Wednesday, January 31, 2007

Watt-hour

I guess I'm (subliminally) posting this so that my wife will read it and turn off some lights. She loves her lights. :) Everybody knows when Jennifer is home; she has the house completely lit up. If she walked into a room 4 hours ago, you would know it because the light would still be on. I (on the other hand), go from room to room and turn lights off all day long. When I watch the kids or have the house to myself, you would never know that anybody is home. For example, right now I have the light on over my computer and that is it...

I heard the term "gigawatt" tonight and decided to figure out exactly how many watts a gigawatt would calculate to in household terms. If I had a gigawatt saved and was able to preserve that energy for a period of time, how long would I be able to "live" on it (taking into account tv, lights, radio, computer, vacuum, etc...)? Sounds silly, I know, but amuse me... Before I can calculate this, I need to see how many watt hours I'm using today. What is a watt-hour?

Watt-hour - Wikipedia, the free encyclopedia:
Power companies produce energy - a good - which is often purchased by the customer in units of kilowatt-hours. Consider a setup with two 50W light bulbs (100W total) left on for 10 hours per day. The setup will consume 1kilowatt-hour per day. If a power company charges US$0.10 / kilowatt-hour, then those two light bulbs will cost US$0.70 over the course of a week. (See unit juggling for more information.)
So a gigawatt would allow you to keep these two lights on for 10 hours a day for about 2,738 years. Or, in mathematical terms:

(1,000,000,000 watts /(100 watts * 10 hours))/365.25 days in a year = ~2,738 years

Realistically, I use more than 2 light bulbs. Let's assume that I pay about $120 for electric a month (which is kinda close). So in order to see how much time I could get from a gigawatt, I need to do more math...
$120 a month / 4.35 weeks = $27.60 a week
$27.60 a week / 7 days = $3.94 a day
$3.94 / $0.10 per kilowatt hour = 39.423 kilowatts a day

Now let's reverse the equation to find out how many years I can get on a gigawatt...

(1,000,000,000 watts / 39,423 watts a day) / 365.25 days in a year = 69.5 years

It would make sense to me that one day I might be able to purchase energy like this up front. Gigawatts, might be overkill, but who knows... We might have a higher demand for power in the years to come as well... We first need a device to store this energy. I would rather pay for power up front, than pay for it out the ass (play on words meaning after I use it). :) Allowing each home to store it's own energy would also solve the dreaded city-wide power outages (which just happened, last week).

No comments: