On Monday, 19 August 2019 20:03:05 UTC+1, Chris Green wrote:
I know only too well that a (for example) 250 watt solar panel doesn't
produce a continuous 250 watts for 24 hours a day every day of the
year. There's those things call nights, not to mention dull winter
days, and even dull summer days.

I've searched diligently but I can't find a site providing what seem
to be realistic 'ball park' figures for UK regions. I suspect there's
a special word for this percentage which I haven't found.

So, can someone either provide a figure for the average output of
(say) a 250 watt panel over the year in eastern England or point me at
a site that will tell me this. (I seem to remember the figure is
something like 20 to 25 percent, so I'll get an average of 60 watts or
so from a 250 watt panel).

--
Chris Green
·

My 4Kw roof array does 4000Kwh/year approx. (W. Midlands.)
It has an almost perfect orientation, open aspect and no shading.

Weather has an effect. hrs of sunshine, air temp, etc.
They reckon to deteriorate 1%/year.
Newer ones do better I'm told as the technology has improved.