Tuesday, May 6, 2008

Saving money with Solar Power

There has been a lot of talk about energy lately. Most recently I heard a story about the residents of Juno Alaska who had their electric bills increase by 500% this summer.

I have a solar panel cost about $300 in 2005, and the specialized purpose I bought it for no longer exists. Why not put it into service and take a chunk of my electric bill?

There are technical problems to overcome. I won't spend much time on that except to say that to use my solar panel I also need deep cycle batteries, a charge controller, an inverter and some wiring at a minimum. The cost of all these items together is in the neighborhood of $1,000.

The good news is that I just need buy some wire, I already have the other stuff. In fact, I'm thinking maybe I should by some more solar panels to go with the one I already have.

I dug out the electricity bill. On the last bill we spent about ten cents per kilowatt hour. A 100 watt light bulb burning for ten hours will use about a kilowatt hour. A computer in use might use the same or slightly more electricty than the 100 watt bulb. If its sleeping, My Dell only uses a small percentage of this.

An energy pig is writing this . Our household uses 23 kilowatt hours per day, last month we used about 800 kilowatt hours for a bill of about $80.

Now comes the fun part. How much will I save?

On a clear Minnesota day in the summer I think my solar cell will run for 8 hours producing 64 watts of electricity. In a day that amounts to about half a kilowatt of electricity generated by my solar cell or five cents savings per day. In twenty days I'll save a buck, in twenty thousand days this setup will generate enough power to pay for itself. By my calculations thats about 54 years.

If I ship my solar equipment to Juno, Alaska where power is temporarily at fifty cents per kilowatt hour it will generate twenty five cents of power per day -- in the summer.

Another way to look at it is that I need 46 solar cells like the one I have and some really big batteries to take care of my energy needs.

Here is what I think it would take to make solar cells economically interesting to me. Electricity costs similar to those in Juno this summer, solar panels at one quarter the cost they are today. If an aditional solar panel cost $75 and could save me twenty five cents a day it would pay itself back in about a year. Batteries are expensive, they require mainteneance and they wear out. Fuel cells would provide strorage using hydrogen allowing energy to be stored more efficently.

While I wait for these things to happen conservation seems to be the best course of action. In fact, it seems that the secret of living off the grid depends more on conservation than cool energy technology. The technology provides a certain amount of energy, but most of the savings comes from limmiting the use of power to start with.