Playpumps and Solarwind distilleries

Some solutions to the problems in life turn out to be simple, elegant and fun.

I don't remember when I first heard of the concept of the Playpump, but it stuck in my mind. I'm sure it was a podcast some time in the last two years. I was recently reminded of it when I looked at a video podcast called Wild Chronicles Digital Shorts. This is a National Geographic video site, formerly it was The Best of National Geographic Magazine, but they relaunched it some time back.

The Playpump is a device that they developed to solve the water problems in rural Africa. African people have problems with diseases from their water sources, as well as difficulty in getting retrieving the water, which often times has to be hand carried from local streams. Simply drilling a water well is sometimes not a sufficient solution because the water still has to be pumped out of the ground, and these places do not have electricity, or cannot afford electric pumps.

The play pump is a way to harness the energy of children playing on a merry go round to pump the water out of the ground. As the children push the merry go round around, it serves as the rotary motion to drive the pump, just like windmills used to here in the Midwest. The children's power is more reliable than wind, I suppose.

You can read more about the playpumps at http://www.playpumps.org

I used to think that I would like to buy a farm some day and take it completely off the power/utility grid. I used to fantasize about how to set up an array of windmills, solar panels, ponds, and biofuel plants in order to generate all the energy you would need, in addition to sustaining crops and livestock. The Playpump story made me think about one such device that would be nice to have if you didn't have a grid to connect to.

One of the cool ideas I saw a long time ago, at a K-State Open House, was a solar grill. This was a simple dish antenna, either coated with shiny material or made of a polished metal. Just like a magnifying glass has a focal point that you can concentrate and focus the sun's rays on, dish shaped materials reflect the sun into a focal point. The booth at the open house display had a small one that was cooking hotdogs to serve the visitors. This magnifying effect is also seen in the reflector of a flashlight and in satellite dish antennas. In the case of the flashlight, the light source is at the focal point, and makes a concentrated and directed beam. In the antenna's case, it is radio waves rather than sunlight that is being focused. This same principle is also used in a parabolic microphone, where you can concentrate sounds from far away and magnify them with a dish. You may have seen broadcast crews at football games with the clear plastic dishes with a microphone in the center.

I've always wondered why we couldn't make a water distillery from a solar dish. Instead of positioning a cooking grill at the hotspot, you would put a water coil. The water would boil off, and the pure steam could be cooled (by a heat exchanger using the incoming cool groundwater) and collected to make clean water. If you flowed the water past at a slower speed, you would simply have hot water. You could hook one of these up to a windmill or playpump, and you would have running hot water with no electricity (if it was sunny outside).

Developing such concepts and constructing the devices would not take a lot of money, but it would take some time. It would be great to get a team of college interns to try to develop the concept and come up with a quickly deployable and easily marketable system to try to sell to campgrounds, farmer's outbuildings, or any house on a well system. You could augment the playpump with a windmill driven pump, if that would work.

Like I said, some ideas are fun to work with.