Comparing Rooftop Solar to Community Solar

This post was written and contributed by Robert Miggins, CEO of Go Smart Solar

First of all, let’s get something straight.  We’re big fans of solar – all kinds.  That said the most frequent questions we get is: “How does Big Sun Community Solar compare to rooftop solar?”  So let’s go through the pros and cons of each.  But before that, a definition. 

Rooftop solar, as the name suggests, means that solar panels are installed on your roof, usually including an inverter attached to the side of your home.  The equipment belongs to you and is typically your responsibility in terms of cleaning and maintenance.  

How does Big Sun work? Just like rooftop solar programs, customers still own their solar panels. Instead of installing solar panels on your rooftop, we install your panels at an offsite location.  We connect directly to the CPS Energy distribution grid and we sell the energy from your panels directly to CPS Energy – every month for 25 years.

Pros to Rooftop Solar

  1. Net metering.  If you were to look at your CPS Energy bill, you’ll see how much they’re charging per kilowatt hour; currently this is 9.8 cents/KWh. As this price goes up, so does the value of the solar you sell back to them. 
  2. Works well with storage. If you want energy storage (batteries) you can connect that to your solar to add resilience to your home. 
  3. Might last longer than 25 years. (as long as you pay to maintain and upgrade the system)

Cons to Rooftop Solar

  1. Holes in your roof.  Usually the only way to attach the panels to your roof is by drilling holes through the roof and into the rafters of your home.  This creates the risk of roof leaks and can void your roof warranty.  
  2. Penalty for overproduction.  As mentioned, CPS Energy buys back at 9.8 cents?  this only stays true if you don’t produce more solar energy than you consume in a 30 day period.  If you produce more energy than you consume, then you only get credited 1.6 cents for all the extra energy.  When consumers want to have a zero charge electricity bill, they will lose money for overproduction. Offsetting 100% of your July bill, for example, usually means you’ll be selling really low cost electricity back to the utility for several other months of the year and this can really lower your payback. Pay close attention to November through February. 
  3. Trees are not as great as you think.  If trees shade your roof, then any solar panels in that spot will be in the shade and underproduce.  You’ll need to trim back or completely chop down your trees (makes little sense, right?)  
  4. Maintenance is on you.  After the rooftop solar is installed, you’re responsible for any maintenance and upkeep.  That means you may need to clean your panels once a year.  More importantly, keep an eye on the inverter to make sure it doesn’t fail (inverters usually last 12-14 years – so sooner or later it will fail).  
  5. Financial risk when moving. Installing rooftop solar panels may not increase the value of your house if you decide to sell. Factors impacting the value of the rooftop solar include if the buyer hires an Accredited Green Appraiser (AGA). If not, the negotiated price may not include the initial rooftop solar investment. Additionally, if the owner finances the rooftop solar system, the lender may put a lien on the house which adds complexity to the transaction.  Removing solar panels on your home can be expensive and never a good idea.   Bottom line: while you are in the house, you’ll definitely see a return from lower electric bills.  Whether or not the next buyer pays you what the are worth is (unfortunately) not clear. 

Pros to Community Solar  [every Con listed above is Pro for community solar]:

  1. There are NO holes in your roof.  Since community solar is not on your roof, there is no risk of leaks. 
  2. Full credit for all energy produced.. If you overproduce in a given month, you will get full credit and that credit over to the next month at full value. 
  3. No need to cut down trees.  Since nothing is on your roof, let them grow. (Yeah, this one makes plenty of sense to us too)
  4. Maintenance, equipment replacement and even hail insurance is included.  Community solar is as hand-free as it gets.  You pay us up front and you’ll never pay another cent for solar for the next 25 years.  Guaranteed.  
  5. Take the credit with you when you move.  If moving, just tell us your new CPS Energy account number and we’ll have them apply the credit to your new bill.  Piece of cake.  

Cons to Community Solar

  1. No net metering.  Instead of earning 9.8 cents per kilowatt hour for your energy, it’s 9 cents.  Pretty darn close but not exactly 9.8. 
  2. Doesn’t create resiliency at home.  Since your system is offsite, the best way to add resiliency to your home is with a gas powered generator.    
  3. 25 year program.  Big Sun and our contract with CPS Energy lasts for 25 years.  That’s also the same length of the warranty you get on a standard solar panel.  At the end of 25 years, the panels still belong to you.  You can come pick them up or we’ll recycle or donate them. And 2.5 decades from now, we expect solar technology to be a lot cheaper and better anyway.
Rooftop vs Big Sun Community Solar

We hope this helps lay out the pros and cons of rooftop and Big Sun Community Solar.