On Nov 1, 5:24*pm, Roger Chapman wrote:
On 31/10/2011 19:46, John Rumm wrote: On 31/10/2011 19:24, harry wrote:

Mind you, 0.21/Kwh would still give a better return than money in the
bank these days.
I wonder what percentage of the national load it provides on a sunny
day?
I have done 2747Kwh to date.

It hardly matters, it will need a proper power station sat there in hot
reserve anyway, so its real contribution is of little value.

Nonsense.

Unlike windmills the major contribution of PV panels is reducing demand
on the grid and with a multitude of individual houses any variation in
demand/output will be statistically easy to determine and any
variability will be small in relation to the other factors that the grid
has to take into account.

I don't know what the exact proportion is but even windmills don't need
100% of hot reserve. PV panels shouldn't need very much (or even any)
even if every house in the land was so equipped.

--
Roger Chapman

I think the small PV schemes are the way to go. There is a four volt
(approx) drop on my supply when a cloud passes (max-min). If it was a
huge array the effect would be greater. It depends on the size/
regulation of the local transformer too.
Small PV arrays reduce the size needed on th grid as electricity is
produced locally.
The main problem is that output is down in Winter.

I think that power generators will take into account sunlight
intensity and national cloud patterns to predict needs. They already
look at weather forecasts.