On May 27, 2:06*pm, Martin Brown
wrote:
On 27/05/2012 12:57, geoff wrote:





In message
, harry
writes
On May 24, 11:42 pm, "the_constructor"
wrote:
House fitted with 4KW of solar panels

In brilliant sunshine, such as we have had over the past couple of days,
what prevents solar panels producing the full permitted 4KW. Down to 2KW
now.

A few days earlier, when not as hot, solar panels were producing 3.73KW.

Kindest regards,

Jim G

Though we have sunshine it is not "brilliant". To get the full
output, the sky need to be intensely blue,

Harry - do you understand what makes the sky blue?

And he is factually wrong to boot. To get absolutely maximum output from
a solar array requires a clear blue sky path to the sun and the largest
amount of thin white cirrus cloud everywhere else. Enough to scatter
light that was destined to hit somewhere else onto your PV.

White clouds are *brighter* than blue sky in every universe but Harry's.

If you have the option since mirrors are cheap and solar PV device
expensive a 120 degree mirror assembly \_/ either side of the active
cells gives you about twice the output (but not flat plate). Tends to
get the PV cells a bit too warm and makes clear epoxy go yellow though.



White clouds reflect sunlight back into space. So there is less light
underneath.
Albedo effect.
Even thin cirrus causes output to fall by around 10%.

Mirrors would be dodgy unless you could remove them in fine weather.
The panels could overheat. They are not designed for it.
And they would need constant adjustment.