By George Harvey
When Amos Post founded Integrity Energy in Bethel, Vermont in 2011, he had worked for groSolar for nine years, gaining experience with solar photovoltaic (PV) systems. He soon brought John Mattern, also a veteran of groSolar, to work with him. There was more to their backgrounds than just their years of experience with solar installation, however. Post had already received NABCEP PV installation certification, and Mattern had fourteen years of experience as a carpenter.
While Integrity Energy focuses on PV installations, it does just about any sort of these a customer might wish for at a home or business in Vermont or New Hampshire. The company can install a system on a rooftop or on the ground. It has experience with grid-tied systems, both with and without backup, and with off-grid.
Post says opportunities to do off-grid systems do not come very often, but interest in such systems seems to be increasing, especially recently. He says people recognize the importance of resilience and see that they can be better prepared for power disruptions since solar costs are declining.
Integrity uses the components that are judged best for the job. This tends to mean Canadian Solar or SolarWorld modules. For charge controllers, Post uses OutBack and MidNite. For inverters, he uses SolarEdge, SMA, and Fronius for grid-tied systems, and Outback Power and Schneider for off-grid.
Post said customers who opt for systems with battery power should understand that battery lifetime depends very much on how the batteries are maintained. “A battery bank that is only used in a grid-outage and spends the rest of its life in float (trickle charge to maintain 100% state of charge) will last significantly longer than a battery that is cycled heavily daily or not maintained properly,” he said. “In general we tell people to expect 7 to 10 years from a well maintained and properly sized AGM bank and 10 to 15 years for a similar lead-acid bank.”
He elaborated, “People should know that it is a different lifestyle. People who are most successful living off-grid are very conscious of the energy they are using, and they know their systems – they have a good understanding of how the systems work. We tell our customers about batteries upfront, which is why we give them the two options of lead-acid and AGM. AGM needs nearly no maintenance. Lead acid batteries need to be checked regularly and refilled properly, and many people need to be educated about equalizing.”
Integrity Energy generally uses Rolls batteries for backup storage. The battery systems they have installed were mostly in a range from twenty to thirty kilowatt hours, though they have installed much larger ones.
When we asked Post specifically how he felt about using fossil fuel sources for backup, for instance a propane generator, he said, “The preference would be to harvest energy from renewable sources first and then use fossil fuels as a backup. With the evolution of PVs, battery technology, building efficiency measures and smart consumers, I’m hopeful that we will be able to drastically reduce the amount of outside sources of fuel that we need to use in the future.”
One of the more noteworthy of Integrity Energy’s installations was actually rather far out of our area, in Savannah, Georgia. It was an 87.5 kilowatt system with 307 SolarWorld 285-watt modules, Solaredge P300 Optimizers, and eight Solaredge nine-kilowatt inverters. In this case, the building, a multi-unit housing facility, was converting to LED lighting and air-sourced heat pumps.
Post takes pride in the ability to perform solar installations of high quality at reasonable prices and in his company’s polite and efficient ways of working. Integrity Energy’s website is http://ienergyvt.com/.
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