ChissayLuke

Hi Ka Ora!
Interesting link!
I don't know how the US fuel prices compare with this units price and other installation costs, but if it really does have the 3-5 year payback they claim, it could be something!
All that California summer sun!

I spoke to some friends this afternoon who have such an installation and they were pretty lukewarm about both its productivity and cost savings though. We are in the Loire valley - maybe closer to the south it might be more impressive.

For sure anything we CAN get 'free' from the sun is welcome - as these technologies develop they will become more affordable, and in this light the differential between set-up costs in the future and ever-increasing fuel costs will only become more stark.
From my own research, I am not yet convinced that it is time to buy into such a system for domestic purpose yet.
Although (at considerable set-up cost!) my little solar powered storage batteries/invertors I described above now work nicely, but there I had no alternative.

Novocastrian

The amazon link isn't very informative. I'm just a simple chemist, can you explain the operating principle of these devices?

ChissayLuke

Does this help, Novocastrian?

http://www.solarwaterheaterpanels.in...or-vacuum.html

Ka Ora!

Magic of the universe

Novocastrian

Err, no. I'm not sure which language that writer is using, but it isn't one I understand.

I quote "Designed for the United States, the world’s leading technology innovation. Fairly simple Heat #2102 100′ Pipe Heat Cable. Constructed by lightweight, heavy-duty black polyolefin, today’s Solar Heating Systems feature state-of-the-art tube structure that creates a more robust surface area and this optimizes heat transfer for this sun’s energy for one’s pool. Dimensions with collector: 50 (W) x 79 (H). 4. Dimensions associated with collector: 50 (W) x 79 (H). ‘Going green’ is going to be trend nowadays because the world is facing large amounts of environmental difficulties specifically global warming. It’s an easy carry bag. Kilos created by collector: 130 lbs. SunChaser 16-Tube Solar Heated Water Collector Vacuum Tube.

, Even The entire Federal. Hook up nippy water to your inlet combined with sweltering water outlet within your existing amazing water line. 5. Easy Heat 100′ Deep freeze At no cost Connection is really a self regulating freeze shielding cable television comes from 100 feet, 300 feet, in addition to 500 the foot quantities. 2. The exact emissions contribute a whole lot to actually global warming the other method address this unique problem easy as by using solar energy with regards to homes. Dimensions connected with evacuated tubes: 58mm(OD) x 1800 mm (Length), about 2.3 x 72. Solar Water Heater for Swimming Pool. All the panels include the actual universal serial bus was needed to mount on roofs, racks or maybe ground. SunChaser 16-Tube Solar Great Water Collector Vacuum Tube. Weight regarding collector: 130 lbs. "

None the wiser. What does the vaccuum in the tubes do?

ChissayLuke

No idea....
I was just trying to help.
Try googling....

Novocastrian

And thanks for help.

Blackladder

Novo - nobody whose mother tongue is English concocted that; difficult to guess what the original language was tho' and I agree - pretty much unintelligble.
Blackie

Ka Ora!

Produces better energy collection and aids in the prevention of heat loss via conduction. As I understand it thermal heat does not pass through vacuum as it is not a conductive medium but radiant heat from the sun does.

Novocastrian

That much would seem to make sense, but if you think about it the black backing in contact with the water, is very close to 100% efficient in converting radiant flux to heat. Why have the tubes at all?

I'm obviously missing something, but there we are, I'm missing it.

Edit: OK I understand now, it's not the vacuum or the tube itself, but rather an AlN/Al coating (confusingly referred to in passing as AL-N-AL in both links above. What it does is extend the range of solar wavelengths efficiently used for thermal conversion.

http://www.btfsolar.com/specifications.htm

Another itch scratched.

Novocastrian

Now I've figured out how it functions, I think the crazy references to cable televisions were actually an attempt at conveying the idea of coaxial tubes.

Jesus wept.

ChissayLuke

Hey Novocastrian,
Whilst you are scratching itches, could you have a go at one of mine, please?
I understand the economics of my photo-voltaic cells, but not how they work.
The energy of the sun, converted into electrical energy.....
Could you very kindly explain, please?
Thank you.

Novocastrian

Glad to. The photovoltaic cell is basically a diode made of two layers of semiconductor material, usually silicon, one of which is doped with e.g. phosphorous (n-type or having an excess of electrons relative to plain silicon), the other is doped with e.g. boron (p-type or a deficiency of electrons usually referred to as "holes").

When the n-type layer absorbs solar photons, some electrons are excited from the valence band (the highest occupied molecular orbital, or HOMO) to the conduction band (LUMO. lowest unoccupied MO). The energy required to do this is called the band gap and for silicon it's a couple of volts.

Now if the layers are connected through an external circuit the non-equilibrium results in electrons flowing in the circuit to reach the p-layer. The flow of electrons is a current which can do work.

Simples.

ChissayLuke

Merci bien!

Novocastrian

De rien.

And next, The Larch.