Does my solar roof have to face south?

You don’t need optimal conditions for your solar power system to be a great investment. One of the biggest myths about the financial viability of solar is that it requires a really sunny location and a south facing roof. While these may be ideal conditions, folks outside of Southern California with roofs that face other points on the compass, such as east to west-facing roofs, can still satisfy most of their electricity needs and reap significant financial returns when they adopt solar power systems.


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Which way do solar panels face?

The conventional recommendation is that a roof direction should face south for best exposure to the sun. Though south facing roofs will have the most direct sunlight exposure, the takeaway is that your roof does not have to face south for solar to make sense. Factors like the cost of energy and available incentives will affect your solar economics much more than roof orientation.

South facing roof orientation comparison

solar roof with panels facing south energysage

This beautiful solar roof is facing south into the sunlight but could be equally as efficient with a different roof orientation.

We looked at differences in solar panel production and savings in different areas of the country in our post Top 10 Cities for Solar (Hint:  They Aren’t the Sunniest). But what happens to these numbers when the roof in question doesn’t face south?  We took a closer look at six cities– Boston, Los Angeles, New York, Chicago, Philadelphia, and Washington, D.C.—to see what happens with their solar roofs. Here’s what we found:

Even when solar panels aren’t facing directly south, they can still produce large amounts of electricity, even if you live somewhere that doesn’t receive much sun. In general, regardless of where you live, if your solar roof is oriented directly east or directly west instead of the optimal south-facing, you will only see a 20% decrease in the amount of electricity you produce. Even with this decrease in performance, your solar panels would still produce enough electricity to save you hundreds of dollars a year.




south facing solar roof graphic




Solar panel orientation in cloudy cities

Additionally, lowering the tilt angle of the panels on your solar roof can also contribute to the total economic benefits east and west-facing solar power systems provide. Panels facing directly east or directly west with a 30° tilt, produce about 20% below peak performance levels. If the tilt is dropped to 15°, production levels at the east and west extremes only decrease by about 15%. While this 5% gain may not seem like a significant difference, this slight change in panel orientation can be enough to save an additional $50-$75 per year even in cloudy cities.

Let’s look at Boston to see how the numbers work.  Boston, unlike somewhere like San Diego, is not known for its abundant sunshine, but an average-sized, east-facing solar system in Boston is still capable of producing more than 4600 kWh of usable electricity per year. That’s enough to save more than $650 each year on electricity bills. If you adjust the tilt angle of those panels to 15°, the savings will be between $700 and $725 per year. Those savings in and of themselves are significant, but when you consider that Massachusetts residents qualify for local, state and federal incentives such as tax breaks and solar renewable energy credits (SRECs), the financial returns of adopting solar power, despite the “sub-optimal” conditions become even greater. The point is, you don’t have to have the perfect climate and the perfect south facing solar roof to reap the tremendous financial benefits that solar power can deliver. When it comes to solar, good enough is almost always more than enough.

Three tips for solar shoppers

  1. Homeowners who get multiple quotes save 10% or more

    As with any big ticket purchase, shopping for a solar panel installation takes a lot of research and consideration, including a thorough review of the companies in your area. A recent report by the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) recommended that consumers compare as many solar options as possible to avoid paying inflated prices offered by the large installers in the solar industry.

    To find the smaller contractors that typically offer lower prices, you’ll need to use an installer network like EnergySage. You can receive free quotes from vetted installers local to you when you register your property on our Solar Marketplace – homeowners who get 3 or more quotes can expect to save $5,000 to $10,000 on their solar panel installation.

  2. The biggest installers typically don’t offer the best price

    The bigger isn’t always better mantra is one of the main reasons we strongly encourage homeowners to consider all of their solar options, not just the brands large enough to pay for the most advertising. A recent report by the U.S. government found that large installers are $2,000 to $5,000 more expensive than small solar companies. If you have offers from some of the big installers in solar, make sure you compare those bids with quotes from local installers to ensure you don’t overpay for solar.

  3. Comparing all your equipment options is just as important

    National-scale installers don’t just offer higher prices – they also tend to have fewer solar equipment options, which can have a significant impact on your system’s electricity production. By collecting a diverse array of solar bids, you can compare costs and savings based on the different equipment packages available to you.

    There are multiple variables to consider when seeking out the best solar panels on the market. While certain panels will have higher efficiency ratings than others, investing in top-of-the-line solar equipment doesn’t always result in higher savings. The only way to find the “sweet spot” for your property is to evaluate quotes with varying equipment and financing offers.

For any homeowner in the early stage of shopping for solar that would just like a ballpark estimate for an installation, try our Solar Calculator that offers up front cost and long term savings estimates based on your location and roof type. For those looking to get quotes from local contractors today, check out our quote comparison platform.

5 thoughts on “Does my solar roof have to face south?

  1. Ollie

    Interesting study, although southern facing solar panels obviously still make the most sense if they’re an option. I’d also like to mention that specialized mounting solutions have gotten a lot more affordable and effective over the years. Systems like the one recently developed by TRA Snow and Sun (see here for more info: http://trasnowandsun.com/tra-snow-and-sun-develops-new-solar-mounting-design-for-east-west-facing-solar-mounting-project-in-las-vegas/) allow homeowners with east west facing roofs to still reap the full benefits of solar energy.

    Reply
    1. CharliChuckec

      All true, but the point is that due to the fact that home builders for decades have ignored the orientation of the buildings, South is not an option for many, and if turning the panels on a mount only gains 15%, it may well not be worth it given the aesthetic and mounting costs. In particular, this means that a passive solar air or water heater mounted on an outside wall is very practical–and heat is far more efficient in using solar than PV. Payback on a passive wall heater is under 24 months in many cases. Such a system in snow country, will work fairly even on the north wall, although the payback period will be longer.

      Reply
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  4. John

    It’s really good to know that solar panels can still save you hundreds of dollars a year, even if they aren’t facing south like the article states. My wife and I had looked at switching to solar energy, but I was unsure of whether or not it would be worth it due to us not having a south facing roof. I think even saving hundreds of dollars a year would be really helpful in the long run.

    Reply

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