Thursday, September 27, 2012

Looking Into The Solar

My father was a major penny saver and environmentalist, and decades before “going green” became watchwords for me, he did what he could to save money and respect nature. He was a biologist, and to him protecting the earth was a pretty important thing.

Dad would coast down hills in our 1961 VW beetle to increase his mpg and cook meals on the woodstove so we wouldn’t have to burn any natural gas. And don’t get me going on his flushing rules for the household of two adults and four kids.

I’ve always tried to economize, both to save money and to reduce my use of non-renewable energy. I think that every lamp in the house now has fluorescent or LED bulbs, I improvised a programmable thermostat in 1979 before you could buy one, and the family cars always got pretty good mileage.

My wife and I live part of the year on an old family farm in northeastern Pennsylvania, where we have a rural electric cooperative. For heat and cooking we burn expensive propane. Even though we sit atop the Marcellus Shale and wells are spewing natural gas everywhere around, there is none for us, as distribution lines just don’t make sense when the houses are a half-mile apart.

I had been thinking about generating our own electricity for some time. Since we’re in a hollow where the winds would not power a turbine, and hydro would drain the ponds pretty quickly, solar energy seemed like the best possibility. Our part of the country is far from uniformly sunny, but it’s not bad. We also have a barn with a roof oriented perfectly for solar cells (due south), and our trees cast very little shade on it.

Solar energy has gone through several iterations as photovoltaic cell efficiency has improved and as a new way of thinking about it took over. Instead of making electricity and storing it in batteries, an expensive and cumbersome task, the most common practice is to make the electricity and put it into the grid. This uses the grid as a gigantic battery, being charged with our power in the sunny daytime, then giving it back when the sun goes down.

With the help of the electric cooperative, we found a solar cell installer in Wilkes-Barre, Pa., about 50 miles south of our place near Hallstead. After having a visit by the salesman and then by an engineer, we decided to take the plunge. Our electric usage over the years has been quite modest, so we opted for a relatively small installation – 12 panels, each 3 by 6 feet and generating 250 watts, for a total output under high sun of 3 kilowatts.

Solar technology is cheaper than it used to be, but it’s still costly. Our project had an initial cost of about $16,000, but rebates and tax breaks will cut the price roughly in half. The panels are guaranteed for 25 years, and the payback period is about eight years.

The project took three energetic workers four days. First, they dug a trench between the house and the barn for the cables that would carry power back and forth. The panels themselves were mounted on racks installed on the barn roof. Each one has its own microinverter, which converts the DC power to AC so that it is compatible with the grid. The electricity flows from the panels and inverters into the main power distribution box in the house.

If we are using electricity in the house, which is most of the time, the solar power, supplemented by the grid, meets our needs. At night, the grid supplies it all. In the daytime when we are generating more than we are using, the power flows out of the house, through a “net meter” and then a pole-mounted transformer, where the 240 volts are stepped up to 7,200, and into the grid. It is likely that neighbors’ refrigerators up and down our dirt road are humming with some of the wattage coming from our barn roof.

It is a very neat installation, and my favorite sight is when the net meter literally runs backward and shows that we have put excess electricity into the grid. In the first week of operation, with a mix of sunny and overcast days, we produced about 10 more kilowatts than we used. This is not a huge amount, but little by little, we will be paid for it and come out ahead.

Photovoltaic generation of electricity is surely going to get better over time, especially with cells that make even better use of the sun. But it’s like having kids – if you wait for the perfect moment, it never comes. I would encourage people thinking about going solar to look seriously into it. It’s good for the environment, and an array of solar cells on the roof is a very cool sight.

Source: http://www.newsobserver.com/2012/09/16/2341691/looking-into-the-solar.html

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