Show HN: PedalPC – Generate electricity and get exercise while you work
Hi HN,<p>The PedalPC is a computer desk with a built-in, pedal-powered generator.  It helps keep you fit by making useful, moderate physical activity an integral part of your workday.  It also provides you with a clean, reliable, and dependable off-grid source of electricity that you can set up anywhere.<p>I built it because I wanted some way to get exercise while I worked, but didn&#x27;t want the energy I expended go to waste.  I didn&#x27;t see anything on the market, so I built my own.  I&#x27;ve redesigned and rebuilt it several times over the years to arrive at what&#x27;s shown here.<p>I&#x27;ve been working on this as a side project since 2010.  I&#x27;d appreciate some feedback on it before developing it further.<p>The amount of electricity you can generate depends on your age, physical health, and how much you pedal each day.  I&#x27;m 58 and produce around 220-240 Whr a day pedaling 3-4 hours per day.  The PedalPC&#x27;s maximum designed power output is 100 W.  I typically generate about 60 W.<p>That may not sound like much, but it&#x27;s enough to power my computer, monitor, printer, desk lamp, and a cooling fan.  It also recharges our phones and battery-powered LED lights we use around our home for nighttime illumination.  It also powers our router and fiber network terminator to give us 24&#x2F;7 broadband internet and wifi.<p>The desk uses an e-bike direct-drive mini hub motor as the generator.  It&#x27;s driven by a toothed belt to minimize noise.  The generator charges a 12 V LiFePO4 battery to smooth out the generator&#x27;s variable output and store any excess energy generated for use when you&#x27;re not pedaling.<p>The desk has four 12 V DC power sockets and four pairs of USB power sockets.  You can view the power consumption of each power socket and turn each one on or off from a dashboard in your web browser.  Each 12 V socket also has PWM control, for varying things like cooling fan speed or beverage cup heater wattage.<p>The dashboard is served from a small web server built into the desk. You can use it to host any other content you want, like a blog, wiki, small Fediverse instance, etc.  (I use mine to host this project&#x27;s web site.)  You can also use it for a DNS server (e.g. pihole instance), file backup server, etc.  Of course, you&#x27;ll need to pedal enough each day to keep the server running!  My dream would be to develop a network of desks like this, with each user hosting and powering their own content.<p>I have built similar machines for two software developers in our town.  One was mostly identical to the one shown here, with a built-in desktop.  He uses it with his laptop.  The other was built without a desktop, so he could use it with his existing standing desk.  He uses his to charge batteries, power banks, and phones while he works.  Both seem quite happy with them.<p>Future plans are for a version made specifically for standing desks, better documentation, and an API to make it easier to integrate with things like Home Assistant, NextCloud, fitness loggers, or your own personal dashboard.<p>Would you like a desk like this?  (If so, please sign up for the newsletter in the footer on my site :) ).  If not, what would you like to see instead?  Any advice you may have is welcome.  Thanks.