OLPC Human Power Generation Reality Check


The Department of Architecture and Design at the Museum of Modern Art is acquiring two XO laptops for their permanent collection because MOMA's Paul Galloway believes the design of the XO Laptop and the ideas it embodies belong in the museum's collection. While I'll not dispute his concept, I do think the display is in error.

XO laptop in the MOMA

If you look closely, you'll see that the display case has two XO laptops and a Potenco pull-cord generator. Personally, I don't think the MOMA should be showing off vaporware.

While XO laptop is in full-scale production, I even have one myself, no one has a Potenco yoyo, no matter the fancy Wired interviews. Individual purchase inquiries are rebuffed with this polite but vague brush off we've heard since last June:

We appreciate your interest in Potenco's human power generators. We'll be posting much more information about the product as we move into full scale production.
So I'm wondering when we'll actually see yoyo production. More than one Give One Get One donor was disappointed to find out that XO laptops currently don't ship with alternate energy sources, and children in the developing world should not be expected to have grid or generator electricity in the classroom.

Potenco is not alone in developing alternate human power generation, and it's not alone in lacking a production cycle either. Both the XOctoPlug and Freeplay Clamp Charger are innovative power supply ideas that are still in prototype mode. Emails to Freeplay on their Clamp Charger are returned with:

Thank you for your interest in Freeplay's charger for the OLPC XO. It is not currently available for individual sale, but when we have more information about availability, we will let you know.
Yet, unlike Potenco, Freeplay has a long and solid history of commercializing their products. May this mean we'll all have human power generation alternatives by this time next year.

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The Xoctoplug is amazing and it works, have used it myself. We need 30 of them yesterday in Nepal.

kudos to Carla Gomez Monroy and Josh Seal for inventing it

Freeplay's Scout and Lifeline are not available for individual purchase and I would suspect the XO table charger to fall into the same category.

That was one of my biggest disappointments with my OX. Every company I contacted that was 'supposed' to be making human powered or solar powered charges would not sell to me because I lived in America or because they did not sell to individuals. One of the reasons I loved the idea of the XO is becuase it was "green" that I could get off the grid with it. Why shouldn't Americans be able to buy an alternative powersource? It's good for the world if anyone gets off the grid.

OLPC was not very helpful in providing suggestions for other solar charges. Why recommend one that is not even in production yet?

It makes me wonder if Potenco and Freeplay weren't caught a little off-guard by the speed at which XOs went into production. Maybe they thought they'd have a bit more lead time before they had to get the human-powered chargers out there for users.

Either that, or they encountered unexpected issues, particularly if they were trying to produce the chargers AND come in under a predetermined price point.

Whatever the reason is for the delay, I hope they get chargers onto the market soon. Maybe they should do their own G1G1, if they're concerned about keeping the price down for users in developing countries. The XO users who took part in G1G1 have already shown a willingness to spend extra to support the OLPC mission in emerging markets. The obvious thing to do would be to appeal to those same people. BTW, if they make the yo-yo charger or the table crank charger able to charge things OTHER than the XO, watch them fly off the shelves in developed countries. That should get the price point down fast.

Putting a device into production is not a trivial process, particularly when you want it to have a long working life (Potenco says 5 years). In the video interview they say that testing is going on in Africa right now. That's great - and if it's effective the testing will reveal some design changes that must be done before production starts.

Also referencing the video and my previous commentary I note with approval that they are using a two-arm approach which raises the duty cycle above 50 percent. However, looking at the oscilloscope trace it's clear that there is no flywheel and the generator turns at the instantaneous speed of the pulley. You can see it ramping up and down with a triangular waveform as the user goes through his cycle. You're not going to get wonderful efficiency with that waveform, especially as it constantly returns to zero.

Also, note the speed at which the user moves his arms. I doubt that it's the most efficient speed - people familiar with exercise machinery should be able to confirm that the loading should be adjusted for a lower speed, allowing longer, slower strokes. The loading can be adjusted electrically within the parameters of the generator. People who want details may contact me by email - I have done some circuit development on this problem and it turns out to be a system problem.

