Solar powered ball mill

[mikeee]

If you had some clear plastic film in a "tube" form you could sleeve the outside of the black plastic pipe.

This would increase the amount of heat produced by the sun light heating the plastic and the clear

outer sleeve would trap the heat in the pipe and send it to your drying shed. Anytime you can put a

clear envelope over a dark surface you are increasing the thermal heat trapped inside the "envelope".

In one hour the sun applies enough energy into the earths atmosphere to run the planets energy needs

for an entire year. The trick is harvesting the free energy the sun gives us every day.

[MrB]

I'm not sure about how close you can get to those numbers, but the "official number" is 1000w / m2 on a sunny day from the commercial ones. But efficiency goes down, a lot, when the airflow is lowered. The air you get out is hotter, but the over all energy-output drops. I assume the same is true for home-built units as well, so if your going with a convection flow style you need a lot more m2 then you need with forced airflow, but since the air is to be used for drying stuff, rather then heating a living / recreational area, your going to want a higher temperature from the darn unit anyway.

Truth be told, i have no idea what sort of energy-output one should realistically expect. But it's a lot more then you put in to the fan, so it's still a win.

B!

[OldMarine]

Went up to the "shop" today just to see how my batteries were holding up with the fan and 4 led bulbs running. It's in the mid 30's and the inside temp is right at 60°. I could probably spray black primer on the south side of the fabric and achieve the same result but that would be no fun at all.

I ran the fan speed up and that corrugated pipe started reverberating and sounded like a giant tuba! My three-legged dog was hopping on two like a kangaroo trying to get away from it. It was a much needed belly laugh!