Tuesday, November 4, 2008

Going Solar in Howard County: Battery Backup

If you've ever thought of using solar power, Howard County offers one of the best deals in the U.S., and tax breaks make early 2009 a great time to do it. I'm going to do several posts about it.

One of the coolest unexpected features of solar power for our home is the battery backup option. I didn't know anything about it when I got started, but for us it's proven to be one of the most gratifying aspects of the whole system.

Our home in western Howard County is on well and septic, which means if the power goes out, it can get real inconvenient real fast. Thunderstorms, wind and construction all seem to have an effect on our power supply from BGE. Actual outages have been fairly rare, thank goodness, but we get fluctuations and spikes that can get mighty annoying.

When we built our home, I considered putting in a gas generator, but was never comfortable with the cost or maintenance. I did get the home wired for a portable generator, though, which meant running selected circuits to a separate panel in the basement. I just never got the generator and fortunately the power has not gone out for more than a few hours at a time.

Under normal circumstances, all you need for a solar installation are the panels on the roof and an inverter that changes the solar direct current into alternating current for your home. The AC power feeds directly into your existing home circuitry. If it happens that you generate more electricity from your panels than you are using at any moment in your home, the excess power feeds back into the neighborhood electrical grid and your electric meter actually spins backward (a very cool thing to see).

As an option, you can add a battery backup system that can store several kilowatts of power to drive critical circuits in your home. We got a small one that stores 5 Kw and cost around $6K. The battery backup option does not qualify for the solar tax credits or incentives, but it has proven to be a very worthwhile investment for us.

The great thing is the battery is totally silent, maintenance free, and kicks on within milliseconds. Now, when we have power spikes and hits, the circuits that are on battery backup operate without a hitch. My wife can be watching TV in the bedroom and not even know that something happened. Likewise, our water pump, refrigerator and freezer operate without interruption.

We haven't had an outage of more than a few hours, well within the capacity of the battery. But if we did, the system would be able to recharge at least partially whenever the sun comes out, and continue doing so indefinitely. I'm hoping never to have to go and get that portable generator, or the gasoline and noise that go with it.

See the other posts in this series:
Going Solar in Howard County - My Experience
Going Solar in Howard County - Taxes and Incentives

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