Solar Powered Heat pumps?

[Joelad]

Curious to whether anybody has heard of solar powered heat pumps? Or anyone have any info on them?

[Tesla]

Hi Joelad
I worked for a company in NZ (for a short period) called Eco Systems. They had sold some but for reasons unknown they stopped selling the units. they were constructed from cu, a plate with tube in a serpentine pattern coated with black colour. Interested to read of any more solar heatpumps being marketed.

[paul_h]

Sanyo made some. But really the photoelectric process isn't good enough right now for such a high current drain, so the solar was just charging battery cells and it mainly ran on mains power IIRC.
Harnessing Solar heat and using absorption circulation (not using a motor for the compressor, but just a heat source like the old kero fridges) would be better, but then they aren't built small enough or cheap enough and have very unpleasant refrigerants.
A quick look at sanyo seems they don't do much with solar anymore, but that's just a quick look.
They do however do things like gas driven systems, which have a hot water system built in, or a generator to run and other stuff. CO2 systems, heat reclaim systems etc.

Seems even they've switched from the pointless expensive but not very useful yet photo electric driven systems, as that is still a pipe dream really. A solar panel set up to run a house with a small electrical demand costs 5-10K, and that would never run a large ducted a/c, you'd need triple that . So photo electric solar is a waste of time at the moment.
But it seems sanyo still target the eco market in different, more feasible ways.http://uk.sanyo.com/aircon/Products/

[Slugracing]

Their is one Australian company selling them now, I wont say who because they are rubbish ..

[desA]

Could a solar PV cell raise 250-450W?

[NoNickName]

Solar powered heat pumps work on either IORC (inverse organic rankine cycle), or absorption cycle.
Surely PV panels are not efficient enough to power a HP in a reasonable space.

[desA]

Surely PV panels are not efficient enough to power a HP in a reasonable space.

Can they can raise 250-450W of useful power? :)

[NoNickName]

Yes, they can, even more than that. The power is 60-150W per square meter in full sun, depending on type of cell.

[desA]

Yes, they can, even more than that. The power is 60-150W per square meter in full sun, depending on type of cell.

Excellent. Thanks for the info. :)

[mikeref]

Excellent. Thanks for the info. :)
Not far from me there is a building with a 10KW system. I think it has 58 solar pannels. Apparently, 10KW is the largest allowable for domestic purposes, in Australia. Spread over 3 phases, it feeds directly into the grid .;).. mike.

[desA]

Not far from me there is a building with a 10KW system. I think it has 58 solar pannels. Apparently, 10KW is the largest allowable for domestic purposes, in Australia. Spread over 3 phases, it feeds directly into the grid .;).. mike.

10kW of what? Evap capacity/refrigeration load? Or, compressor input power? Or, condenser delivery load? :)

10kW/105W = 10,000/105 = 96 panels @ 1m2 (range given earlier of 60-120W/m2.panel)
10,000/58 = 172 W/panel => average panel size 172/105 = 1.6 m2
Seems feasible... as 10kW compressor input...

[MikeHolm]

I Des, I don't know if you are still watching this thread. Anyway, PV (photovoltaic) systems are rated on the peak watts output of the panel, typically, at this point 150-300w (at 35-60vdc) each depending on the manfuacturer and they are joined in series until the output is somewhere between 240v and 350v DC then in parallel after that. They then go into the inverter to produce a stable 120, 208, 240VAC depending on your needs. The current will fluctuate with the solar radiation.

The panels are all rated at 25C cell temp and typically 800-1000w/m2 solar radiation. Here in Toronto we can get up to 1300w/m2 in full sun without much smog or on a clear winter day maybe 5-600w/m2. Typically we are lookng at about 16-17% of the sunlight being turned into electricity and research is increasing this by about .25% annually.

We always rate and buy a system by its peak watts output so if you see a 10kw system , as above, it would be made up of 40- 250w panels. The 10kw number is an arbitrary number to differentiate between a residential size system and a commercial size system which could run into the Mw sizes as power purchase rates generally decrease as sizes go up.

As far as using them for a refrig system directly, forget it. Yes there are DC compressors but they still suck up too much power. All off-grid PV systems store the electricity in deep cycle batteries and I have seen lots of DC household fridges working. That side of is it mature technology.

99% of systems are grid connected so running directly of the panels is not necessary except for some special technology such as cooling systems for medicine in remote regions etc.

[desA]

A belated thanks, Mike.