine a happy medium, where we all have solar cells on our roofs to supply us with at least half of our needed energy, with the rest coming from power plants. Then, if there’s a problem at the factory, we all still have lights. still, to power the world with solar power, we’d be silly to not use the desert.
        I read recently about Molten Salt, which stores solar energy in the form of heat, to be able to be used at night.
        Then again, there’s the idea about a floating power plant off shore, utilizing solar, wind, and wave energy? The fact that such a proposal is even feasible is something to be excited about. I’ve no doubts that in 20 years, my daughter’s world will be greatly different than my own.

        • Bob_Wallace

          Take a look at the solar insolation map below. There’s a small Zone 1 area that annually averages 6 hours per day. Outside of Z1 is Zone 2, 5.5 hours per day. The extra 10% in Z1 probably isn’t significant reason to set up PV farms compared to rooftop solar in Z2 and Z3.

          We’re not likely to ship electricity from the SW deserts to other parts of the country. The PNW has lots of hydro and wind. The eastern part of the country is too far away and has their own renewable resources.

      • David Howes

        “Producing closer to the point of use eliminates transmission issues and puts less strain on the grid.”

        It’s noteworthy that the Northeast Power outage of 2003 was caused by a sagging powerline outside Cleveland hitting a tree, causing a cascading power failure that took out over 100 power plants, and effected 55 million people. So I agree, we need to generate power (or at least a good fraction of it) closer to the consumer.

        • Bob_Wallace

          That, and continue to make our grids “smarter”.

          New switching technology can quickly isolate problems and route power for most users around the problem.

          Additionally, we are likely to see storage distributed around the grid giving “neighborhoods” the ability to continue running while supply problems are addressed.

  • Rick Kargaard

    Non of this technology changes the fact that the capital cost is higher for producing enough electricity in difficult climates. Unless there is a significant cost to connect to the grid, it is difficult to acheive reasonable payback times for off grid solutions, or even for microgeneration with a connection to the grid.

  • Gwennedd

    I currently live on the BC coast, where winter is generally cloudy all day for several months. Solar might work during the summer, but it will be abysmal during the winter. I had hoped for using solar AND wind, but this winter was mostly windless. Tidal and wave may be more reliable for our part of the world.

  • Moohamed

    I lived happily off of 540w worth of solar in BC, my average energy generated was 3KwH a day, on really craptastical days the hydro turbine would take over it made 8.4KwH a day seven days a week, till the rain had stopped over a month then it would make 0 (I made the turbine from an old hot tub pump, and some oil filled run caps) and for the most evil of weather (A calm grey day with no rain) a back up generator, mind you it was only run to keep the oil circulated and dry 99% of the time.

    So I’d say it all works great through out most of the weather, like any thing you should never depend on just one source, all ways have two at least, 3 at best!

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