The Sun Number Score is a metric designed to help homeowners assess the potential of their property for solar energy. It takes into account various factors like your building's solar exposure, regional climate, electricity rates, and the cost of solar in your area. But what exactly does this score mean for you, and how can you use it to make an informed decision about going solar? Let's break it down together.
What is a Sun Number Score?
The Sun Number Score is like a report card for your home's solar potential. It's a number between 0 and 100 that reflects how suitable your property is for generating solar power. The higher the score, the better your property is for solar energy. This score is calculated using several factors, including how much sunlight your roof gets, the climate of your region, local electricity rates, and the overall cost of installing solar panels in your area.
Think of it this way: if you're considering a big investment like solar panels, you want to know that it's going to pay off. The Sun Number Score gives you a quick, reliable way to gauge whether solar energy is a good fit for your home.
Components of the Sun Number Score
Now that we know what the Sun Number Score is, let's dive into the different components that make up this score.
Building Solar Score (Maximum score 80 points)
The Building Solar Score is arguably the most significant part of your Sun Number Score. This component evaluates how well your building is positioned to capture sunlight. It considers factors like the orientation and pitch of your roof, any shading from nearby trees or buildings, and the overall surface area available for solar panels. Essentially, it answers the question: how much sunlight can your roof realistically capture?
If your roof is south-facing with minimal shading and a slope that’s ideal for capturing sunlight, you'll likely see a higher Building Solar Score. On the other hand, if your roof is shaded by large trees or has an awkward angle that doesn’t catch much sun, this score will be lower. This doesn't necessarily mean solar is off the table, but it mean you’ll need to get creative with your panel placement or consider some tree trimming.
Recommended reading: Is My Roof Good For Solar
It is worth mentioning that few families can get full marks in this part. Generally speaking, the building score should not be less than 50 points, but it is better to be higher than 60 points.
Regional Climate Score (Maximum score 8 points)
Next up is the Regional Climate Score. This component looks at the amount of sunlight your region receives throughout the year, as well as weather patterns like cloud cover, rain, and snowfall.
For example, if you live in a sunny area like California or Arizona, your Regional Climate Score is likely to be higher because these places receive ample sunlight year-round. In contrast, if you're in a region with long, cloudy winters, like the Pacific Northwest, this score might be lower. The idea here is simple: more sun equals more potential solar energy. You can check out our article: The Best and Worst States for Solar Energy.
For regional climate scores, you can refer to the solar irradiance data on the National Renewable Energy Laboratory (NREL) website to calculate the regional climate score for your area.
Electricity Rate Score (Maximum score 8 points)
The Electricity Rate Score is another key component of your Sun Number Score. This part of the score reflects how much you're currently paying for electricity and how much you could save by switching to solar power. The higher your electricity rates, the more financial sense it makes to invest in solar energy, and the higher your Electricity Rate Score will be.
In regions where electricity is expensive, solar power can offer significant savings, often paying for itself in just a few years. Conversely, if you live in an area with relatively low electricity rates, the financial benefits of switching to solar might be less compelling, which would be reflected in a lower Electricity Rate Score.
Solar Cost Score (Maximum score 4 points)
Finally, we have the Solar Cost Score. This component considers the cost of installing solar panels in your area. It takes into account factors like local labor rates, the price of solar panels and equipment, and any available incentives or rebates.
You can use NERL to look up local solar costs. The lower the local solar costs, the higher the score, and vice versa. A low solar cost score doesn't necessarily mean that solar isn't a good investment. Incentives such as tax credits or rebates can offset the higher upfront costs and make solar more affordable.
Final Solar Score
The final solar score is based on the sum of your building roof, regional climate, electricity costs, and solar cost scores. Few families can get an ideal score of 100 points, but if your total score is over 70 points, it means that installing solar energy is worthwhile.
The following screenshot is a solar score image from Solarreviews, which we used:
Does a Low Sun Number Score Mean Solar Isn’t Right for Me?
A low Sun Number Score can be disappointing, but it doesn’t necessarily mean solar isn’t right for you. This score reflects various factors like roof orientation, shading, climate, electricity rates, and solar costs. While these can impact solar efficiency, they don't automatically rule out solar as an option.
If your score is low due to roof shading or orientation, consider alternative placements like ground-mounted panels. Even in less sunny climates, modern solar panels are effective, so a lower Regional Climate Score might not be a dealbreaker. Additionally, incentives and financing options can offset higher solar costs.
Ultimately, a low Sun Number Score is a starting point—not a final decision. By exploring your options, you might still find solar to be a viable and beneficial investment.
If you are interested in installing solar energy, Shielden can help you assess whether your location is suitable for solar installation as well as provide you with a free solar solution, contact us for the latest solar quote.
