Tuesday, October 25, 2011

AnafSolar presentation

AnafSolar's website, home page
25 Oct 2011: The Solar Power UK 2011 exhibition is in Birmingham and everybody solar seems to be coming. AnafSolar are an italian manufacturer of PV-Thermal panels and they invited the people they met at Ecobuild 2011 to come to a one day 'training course' in using PV-T.
   Being the first time they had presented in the UK, it was unclear whether it was a 'presentation of the concepts' or literally a 'training course' - we went with an open mind because we have read up on it beforehand and believe in the concept.
   I travelled there with David Hill of Carbon Legacy, and there were about 30 attending. Both David and I are convinced that this is a way of the future, if linked to thermal storage and GSHPs, and went determined to make this work.
   AnafSolar started in 1976 as a manufacturer of fire extinguishers and have a leading place in the Italian market for this. They fitted a large amount of PV panels on the factory roof to reduce their power consumption, and benefit from the sunshine of Pavia, Italy. They became aware that the PV panels could be 10% more efficient if cooled, and began to develop their own product using technology from the refrigeration industry.

A naf solar presentation, good product
The course was not well presented, and we only got the information when we asked good questions. However, the product sells itself to those of us who understand the technology, even if the company doesn't yet have well prepared presentations in english, with illustrations.
  A Danish guest said at one point "Let me say, that the principle benefit of PV-T has got to be in thermal storage in the ground", and that was music to my ears. I agree with him fully, you need a coolish thermal store to dump the heat into, not a hot water tank.

The idea of PV-T
PV (grey) is from a normal panel,
the thermal power (pink) is far greater on the same day.
 The heavy dotted line is showing the 10% PV power
increase in late morning and all afternoon
from the liquid cooling. 
The idea is that if a PV installation of 4kW can normally produce 3,300 kWh/yr, it would have 10% more power capture if cooled by liquid circulating during the summer months, producing perhaps 3,600-3,700 kWh in a year. That's great for the Feed in Tariff earnings. In addition, the thermal capture from such an array is about 2.5-3.0 times as much, if you have a means to store it. This is where thermal storage comes in. On my roof, I could expect to bury 7,000-8,000 kWh/year, providing the borehole with free heat, and this would be all the heat that the GSHP needs for the entire year for the entire house. the GSHP would still consume electricity, but would be working from such a warm medium that it would use even less than it does now.

  There are 'issues', such as pipe diameter into the panels, and conflict of aluminium and copper piping, but these can be met by good circuit design. There is also the requirement for smart switching and valving, as I have on my present system.
    The complexity for the installers attending is that one needs the 'Full Monty' to make it worth doing. Instead of doing PV one year, and then perhaps a solar thermal or GSHP another, the whole thing must be an integrated installation at the same time (to get the best results) - difficult to understand if you are not an expert on the entire range of technologies. Great for New-build, difficult for Retrofit.

The next direction
I had a chance to show the AnafSolar guys my research on the GSHP and Sunbox system here. What I would really like to do, is to take the PV panels off my house, replace them all with AnafSolar panels, tee them into my ground loop and monitor the result - compare with the existing sunbox.  This is the only house in the UK which is ready to go with all the infrastructure in place - the GSHP, the borehole, the plumbing system in the loft that goes directly to the borehole - and a researcher ready and willing to monitor every day the resulting energy flows.
   A major problem with this is that you can't legitimately sell on second hand PV panels. Apparently every panel is registered with OfGem, and they would show up again if installed elsewhere, disqualifying the owner from the FIT.
    The 22 180Watt panels could be used either on an off-grid installation, or I could talk to OfGem and explain that these have been taken off for research purposes to be replaced with the equivalent wattage, and would they kindly de-register the original panels. If I have the backing of my Professor, this might be possible.
  Thinking rationally, my PV roof is working so well that it's too good to disturb, so I will probably just add more panels to the South Wall. I am also considering a small house extension to the south, which could be roofed with AnafSolar panels.


  1. David,

    Just a comment - the cooling does not increase the efficiency of the pv by 10%, it actually has the potential to increase the power output by 10% (or energy yield). The actual efficiency of irradiance converted to electrical power is more like a 1.5% increase. (I suppose you could say that the efficiecny has a relative 10% increase against the standard efficiency)



  2. Hi Chris, i have rectified that, although the 10% is still the figure they quoted. Normal efficiency for them is about 15% conversion to electricity, so I suppose the 1.5% increase is 10%. This should produce more power over the year, although more effective in Italian heat than up here.


Comments will be moderated before showing. Please make them relevant to the subject of the posting. Comments which advertise commercial products will usually be deleted.

Popular Posts