Can I create the power for all of my mobile devices?

Electric_usage_in_kwhThis is another side project I’m thinking of. I’ve decided not to integrate WWAN into my UMPC (the last project under consideration) because I use too many devices to have a wireless data strategy tied to a single unit. I’ll like re-consider a 3G USB solution similar to the 3G PC Card approach I used a few years back.

So what’s the new project? Well, it comes from the serendipitous timing of getting back on my bicycle daily, reading Steve’s Solar UMPC blog and watching "An Inconvenient Truth" last night. The picture to the right is my actual household electricity consumption in kWh for the past 13 months. Back in March, we swapped out all of our incandescent bulbs for the highly efficient fluorescents in the house and you can see some of the impact. It’s now summertime here and we have to watch the central air settings or we’ll lose the gains we received from the new bulbs!

Since Barb and I both work from home, we likely have a higher electric usage pattern than most homes. Between all of the electronic gadgets, home theater equipment, video game consoles, and multiple computers that are always in use or charging, I’m starting to look for a way to offset my mobile device usage with an alternative means of energy. I’ve considered solar power in the past and actually used a small panel to charge my Windows Mobile devices for some time. However, I’m considering a human-powered solution for greater energy availability and simply for the exercise.

Ideally, I’d love to ride my bike for an hour a day or so regardless, so I’m starting to research bicycle powered power solutions that include a power inverter and a battery for energy storage. I’m not mechanically inclined, so it’s unlikely I’ll purchase plans and materials; if I go this route, I’ll opt for a pre-built solution like this one I’m considering.


I’m already riding my bike on a stationary trainer just like this during rainy days in the garage and this is a "drop and pedal" solution: just drop your bike on the trainer and go. There aren’t any modifications needed for my Trek 1500, so I can remove it from the trainer to hit the roads instantly. While I’ve never measured my riding output, I’m averaging around 18 mph for my one hour rides. Based on some limited research, I suspect I can generate between 150 and 200 watts in an hour on my trainer. Doing that five days a week could generate about 1 kWh or just a few kWh per month. When compared to my monthly bill, I certainly won’t be saving much money at all since the generated energy is a drop in the bucket for my overall household use.

But it’s not about the money. It’s about reducing my carbon footprint for all of the mobile devices I use. Storing that energy in a compatible 300 wHr battery could charge my iPhone, T-Mobile Dash, Samsung Q1P and even my MacBook Pro for at least a day of standard usage. Sounds silly if you’re just looking at the economics of it, but I think this would be an amazing statement: "All of the mobile devices I use are powered solely by energy I’ve created with negligible carbon-dioxide or pollution emissions." There would be SOME CO2 emissions since I do have to exhale. 😉

Anyway, just a thought for my next mobile tech project. The purchased solution of modified trainer and 300 wHr inverter and battery would set me back $684. Again, from a financial perspective, it’s cheaper to just buy the electricity from my local power company at $0.16 per kWh, which includes all charges such as generation, transmission, taxes and fees. Still, it’s quite the challenge and it’s under strong consideration.

I welcome thoughts, commentary and a check of my math here since I don’t have in-depth knowledge of this topic. I wouldn’t call myself a staunch environmentalist, but I am trying to do my share. We’ve sold one of our two cars, with the remaining car a Hybrid SUV, changed our home lights as I mentioned and try to plan our errands so that we hit multiple locations in one auto trip. If I can power my mobile devices solely with the power I create, that’s one more little step in the right direction.