The original paper may be hard to read, but the schematic tells all.

In a nutshell, radio guys noticed that sometimes when dealing with coax cable in large antennas occasionally you get a shock from the metal electrode. This is because the coax acts like a large capacitor and captures stray electrons.

These can be harnessed. 50 to 200 feet of coax is deployed in an antenna. Voltages get lethal above this so don't go above 200 feet. It's unknown as of yet if 4 loops of 50 feet is the same as 200 feet but it probably is. Do not let the exterior of the coax touch any (electrical) ground.

The charge builds up in the cable, and the metal electrode is connected to the top of a spark plug. The other end of the spark plug is connected to the center pole of an automotive coil. It turns out that coils work in both directions, that is in normal operation a cars system put 12V on the two terminals (+'ve and -'ve) on the sides and a whopping great huge spark comes out of the middle terminals.

But here we use the reverse - we connect the bottom of the spark plug to the center pole of the coil, and every now and again the spark plug fires, the current goes into the center pole of the coil and 12V comes out of the two terminals on the side which go into a battery.

Roger Walsh, who found this article, charged a 27 amp hour sealed lead acid battery in 3 days with this setup and reported that it works very well on wet or windy days and no so well on dry still days. It works better in winter than it does in summer.

In one sense this is better than solar or wind as there's nothing to buy, coax maybe, but usually this stuff can be scavenged or bought cheaply. Any spark plug and 12V coil will do. This is based on a design by Nikolai Tesla it turns out.

The photos of the buildings are a substation in Toronto built when Nikola Tesla designed and built the Niagara Falls hydro-electric generators which are still in use today. Tesla's would have spent some time in those buildings, still in use to this day.

Richard Sexton

I found it and transcribed the article:

Capacitive Battery Charger

What would you say if I told you it is possible to build an effective simple battery charger that has no moving parts, has no generator, works day or night, and has no solar cells? What if I told you this could be done with a few scrounged parts for which $10 would be an exorbitant price?

Just about every Ham operator knows better than to disconnect an antenna and then pick it up later by the connector and touch a ground. Enormous charges can build up on an insulated wire and the longer the wire the more charge that will build. Most all of us have learned to pick up the coax and tap or hold the antenna against the case of the radio to bleed off this charge. How few of us have ever been so poor as to have to think about how they can use this free energy. Wiley Almond, told me how to do this a few years ago. When he was a kid in the depression, buying batteries to listen to his homebrew 2 tube regen radio was out of the question. So they used the long wire antenna they had scrounged from an old telegraph line to charge the batteries so they could listen to the radio.

What Wiley did at the rip old age of 12 or 13 was hook a sparkplug to the end of the wire and then run the ground end (where the threads are) into a 12 volt coil off an old A model, but any old coil will do. The bottom connector of the coil that used to go to the points is hooked to the positive side of the battery. The negative side of the battery is hooked to a good earth ground and a 1 to 3 KV capacitor (a few picofarred type like those found in the horizontal section of a television chassis) is hooked from ground back to the wire where the top of the sparkplug is connected. That's it! Nothing should be touching ground except the ground post of the battery. Wiley was using about 200 feet of insulated wire and it will completely charge a 12 volt deep cycle every 2 or 3 days! A thousand feet of wire will do it a lot quicker but the voltages approach lethal levels.

What is behind this feat is that a very long wire acts like a capacitor and builds a charge on the wire. When a few thousand volts are reached, it will discharge by "sparking" across the sparkplug. The sparkplug delivers the charge to the coil that downconverts it to a few hundred volts and pulses the battery, kind of "squirting" a charge into it. The weather controls how much static electricity is in the air. Wind and super cold air seem to really make you think you can weld with this thing! I hooked a small neon bulb to a full wave loop on winter nigh when it was snowing with a high wind and the bulb burned continuously all night long! The higher you get the wire of the ground the better. The wire has to be completely insulated. It doesn't seem to make any difference whether you lay it out in a straight line or weave it back and forth. Length is the thing here, not size. Old phone wire, old coax from the cable company, anything that is insulated and long will do the job. I use my Ham radio antennas, as they are up and long already. This thing will weld the fillings in your teeth together if you are not careful with it!

Maybe next time I will tell you about the time I went by to see old Wiley, and asked his wife his whereabouts. She shook her head and replied that he was in his shop, listening to the radio by candlelight. She was not lying either! He was sitting in his shop with about 30 thermocouples he had made wired in series and formed into a circle with the centers in a tight circle on a homemade stand. Under the stand, in the center, was a kerosene lamp with the flame heating the thermocouples. 2 clip leads were hooked to a small transistor radio and he was enjoying the local country music station. He just winked at me and asked if I had ever enjoyed listening to the radio by candlelight.