This was submitted by Wayland Solar Coach Katrien Vander Straeten
The first Solar Tour in the Solarize Lincoln-Sudbury-Wayland program, last week Saturday, was a hit.
Around 30 people came to the Wolozin-Morrison house in Sudbury to get a closer look at a solar system that was installed by Astrum Solar in May (before the Solarize program kicked in) and has been running for three months now.
You may think the rooftop array — in this case, 24 panels — is the main event of a solar home tour, but there is a lot more going on behind the scenes.
Owner Bob Morrison took his guests into the basement to inspect the solar power meter, which is the entry point of the solar electricity into the house. It is from this meter, which keeps track of production, that he reads the monthly data to send to the MassCEC Production Tracking System (PTS). It is these numbers that allow him to claim his Solar Renewable Energy Credits (SRECs).
From there on the power goes into the house's main. What power is needed for consumption goes into the house, and what is overproduced is fed into the grid. This, too, is easy to monitor on the Nstar net-meter on the side of the house.
Morrison's meter was at that point spinning backwards, because more electricity was being produced than consumed. Net-metering allows the over-production flowing into the grid to be “deducted,” by spinning the meter backwards. At night, when more is consumed than produced, the meter spins forward again.
Astrum Solar only installs systems with Enphase micro-inverters. Each panel gets its own DC to AC power inverter, instead of one inverter for all of the panels strung together. In towns like Wayland, Lincoln and Sudbury, where shade often obstruct parts of even the best, solar-south oriented roof, this allows for a greater solar harvest.
Morrison's last gadget was the Enphase monitor, which shows each panel's production in real-time and makes that information almost instantly available on the internet. He even has an Enphase Android and iPhone app that allows him to check on the array at all times. And he checks it often, because he couldn't be more thrilled with the performance of his system.
“The system worked flawlessly from day one and has exceeded its expected performance. What has surprised me the most is how much energy is generated on mostly cloudy days,” he said. In the roughly three months that the 5.76 kW system has been running, it has produced 2,514 kW.
“Bob's experience with over-production is a common one among Astrum Solar customers,” says Astrum Solar Vice President of Marketing Michelle Waldgeir. “On average, our solar systems have been producing 14 percent more than our projections this year.”
So far, Astrum Solar has installed more than 100 kW in the three towns: two systems in Lincoln, three in Sudbury and seven in Wayland. Also, the was interconnected with the grid last week, and has begun harvesting solar power.
"It was great to talk with so many open house attendees, and hear the depth of their enthusiasm for residential solar power," said Lincoln Solar Coach Jennie Morris.
Anne Harris, Wayland assistant solar coach, added "I was happy to see folks at the tour who have already purchased a system through Solarize, as well as those considering one. It provided a nice information sharing opportunity for everyone."
If you couldn't make it, be sure to catch the next Solar Tour, which will take place on Saturday, Sept. 15, from 1 p.m.-3 pm, at 33 York Road in Wayland. The deadline to take advantage of the Soarlize Mass pricing is Sept. 30.
More information about the Solarize Massachusetts program can be found at www.solarizemass.com.