Monday, April 22, 2013

Here Comes The Sun -- A Post For Earth Day


It's an interesting feeling to be able to flip on a light switch, look outside and see the source of the power.

I suppose that would still be true if you lived within sight of Montgomery Burns' Springfield Nuclear Power Plant, or near a coal field. Neither happens to be the case here. I just look outside at the sun and think about the photovoltaic panels on the roof.

As with most things, the story of how those panels came to be there is somewhat roundabout. They weren't really what I was looking for, but what I found.

If you live in the Washington, D.C. area, or for that matter in lots of places in the East, you are undoubtedly familiar with power outages. Whether summer storms or winter storms, our utilities seem incapable of keeping the power on for everyone in nasty weather. Perhaps this had something to do with the deregulation of electric power by the state, after which the power company sold its power plants for almost $3 billion and cut maintenance and workers.

So when we here in D.C. learned a new word last summer, derecho, we learned how bad those cuts were. A derecho is like a stretched-out hurricane. While a hurricane is a rapidly spinning mass of air that moves along a path, the derecho is like a freight train moving through at the same hellacious speed. Hundreds of thousands of people lost power around here, including us. It wasn't the first time, but it got me thinking about how to compensate for when the power goes out.

There are outside gasoline generators, but those are really noisy and disruptive. The most elegant solution, I thought at the time, would be to have solar panels which not only generated electricity during sunny days but also could store it in a battery backup system. I knew some people who had solar panels, and knew they could cost upwards of $40,000, not an attractive option.

The more I looked into it, however, I found there was a newer business model emerging. Rather than buy photovoltaic (PV) panels, you lease them. The tradeoff is that they cost less than buying, but the leasing company, not you, gets the accompanying tax breaks. Some further looking, including on local message boards, led to Sungevity, a company based on Oakland. Seemed like a good alternative to putting up $40k or so.

After talking with a local representative of the company, we signed up. That was last June. We brought our panels online, finally, this March. There are many reasons for the delays. Sungevity uses local companies to do their work, and it took some time to get someone over to inspect our house to make sure it would support panels on the roof. We live in a split level, and the original plan called for one set of panels on the larger section, over the bedrooms. I asked what about the other part -- over the family room. Sungevity was thinking the same thing, so another set was added to the plan.

The permitting process is the most opaque to the customer. There are state permits and county permits and dealings with the local electrical utility to go through, and that all took months.

And there was the one thing I wanted, but couldn't get -- the backup system. Although I was told it's technically possible, and not that hard to do, Sungevity wouldn't authorize a battery backup to be attached to the system, which was originally the point of this endeavor.

It took some weeks to get an answer, and some pleading on my part, but it basically came down to the fact that Sungevity's financing arrangements with their suppliers don't allow anything to be connected to the system. One of their regional engineers told me as well that batteries aren't that well developed, need maintenance and can be expensive. He recommended a generator powered by natural gas, which our house uses for heating. We may yet do that, but Sungevity and its local installers are well aware that people back east are clamoring for the backup system. At some point, they and their finance people are going to have to rewrite the terms of their agreements to allow for the connections.

We decided to go ahead anyway, thinking that most of the benefits would come in the summer, when we use a lot of electricity for air conditioning.

Aside from that one issue of the backup, working with Sungevity was a great experience. The sales people answered our questions. The project manager was wonderfully responsive and the local company that did the install was professional and the crew knew their stuff.

Since we turned the system on in mid-March, we have monitored it closely. Sungevity provides a Web link so that we can look at the system production. I also asked for an external link so that others could see it as well. Apparently they used to have it, but the feature dropped out along the way. They should bring it back.

Looking at our electric bills from the past, we can see that we use about 30 kWh per day. So far, our highest production from the panels has been 47 kWh. The excess gets sold back to Pepco. We paid up front to lower our monthly leasing costs. It's hard to determine the exact payback time, due to the fluctuations of solar production.



In the meantime, we can track our power production on an hourly basis. You can see the difference between sunny days and cloudy days, even sunny parts of the day and cloudy or rainy parts of the day. So far, the system is doing great -- we have produced 986 kWh since we turned on the system. And, by the Sungevity site calculations, we have offset about 1,500 pounds of carbon emissions. That's not too shabby.

Solar has a bright future, pun intended. It's not hard to be part of it.












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