Why Solar Calculators Are Bogus

The solar industry has seen tremendous growth in recent years.  With the rising popularity of solar panel installations, there is a huge need for homeowners and businesses to quantify the costs and benefits of investing in solar energy.  As a result, solar companies have published calculators on their websites that estimate the average cost, incentives, and time to payback.  I think these solar calculators are bogus for a number of reasons.  The biggest reason is most times they aren’t accurate, or let’s say they don’t show the complete picture.

To demonstrate how convoluted coming up with a quote is, let us take a look at the inputs that go into this magic solar calculator:

• Electricity Rates:  To properly evaluate moving to solar power, you must first consider how the installation costs and long-terms benefits compare to your current electricity rates.   Many times, these calculators may use an average rate for the state.  However, electricity rates can vary by utility, and can oftentimes also vary by usage.  In California, they use a tiered system and, in Massachusetts, they have a different rate for peak and off-peak.
  • One solar calculator from a very popular solar website tries to get around this problem by allowing users to pick their town in the state.   I tried to find my town or my utility and I couldn’t find either!
• Solar incentives:  Solar incentives are constantly evolving and quite complex.  In Massachusetts, for example, the rebate can change based on shading, size of the system, income, home value, and if you’re using components from a Massachusetts manufacturer. But wait, if you get power from a Massachusetts municipal utility, then the rebate changes altogether.
  • I didn’t see any of these questions, except utility, when I looked at several solar calculators for Massachusetts residents.
• Size of your system: Most solar calculators measure the size of your system based on your electric bill and the percentage of your usage that you want to offset.
  • In the real world, the size of solar energy systems is limited by either budget or the amount of unshaded roof space you have with the right orientation.

I also think it would be a good exercise to see what is not included in most solar calculators:

• Equipment:   The type of solar equipment (solar panels, inverter) you use can increase or decrease the efficiency of the entire system.  Each solar calculator may have a different measurement of what they think this average efficiency will be, but they do not allow you the choice of choosing equipment.  Equipment choice can also move the price needle up or down.
• Shading:   It would not be in your financial best interest to install a solar energy system that has significant shading because of the loss in production.  In addition, some rebate programs are contingent on reaching a certain production target to receive the full compensation.
• Orientation – The best orientation for a solar array is south, but you can cheat it to the southeast or southwest and still receive good production.  If your roof has the wrong orientation, you may still be a bad candidate for solar and may not reach production targets for rebates.

Ultimately, the best way to get a clear understanding of a potential solar energy system is to speak to a solar installer or contractor who is specifically trained in the intricacies of building the most efficient system leveraging all possible local incentives.  There are some calculators that leverage a satellite picture of your house to estimate the size of the system.  This might be a good start, but it’s still not as accurate as measurements taken right from your site.  Only a proper site evaluation can tell you if you’re a good candidate for solar and what your final costs vs. benefits are.  Please contact our team of solar installers if you’re interested in a free evaluation of your home or business.