8 cents a day

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main_p4400.jpgI'm now using my little moped to commute to work. It's about 5km each way so I have to recharge at work in order to get home. Luckily, there's a power outlet near the bike rack. Unfortunately with the little 1.5 amp charger I have, it takes about 6 hours to fully recharge so I'm stuck if I need to go back at lunch time.

I was curious how much juice it took to recharge my bike so I put my Kill-a-Watt on it while I charged it up overnight. The 36 volt SLA battery charger consumed 300 watt-hours (0.3 kWh) to bring me from pretty much zero to full charge.*

* The engine consumes 150 watt-hours for a full run but the batteries need 300 watt-hours to top up because of inefficiencies in charging / depleting.

At 12 cents a kilo-watt-hour in Connecticut, that's about 4 cents for a full charge, each way. Or about 8 cents a day.

Or $1.60 a month. Of which, I'm only paying 80 cents and mooching 80 cents off my workplace. Shhh.... don't tell anyone or they'll dock my salary!

Now, 20 days * 10 kilometers = 200 kilometers. At $1.60, that's about half a gallon of gas. If you did the equivalent in gas mileage, it'd be about..... 400 kilometers per gallon, 9.4 liters per 1000 km, or 250 miles per gallon equivalent.

I'm thinking of building a backyard wind-generator for my next project so hopefully I can get my daily rate even lower!

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This page contains a single entry by Karen Nakamura published on October 17, 2008 2:24 PM.

Karen 0 : Moped 1 -- ouch (NSFW) was the previous entry in this blog.

Brammo -- me wanteeee! is the next entry in this blog.

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