Pitfalls of online solar calculators.
Solar power is experiencing tremendous growth in Northeast Florida, and A1A Solar recently earned one of the top spots on Jacksonville Business Journal’s list of the fifty fastest growing companies in the city. The surge of interest in rooftop solar over recent years has given rise to a bewildering variety of online solar calculators.
How do they work?
Most online solar calculators are generic, and come up with an estimate without enough data to make the numbers relevant. A homeowner inputs an address and average monthly utility bill, and the calculator spits out a dollar amount along with the number of panels it will take to offset the electric bill.
Relying on one of these calculators for a realistic estimate is like going to Web MD for a serious medical diagnosis. There are too many variables unique to each home which makes these calculators absurdly unreliable. We have experimented with them, inputting our own homes into the calculators, and have yet to find one which is on the money.
What are the variables?
- Utility rates: Rates vary, and unless you know exactly what you are paying per-kilowatt hour, the financial side is going to be completely skewed from the beginning.
- Weather patterns: Some calculators do factor in weather. Cloud cover impacts solar production, and the best online calculators will account for historic weather patterns when arriving at an estimate.
- Shade: Shade has a direct impact on solar production, so knowing how much loss your system will or will not experience due to shading is of vital importance. Most online calculators do not factor in shade at all. Even the ones that do rely on out of date satellite photos, so if a tree has been removed or has grown over the last 5 years, the calculator does not acknowledge the difference.
- Roof: Most online calculators won’t recognize the slope of your roof or any restrictions like shading from chimneys, penetrations by vents, or offsets from the roof. It’s also important to know the type of roof you have. A metal roof requires a different fastening system than a traditional shingled roof. How old is your roof? If you are planning on replacing it within the next few years, you may qualify for a tax credit on the roof if you go solar. The calculator does not know this information.
- Electric panel: Depending on the size of the array you need, an electric panel upgrade may be required. There is no way for the online calculator to calculate this.
- Efficiency measures: If you are a candidate for a hybrid-electric hot water heater, this can offset over ten percent of your usage. The calculator won’t recognize this.
- Historic usage: In Florida, our usage tends to spike during the summer months. When most homeowners use an online calculator, they don’t use an exact number of kilowatt hours used for the year, but instead input a price range for their bill. This creates a great gap between actual usage and the estimated number of panels required to offset the bill over the course of the entire year. The number may be a gross underestimate, or it may swing the other way, depending on the bill amount you use. Either way, it won’t be accurate.
So, how much does it cost?
Even if you are only looking for a ball-park estimate, the only way to answer this question is to sit down with one of our solar consultants. They look for the variables listed above, and have your best interest at heart. Your consultant will design a system just for you and give you an honest price. Each home is different, and each client’s needs vary. You will receive not a ball-park estimate, but rather an exact price. You will also see the return on your investment in terms of monthly cash flow, the increase in value to your home, and the cost-avoidance over time.Your consultant will answer any questions you have, show you how solar works and how much you will save over the lifetime of the system. Each array is designed and integrated individually for every homeowner. Consults are free, and you are under no obligation.
