Simple solar thermal for developing countries

[AE-NMidlands]

I did similar experiments on ships in Africa and it was always surprising just how fast the water heated. Any way they get it to work is excellent modular too which opens it up to vertical stacking to increase pressure. Village power shower!

Surely you only need a higher header tank?
er, and isn't the sum more nearly vertically overhead nearer the equator? Or is the sun's movement round enough to heat your stack from the sides - with the benefit of de-rating it to stop it boiling at midday...
A

Thinking 2 birds with 1 stone, vol & pressure. I love the idea that this is traceable back to Billy the Kid and his black can shower. On the sun's relation to the vertical stack, surely it can't have much of an impact?

I agree high header tank = same (static?) pressure with no flow, but the extra coils of pipe = more flow resistance from friction, so not the output pressure you would expect.
Solar pv has different optimum angles at different latitudes, so why not this? if the sun is nearly overhead a lot of the day then won't the top of stack shade the rest?

[Joeboy]

Surely you only need a higher header tank?
er, and isn't the sum more nearly vertically overhead nearer the equator? Or is the sun's movement round enough to heat your stack from the sides - with the benefit of de-rating it to stop it boiling at midday...
A

Thinking 2 birds with 1 stone, vol & pressure. I love the idea that this is traceable back to Billy the Kid and his black can shower. On the sun's relation to the vertical stack, surely it can't have much of an impact?

I agree high header tank = same (static?) pressure with no flow, but the extra coils of pipe = more flow resistance from friction, so not the output pressure you would expect.
Solar pv has different optimum angles at different latitudes, so why not this? if the sun is nearly overhead a lot of the day then won't the top of stack shade the rest?

Only one way to find out, two tickets and one suitcase to Lagos! I think it's been thought out on the cone shape so max radial curve of pipe sees the sun at any one time even if overhead which tbh i dont remember in my years in the tropics. I do remember the speed of sunset to full darkness though. Almost an eyeblink.

[GarethC]

Proud to say I've met the founder (well, via a Zoom call). Really, really nice chap who had some useful advice for my own startup. I might point him to this thread so he can pick up any useful observations.

[Stan]

We all know that a black hosepipe lying in the sun will heat water, even in a UK summer. Decades ago, a very large UK company produced a double-walled hose designed to heat domestic water. The inner was black and the outer was transparent. The advert would show a huge coil resting on the roof where we are more accustomed to seeing rectangular solar devices. It did not look pretty but it does not come any simpler.