[Greenbuilding] Fresnel lenses box solar cooker

RT archilogic at yahoo.ca
Mon Jun 3 14:23:07 CDT 2013


On Mon, 03 Jun 2013 12:51:27 -0400, Topher <topher at greenfret.com> wrote:

>> Also, I'm pretty sure that I remember my neighbour saying that CPV
>> systems are typically designed as tracking systems,

> tracking is /already/ more expensive than just
> adding more panels.

Is this true ?

You may recall that about a year ago I posted some messages to this list  
about the output from one of my neighbours' 10 kW single-axis tracking  
array.

He  was regularly getting up to 40% higher production than an  
identically-sized fixed array in the same neighbourhood. (I had posted a  
link to a site that provided real-time monitoring data for the fixed  
array).

My neighbour assured me that it would not have been more cost-effective  
for him to simply add more panels when I told him that I had doubts about  
the efficacy. I should probably mention that he's a thrifty Scot who would  
not spend an extra nickel (Canadian for the 5 cent piece just in case  
Murricans are unfamiliar) without first thoroughly exploring every  
opportunity to avoid the expenditure.

Thinking about it now, I suppose that the design of the tracking mechanism  
would be a factor in determining cost.

> The problem is not just the cost of the lenses.  In order to get the
> same output as a 20 meter^2 PV panel array, you need 20 meter^2 of
> Fresnel lenses; and some means of holding it very steady in the wind, a
> precise distance away from the collector; plus be able to move the whole
> unit (including the cooling system), very precisely throughout the day,
> every day.

I suspect that the above is not much of a challenge for the PV  
cowboys/gals these days judging by the number of 10 KW tracking arrays one  
sees mounted atop a single mast when out for a morning bike ride around  
this neighbourhood.

Even more alarming to me when seeing them is that more than a few (of the  
single mast-mounted 10 kW arrays) have been installed along the same  
wind-exposed ridge where I've seen barn roofs (ie cladding,purlins &  
rafters) hung up in the trees after a windstorm.




-- 
=== * ===
Rob Tom					AOD257
Kanata, Ontario, Canada

< A r c h i L o g i c  at  Y a h o o  dot  c a  >
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