Occam's Razor

Two months after starting our solar project, our solar panels are online and producing clean and free energy.

Installation day (June 16) was a big deal for us. It certainly was for our cat Cinnamon who was freaked out by all the noise and strange people inside our house and quickly ran under our bed for the duration. Direct Energy Solar sent four trucks with two guys to do the roof work and two to do the electrical work. The roof work required attaching rails to our roof to hold the panels. Before the panels were attached inverters were placed next to the rails. The inverters convert the direct current (DC) from the solar panels into alternating current (AC) used everywhere. Meanwhile two electricians crawled through our attic, laying cable. This required putting a hole in the roof to carry wires from the solar panels into the house. A hole was also needed on the side of our house so the cables could attach to the outdoor electrical junction box but also into the basement to our circuit breaker box. Only then did the crew on the roof haul up our twenty panels and put them in place, connecting them to the inverter box just underneath each panel.

It all went quite speedily, taking about six hours, one of which was spent waiting for the city electrical inspector to show up. However, having solar panels on the roof didn’t mean we could actually use them. Any attempt to do so would have caused a major problem, as we were not yet wired to put electricity back into the grid. So for a week the solar panels adorned our roof while we continued to draw power from the grid.

Wednesday found a man from the power company unexpectedly at our door. He came by to replace our meter. We needed one that would report power we contribute to the grid, i.e. one that would go backward. Happily this was simple to do: the old meter was unplugged and the new one plugged in. It took about five seconds, but it did shut off everything in the house. Still, I was reluctant to lift the switch that would start the flow of this green energy. I figured another inspection was needed first. Thursday night I finally heard from our project manager who said it was safe to turn the system on, which I did first thing Friday morning.

We’re not quite done. A building inspector still has to sign off on the project. In addition we are promised some tools. The Enphase inverters report on electricity produced but we need an account with them established so we can see real-time usage and get reports. We’ll have our own webpage and we can monitor our system in real-time anywhere in the world where there is Internet from the convenience of an app on our smartphones.

This time of year we are putting surplus energy back into the electrical grid. What we give back in electricity will count as credits during the darker months when days are shorter. If the engineers who planned our solar system are correct everything should even out. So unless we start adding power-hungry appliances we may never have to pay an electric bill again.

Of course nothing is free. Back in April when I first wrote about this venture, I detailed the costs. Our system cost $21,432.25. Subtracting healthy federal and state tax credits, our net cost is $14,002.58. With Solar Renewable Energy Certificate (SREC) income payable over ten years worth $9,262.50 the true net cost is $4742.08. In effect we are paying only 22% of the system’s cost.

How long would it take you to use $4742.08 in electricity from your power company? Electricity is expensive around here, averaging about 22c/kwh. This is actually good for justifying this investment. For us this is about 21,500 kwh which based on our projected usage suggests the system will pay for itself in four years. After that aside from minor maintenance that may be required, electricity should be free.

Once your system is up and running, it apparently fails to entertain. They tend to be very reliable and as they are solid state, so it’s rare for problems to occur. But I do plan to post updates from time to time, perhaps a year from now after we have some experience and metrics to look at.