Is solar power a good option for traffic products in cold climates?

3 min. read

Where do you think some of the best places in the world for generating solar power exist? Mexico? Australia? Brazil? Making a guess on a country with a warm climate and year-round sunshine is a completely logical answer. Would it surprise you to know that this list ranking the countries in the world with the most solar capacity names Germany, China, and Japan as the three highest producers of solar energy megawatts per year? Notably, none of the top three destinations are renowned for sunny climates.

Despite common belief, solar powered traffic control devices can run just as efficiently in mid-latitude locations with cold, gloomy winters as they can in low-latitude locations with consistently sunny weather. Actually, unlike thermal technologies that rely on the sun’s heat to function, solar panels actually operate more efficiently in cooler weather.

This article will help dispel the myth that solar power only works in sunny locations. For the vast majority of locations, from Everett, WA to  Woonsocket, RI, to not-so-sunny Vancouver, BC, solar power not only works, but offers one of the most sustainable, cost-effective, and easy-to-install energy systems  available. What follows are some tips on how to put solar to work on the roadways in your community, no matter where you live.

Solar sizing matters

When it comes to solar power systems, there is no such thing as one size fits all. Finding the right mix (and size) of solar panels and batteries is key to having a sustainable product that meets individual project requirements—get either piece wrong and you could find your traffic beacon or LED sign, dark.

Proper solar sizing takes a variety of factors into account, but one of the most important is project location. Since a sunny southern city like Miami receives a lot more sunlight than a northern city like Toronto, the size of the solar array and the battery capacity requirements will be vastly different for each location. A system sized for Miami won’t cut it in Toronto—but that doesn’t mean solar is off the table.

To ensure your traffic safety device can generate and store enough power to sustain the requirements of any location, it’s essential to build enough solar and battery capacity into your system. That may mean adding more solar panels or larger batteries, or possibly selecting a more power-efficient product. Read more about how to properly size your complete solar engine, including solar panels, batteries and high-intensity LEDs to ensure you have enough backup power to carry you through inevitable periods of bad weather.

Calculating solar sustainability

Don’t worry – this isn’t going to turn into a math class!  However, if you want to understand the key factors that drive this sizing balance, here they are in a nutshell:

  • Factor #1: The amount of energy a system can collect must exceed the amount it uses to run the beacon or sign every day. This is called the array-to-load ratio (ALR). Read more here.
  • Factor #2: The solar panels must be large enough to recharge your battery bank every day – even during the shortest days of the year. Properly sized panels will ensure the longest lifecycle possible for your batteries and that the system will not fail due to a lack of power.
  • Factor #3: Some back-up power should be built into the battery bank – this way, the system will continue to operate reliably, even if there are unforeseen issues. This is called system autonomy.
  • Factor #4: Small amounts of shading from trees or building can significantly reduce the amount of energy a solar panel can collect. Other than removing branches, a shade de-rating value should be considered at an individual site. A solar-powered product manufacturer should be providing this value for you, along with a full solar-sizing report.

Factors to understand energy in calculation

 Factors to understand energy out calculation






What about snow and solar power in cold climates?

Winter weather is a challenging issue in many parts of North America and Europe, but with the correct installation of high quality, durable panels, poor weather will not affect the performance of your system. Yes, if there’s two feet of snow covering your panel, the system isn’t going to generate much power, but installing the panel at a 45 degree angle encourages most snowfalls to slide or melt off before obstructing performance. And if it doesn’t? That’s where backup power comes in.


You don’t have to live on an island in the sun to enjoy the many benefits of solar power. Northern locations in Canada, the United States, and many European countries are excellent proof that reduced sunlight and winter weather do not limit the effectiveness of solar. Requesting the advice and assistance from technical experts at Carmanah will help you find the best solution for your solar requirements. It’s what we do, and we love it!

Learn how we build an Solar Power Report for any traffic system we sell – in warm or cold climates.

Learn more about how to keep your solar powered traffic devices connected and operating at their top performance with StreetHub™ Remote Connectivity.

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