How accurate are online solar panel calculators

On many solar installation websites, you’ll find online calculators that help you determine your potential energy savings and costs.

Some even help you predict your carbon offset (i.e. how much smaller your carbon footprint will become).

But how accurate are solar panel calculators?  Can you really get detailed and truthful information from these online tools?

Yes and no.  Let’s review.

Online Solar Panel Calculators Are Useful, But…

These online tools are really helpful when you have absolutely no idea what your rooftop’s energy potential is.

If you’re starting from scratch, a solar panel calculator can give you ballpark figures of:

  • carbon offsets
  • electricity bill savings
  • earning potential

But basing your decision to go solar (or not go solar) on these calculators can be a mistake.  Even the best online tools are simply “guestimates.”  They can sometimes overestimate your energy potential.  But they can also underestimate as well – often by a lot.

Why so much variation?

Solar panel calculators use satellite imagery to generate their results.  This approach has several limitations:

  • Satellite maps don’t always show the correct house.  If you’ve ever used GPS technology or Google Maps, you know this already.
  • Satellite maps can’t show shading.  If you have a lot of trees surrounding your home, this can negatively impact the total power output of your system.
  • Although satellite maps can determine the size and orientation of your roof, they cannot determine the actual slope and tilt (which are just as important).  In addition, obstacles (antennae, chimneys, vents, etc.) are difficult for satellite maps to weed out.
  • Many solar calculators base their estimates on standardized panel arrangements (i.e. 3kW or 5kW).  But you might be better off with a 4.2kW or 5.6kW system.  Click here to learn more.
  • Even the best calculators become less accurate with time.  That’s because incentives and utility rates constantly change.

Use Solar Calculators for Your Initial Research Only

Again, solar panel calculators are perfect for doing surface research.  But don’t base your decision 100% on the numbers that they spit out.

The best way to determine whether solar is right for you is to request a free estimate from a licensed contractor.

Most solar installation companies in San Diego will send teams to your property to do detailed inspections of your home’s solar potential.  And thereafter, they’ll give you solar proposals that outline everything you need to know – including:

You shouldn’t have to pay anything for this service – so steer clear of San Diego solar installers who try to charge you.

If you’re ready to begin exploring your solar options, contact us today for a free at-home inspection.