By George Harvey
There are a lot of builders, and even a lot of solar installers, who have it a little easier because of the availability of grid power. Grid electricity often makes it possible to power tools and equipment without doing any more than running a cord to an outlet.
By contrast, building without any available electricity may require a bit of creativity. For any building that is off grid, the power has to be made available before it can be used.
Chris Milner, owner of Milhouse Enterprises, has had enough experience to have a standard approach to building without grid power. Simply put, you start with whatever it takes to put up the solar system, and power the rest of the construction with that.
A recent project in Milford, New Hampshire, is an example of his approach. And though Milner did not intend it, the example became a training ground for electric and building inspectors. There is nothing better than a well-planned and executed system to provide a benchmark for achievement, and this particular site was certainly that.
The property is at the top of a mountain. While such a site can be great for a view, bringing in electricity can be very much a problem. With slopes of 35 degrees and ledge rock almost at the surface for much of the way, installing utility poles was going to be expensive, and in this case, the home was to be a mile from the nearest utility line. The owner was looking at installation costs that might be as high as $100,000 just to get grid power.
Clearly, a solar system, in fact a great solar system, can be had for half of that amount. A friend who had put in such a system suggested that his installer, Milhouse Enterprises, had all the experience needed to provide such a system.
The fact is, this particular solar system had to be no less than great. The owner wanted eventually to be able to charge a Tesla with solar power. So the solar array and batteries had to provide all the household needs plus transportation.
First things have to come first, and this was a bootstrapping situation. Milner explained, “We try to get the solar in as quickly as possible, once the foundation is covered.” The initial building project was to be designed around getting the power to build the building. This meant that work started with a couple of gas-powered generators, horrible, noisy, polluting beasts that require fuel to be brought in. They provided the power for enough construction of the basement, foundation, building shell, and the south-facing half of the roof. Once that was done, it would be possible to install rooftop solar panels, the electric lines, and the batteries in the basement.
The photovoltaic system has 66 SolarWorld panels providing 18,810 watts. They provide power to 24 Deka Unigy two-volt batteries for a 48-volt system. The system has two Schneider inverters supplying 100 amps of standard household 120/240 volt service.
This was going smoothly with installation – Milner even got help from the building contractor moving 4,500 pounds of batteries – when the state electric inspector showed up and events took an unexpected turn. After looking everything over, he asked if he could bring in other inspectors to show them how a clean and well-organized off-grid solar system should look.
And so, Milhouse Enterprise’s master electricians became tour guides for groups of state and local inspectors. Many of the inspectors knew the code but had never seen an off-grid system so clearly laid out.
We would like to congratulate Chris Milner on work that is, literally, exemplary.