Mother's Solar Tracking System

Image Gallery The housing for the light-activated phototransistor is cut out of sheet metal or aluminum and bent to shape.

Here's the long-awaited, low-cost answer to your solar equipment orientation problems!

A few issues ago-back in MOTHER NO. 52—we featured an ingenious low-cost solar furnace built by a fellow named Charles Curnutt out in Twenty-nine Palms, California. Not only was Mr. Curnutt's rig inexpensive (about $250) and (fairly) easy to build, but it offered just about unlimited possibilities. In fact, the furnace seemed capable of doing everything from heating water to powering a steam engine, and those applications didn't begin to tap its full potential!

But even better yet, Charles-the unselfish guy that he is-agreed to let MOTHER's research team use his design to build our own version of the solar tracking steam generator ... and to improve upon it if we could.

Well, folks, as many of you probably know, it's been a few months since that original article appeared in MOTHER ... but we've finally got our "interpretation" of Mr. Curnutt's design nearly completed (see MOTHER NO. 54, page 140). And—even though we still haven't found a steam engine that suits our needs exactly (this was one of the reasons for the delay in releasing our story)—we can say that the furnace itself is working quite well . .. well enough, in fact, to have powered a crude steam engine for an indefinite period of time.

FOLLOW THE SUN!

The secret, of course, to a really efficient solar collector is that it must track the sun ... that is, keep a dead aim right at ol' Sol as he moves across the sky. When this can be done, every bit of direct sunlight available is used to the fullest possible extent at any given time of day.

Basically, what MOTHER has done with Charlie's design is to mount 140 decorative wall mirrors onto a frame (with each 12- by 12-inch mirror attached to its own separate, adjustable—to-any-angle support), and then aim each of those mirrors at a roughly two-foot-square"steam generator" (boiler) ... which is housed in its own insulated box and mounted 10 feet above the frame on two sections of galvanized iron pipe. Not only does this pipe hold the "steam generator" system aloft, but it serves as a means for water to enter (and live steam to exit from) the boiler.

Additionally, the whole framework—which, remember, includes the mirrors and the "steam generator"—is free to move not only on a vertical axis (so it can "track" the sun on its journey across the sky), but also on a horizontal axis (so the "angle of attack" on the sun can be adjusted to compensate for changes of season). This horizontal adjustment is necessary, of course, because the winter sun is about 30' lower in the sky than the summer sun.