Solar pv

ashtreej

Hi
Do you still generate electricity on a over cast day if you have the feed in tarrif,Or has it got to be sunny.
Thank you

energysavingexp

ashtreej wrote: »

Hi
Do you still generate electricity on a over cast day if you have the feed in tarrif,Or has it got to be sunny.
Thank you

yes it still generates on clowdy and rainy days

rogerblack

energysavingexp wrote: »

yes it still generates on clowdy and rainy days

But very little compared to in summer.
For example, an installation 20 miles from me.
http://www.pvoutput.org/intraday.jsp?id=3744&sid=2940&dt=20110915&m=0
This is a nice sunny day in mid september.
Apart from half an hour around 10:30, and a few scattered clouds shortly after noon, the system was pretty much generating at capacity.
It output 20kWh.
Compare this with a couple of days afterwards.

http://www.pvoutput.org/intraday.jsp?id=3744&sid=2940&dt=20110917&m=0

The total generation on this day was around 4% that of only a couple of days before, with for most of the time the generated power being under a hundred watts (from a 3800W panel).

With the shorter winters days, it can get quite bad.
Over the UK, and many solar installations, the average looks like:
http://www.pvoutput.org/listteam.jsp?tid=110&t=m
(look at the green line)
You can see that in may it peaks, with a little more than 4kWh/kW of panel generated.
But by now, it's well under half that, and in December it's barely 10%, with the worst days being 5%.

reeac

I find that the output varies all the time as slight clouds pass over but the important thing is how many kWh the system generates per annum. Our 2.2 kWp system has exceeded its annual estimate of 1850 kWh. in the first 8 months [Feb.-Sept. inclusive] so either it's been a sunny year overall or else we have a sunny microclimate here.

keith_r59

reeac wrote: »

I find that the output varies all the time as slight clouds pass over but the important thing is how many kWh the system generates per annum. Our 2.2 kWp system has exceeded its annual estimate of 1850 kWh. in the first 8 months [Feb.-Sept. inclusive] so either it's been a sunny year overall or else we have a sunny microclimate here.

I think you will find that, a) due to the above average sunny weather and b) low installer estimates, most solar pv systems have surpassed their generation figures this year.

Let's hope it continues.