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.


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.

Net Metering under attack in NC. Duke Energy seeks to reduce payment for solar power by half

Duke Energy, North Carolina’s largest electric utility, just announced they are seeking to reduce payments for solar power from 11¢ / kWh to 5-7¢ / kWh.  Article here:

While this may seem like a minor issue, it isn’t.  This would have a devastating impact on the payback period for residential solar.  And it would make going solar uneconomical for residential customers.

For those not familiar with Net Metering:  when a solar system generates excess power, the house electric meter runs backwards and credits build up.  These credits are currently equal to the rate that consumers pay for electricity (about 11¢ / kWh).  So, when the sun is not shining, you get power from the electric company at the same rate.

Seems like a fair trade:  11¢ / kWh for power from the sun; 11¢ / kWh for power from the grid.

Duke Energy is greedy and wants to discount power from the sun as follows:  5-7¢ / kWh for power from the sun; 11¢ / kWh for power from the grid.

Does that seem fair?

Solar power doesn’t pollute.  Solar power is a renewable resource.  And contrary to what power companies say, solar power doesn’t tax or strain their power grid.  Excess solar power flows to your neighbors houses, providing power near its point of generation.

Visited by an ELF

The Organic Transit ELF

The Organic Transit ELF, parked under the solar carport.

A few months ago, a friend told me that he ordered a solar-powered tricycle (for adults) from a place in Durham, NC called Organic Transit. At first, I thought he was pulling my leg. Then I checked out their website ( and a bunch of You Tube videos.

I was impressed. It is called ELF. It has an electric motor, goes up to 20 mph, has 14+ miles of all-electric range and can be recharged by a flexible solar panel on the roof. It has pedals and is classified as a bicycle.

He picked up his wasabi-colored ELF earlier this week, drove it over and let me try it out. It is easy to drive and accelerates surprisingly fast when you switch on the electric motor. Bottom line, it’s amazing.

Here are a few more pictures of the ELF under the solar carport:


Note the solar panel on the roof of the ELF.

Note the solar panel on the roof.


First electric bill after solar installation

We just received our bill for the month of November:Nov2012 electricWe generated slightly more power than we used!  The extra 29 kWh will get carried over to December.  Given how much less solar energy we’ve been generating in December (because of reduced sunlight in Dec), we’ll definitely wind up using the credit.

When I received this bill, I was initially a bit perplexed.  I thought our bill would be $0, but instead it was $10.42.  Turns out Duke Energy (and probably all electric companies) charges a “Basic Facilities Charge” of $9.90 / month.  This charge has never been itemized on any of our bills.  Instead, this charge has been added to our monthly electric usage charge.  In essence, it has been hidden or “buried”.

This charge isn’t just levied on people with solar.  Everyone has to pay this monthly charge (if you don’t believe me, check out the rate schedule here:  We are on Residential Service, Energy Star.

Since I didn’t realize this charge was hidden in our monthly bill, I mis-calculated our monthly rate (I had been dividing the cost of the bill by kWh used; and got a rate averaging 12.8¢/kWh).  Turns out, from looking at this rate table, our rate is actually 9.3¢/kWh.

Let’s see what December brings in terms of power generation.  So far, it’s been overcast many more days than sunny.  And winter solstice is December 21.  Once the days increase in length, the power will pick up.