In addition, while it's good that both arms are moving it would be better if both arms could exert force in both directions. The video shows the cord going slack on the return stroke. A continuous cord looped around the back of the user would provide a means to exert bidirectional force. Of course, the mechanical problems would be significant, since the cable would require a bearing and a rest through which the user could tension the cables by leaning back. But how can you solve a problem, I always say, if you don't have one?

Lastly, some thought should be given to methods through which the users, having exhausted their shoulder and pectoral muscles, could recline and use their legs to drive the system.

These ideas might both be acted upon, not by Potenco, but by suppliers of "aftermarket" add-ons. Or, to be more specific, by suppliers of critical components which would be needed by in-country manufacturers of such add-ons. This would include tooling for potential manufacturers of such components in industrializing countries as the massive demand for battery charging systems develops.

Don't expect that you could meet that demand by manufacturing here and shipping there. We should use comparative advantage to mutual advantage, and avoid production bottlenecks. With a five-year lifetime there will be an ongoing market that will keep everybody in the food chain working hard.

MOMA is about art. Sez so in the name. Art does not need to reflect reality, actually that's the whole point. So I guess they are totally OK to have the one and only pull-cord ever. For all I care they should attach the price tag of $100 to the XO to complete the "artistic" effect.


[For all I care they should attach the price tag of $100 to the XO to complete the "artistic" effect.]


Here is a very inexpensive source for solar panels for charging laptops. It is an NGO. Can power radios, TVs, computers, etc. Use to recharge batteries. http://biodesign.webeden.co.uk; Graham Knight [English & French] [email protected];

I'm sitting here a little north east of a pretty impressive storm bearing down on me.

Two of the local channels keep getting knocked off the air. This is when I realize the XOs potential. I have a weather radio (It IS tornado alley!) but I'm realizing I can _almost_ monitor visual radar from my xo if I lose power.

I need to be able to access internet with my router down. Being able to use my cell to access the net would do it, then a hand crank or yo-yo to power the XO.

Imagine the power to report on what's happening with the world and to monitor approaching danger if we could get the off-grid power and the internet/satelitte/cell hook ups to work. XOs could literally be lifesavers in natural disaster and civil emergencies.

I think I need to go hide in my bathtub now...

[[Lastly, some thought should be given to methods through which the users, having exhausted their shoulder and pectoral muscles, could recline and use their legs to drive the system.]]

How about a bicycle-pedal-like setup? I've seen mini-exercise devices that are basically just bicycle pedals on a little stand. They're touted as a way for a person to exercise their legs OR arms, as needed. They can be set up on the floor to exercise the legs, or on a tabletop to exercise the arms.

Powering a charger by this method would allow a person to use BOTH arms or BOTH legs. I would think that'd help reduce the amount of fatigue, compared to a cranking method that depended on only one of a person's arms doing the lion's share of the work.

I would love to invest in a Weza charger from Freeplay. That's the battery/charger combo that can be charged with a foot pedal/treadle. But OUCH, those devices are expensive. Even the lowest prices I've seen for it have been about $220, not including shipping. I wish a less costly version of the Weza was available. Maybe one of these days, there will be.

OR OLPC could actually release the I.D. and O.D. of the OLPC power plug and like the post to OLPC news some months ago about the poster's inability to get OLPC to tell him/her the specific polarity and voltage of of the OLPC's power brick output, if that was known this would be a non-issue. Once that was known the conversion from 12V- to whatever they need is a snap and then power generation becomes an exceptionally simple issue world wide.

"OR OLPC could actually release the I.D. and O.D. of the OLPC power plug"

You mean something like this?


Someone posted a link to it on this website a couple of months ago.

Rumor from Potemco is that the XO's new LiFePO3 batteries really want a trickle charge. The hand cranks, either as Yo-yo's or on a bench crank generate short, high amperage bursts of power. This means you want to store power for a while while you trickly out to one or more XOs. The usual solution for isolated areas, car batteries, is not environmentally friendly enough.

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