Four years with solar power


Electricity generated from solar power offset yearly usage by 104%.  We used 5,119 kWH / year (averaged over nine years).  Our 4.3 kW system generated 5,338 kWH / year (averaged over four years).

I still clearly remember when the solar carport was built as if it were yesterday, yet it’s been four years.  As a new year dawns, I wanted to plot our average electricity generated and benchmark relative to the original PVWatts estimate made (and posted below) before the panels were installed.

I am now even more in awe of PVWatts.  As you can see from the graph, the yellow curve is the estimated generation, based on our location, solar array size and panel angle relative to the sun.  The green curve is four years of actual data, and it it overlays almost perfectly.  As I’ve noted below, now with emphasis, PVWatts really and truly is a solar seer.


Solar Sister’s energy rank rises dramatically

My sister and her husband’s solar system was recently connected to the grid.  Their text message and embedded image nicely summarize what they think of their system:

Sister neighbor efficiency rank

              “Here is a great shot of our home energy report.  Thank you solar!”

An astronomical rise relative to their neighbors, from near the bottom to near the top.

When I received this image, I was reminded of a TED talk by Alex Laskey.  Laskey found that people are more highly motivated to save energy if they know how much energy they use relative to their neighbors.  Using human behavior to motivate energy conservation is a simple yet powerful idea.

And now that I see my Sister’s report, I wonder what motivated her and her husband to go solar:  the fact some of their neighbors also installed solar systems, my happiness with solar power, being able to make serious money by selling SRECs, or was it being ranked 98th out of 100 back in February???

Solar Sister

SisterIf you asked me a year ago whether my sister would get solar panels installed on her house, I would have said, “no way.”

It’s not that she ever claimed solar was bad or questioned its utility.  Instead, she struck me as being like many people, solar did not seem to be on her radar (although, I suppose solar wasn’t completely off her radar, given she had a brother who was very happy with his solar carport).

Things changed this past year.  As I understand, she and her husband noticed a few people in their neighborhood getting solar systems.  They also noticed SolarCity advertising everywhere, including malls and big box retailers like Home Depot.  Even my parents started wondering if solar was right for them.

While I don’t know what ultimately motivated them to do this, my sister and her husband contacted SolarCity as well as a local solar company to learn more.  People from these companies came to their house, they were given information and quotes, they got advice from me and they thought long and hard.  Then, earlier this week, I got an email from my sister.

She and her husband just decided to go solar!

They will be getting an 8.2 kW system, made up of 25 SunPower 327 modules.  That’s twice the size of my system.  They use more electricity that I do—for heating and cooling.  I was eyeing SunPower panels for our roof before deciding to build a solar carport.  SunPower panels are more efficient (they generate more power for a given roof area; which is great if you don’t have a large south facing roof) and SunPower panels look very nice.

My sister and husband were deciding between a solar lease with SolarCity, to buy a system outright from SolarCity (which they are now offering in some markets; provided you use their panels), or to go with a local installer.  They went with the local installer.

My main advice was to buy the system outright.  It is a lot of money upfront, but over the long run, you wind up making it all back, and then you get money for free until you move or die.  A solar lease doesn’t give you a steady income stream like buying a system does.

I know they will be happy.  And where they live, they can sell SRECs (solar renewable energy certificates).  I’m jealous about that.  With an 8.2 kW system, and the going rate of SRECs in their state, they will get over $1,500 back per year.

In addition, they will pay much less each month for their electricity bill.

The fact that my sister is going solar has made me realize two things.  1) That my sister and her husband are pioneers and 2) that solar will soon be common in many more states, not just CA (although I hope this momentum isn’t slowed when the federal tax credits expire in 2016).

It is amazing to hear that people in my sister’s community are talking about solar and getting photovoltaic systems.  I hear about solar power and other renewables almost every day in the news and on the radio.  This was not the case, even a year ago.  Solar power is here!

More accurately, solar power is everywhere, get some panels and you can use it too.  Free energy that doesn’t pollute.

Victory for solar power in NC, net metering rules upheld

Details can be found here:

This benefits homeowners who have solar or who want to go solar.  There will be no changes in the net metering cost rate for the next 15 years.

In other words, the rate that homeowners get for a kWh of electricity will remain equal to the rate that the Utility companies charge for a kWh of electricity.

Duke Energy tried unsuccessfully, and unfairly, to reduce this rate, as I described in an earlier post.

Solarize Carrboro

Solarize Carrboro

Spring is here and with it comes lots of sun.  For those of you who are considering solar power or want to learn more about it, check out the Solarize Carrboro website.

With the Solarize Carrboro discounts plus state and federal tax incentives, now is a great time to go solar.

They will hold a kick-off meeting April 2, 2014 at 7 pm at Carrboro Town Hall (301 W. Main Street, Carrboro, NC 27510).  At this kick-off meeting, the Solarize Carrboro team will step homeowners through the process, including solar equipment, tax incentives, installation, and financing.  Carrboro solar homeowners will also be on hand to answer questions.

See their website for details on how to RSVP for the event.

They’ve selected two installers–Southern Energy Management (the company that installed our Solar Carport) and Yes! Solar Solutions.

This is worth checking out.  And if you don’t live in Carrboro, check your local area for a Solarize program.  There is Solarize Durham; Solarize Raleigh, Solarize Mass (for MA), Solarize Seattle; to name just a few.

Contact the North Carolina Utilities Commission, to oppose changes to net metering

As mentioned below, net metering is under attack in NC.  I just got an email from Maria Kingery, CEO of Southern Energy Management (the company that installed our solar system), describing how to contact the NC Utilities Commission:

#1.  Write an email to the “Chief Clerk of the Commission.” Include “Docket E-100, Sub 83: Net Metering” as the subject.

  • Identify Yourself
  • In your letter, please let the  commission know who you are and why you decided to invest in solar.  YOUR story is important for them to hear and appreciate.
  • Tell the Utilities Commission: “I DO NOT support changes to net metering that will kill rooftop solar in North Carolina.
  • Ask the Utilities Commission to oppose changes to net metering!

#2.  Send your email to the Utilities Commission: or by U.S. mail to:    North Carolina Utilities Commission, 4325 Mail Service Center, Raleigh, NC 27699

I feel it is important to fight to keep net metering, to keep solar power strong in America.  I just sent off my email.

Solar Seer

A seer is someone who can predict the future.  In this case, the Solar Seer is PVWatts (, a program that calculates how much power a photovoltaic energy system will generate.  When I crunched the numbers back when our solar carport was commissioned, PVWatts predicted our system would generate slightly more power than we typically use in a year (106% more to be precise, see post below).

With 2013 over, I looked over the numbers.

Our solar carport generated 5,306 kWh (5.3 megawatt hr) in 2013.

This is 105% more power than we used in 2013 (we used 5,045 kWh).  PVWatts was thus dead on when it came to predicting power production.

So there are two take home messages:  1) By going solar, we’ve now eliminated our electricity footprint on this earth (at least with respect to our home electricity usage).  2) PVWatts is amazing.  Believe what it tells you.