Ed Sirett wrote:
On Sun, 27 Jan 2008 13:13:49 +0000, The Natural Philosopher wrote:

David Hansen wrote:
On Sat, 26 Jan 2008 11:48:14 -0000 someone who may be "Pete Smith"
wrote this:-

I looked in to it for hot water, but it's of no use in the winter !
It's too cold!
What is too cold?
Te sky is too cold.

The exterior temperature? Solar panels work on the
sun, not the external temperature.


Exactly. Something that is in such short supply in winter, that peopl
need vitamin supplements..


In the winter it is highly likely not to be sunny enough to produce all
the hot water one needs. However, the heating that is provided means
less other fuels are needed.

On a bright winter day a well insulated house which has been warmed up
by the boiler can be maintained at a reasonable temperature by a solar
panel for the daylight hours. This does involve a heating system
designed for this.


On a sunny winters day, my room that has been warmed up by the boiler,
simply needs the curtrinsns drawing back to absorb far more sunlight
than a stupid panel on the roof.

In the summer you don't want scalding hot water.
Any properly designed solar system will have at least one thermostatic
mixing valve on the hot water system.

Why not use curtains?

Should it be necessary to control the store temperature there are a
variety of ways of doing this.

The solar panels charge huge batteries which power the inverters.
That rather depends on the system. You have described a solar only
island system. However, such systems generally have other means of
charging the battery as well. They also practice energy efficiency and
so tend to avoid electric fires.

A grid tied system has no battery. In effect it uses the grid as a big
battery.

Lord. All this cost an complexity and heavy use of energy to produce
less energy than the things took to make.

It reminds me of the 'we will never run out of oil' brigade. True, but
when it takes more energy to get it out of the ground than is released
by burning it, you do end up with some absurd economics.

Not something *you* would be bothered by, mind you.


True, the oil companies stop pumping long before that point is reached
because of all the other overheads. This means there is quite a lot of
reserves which are held back until the price of oil is sustainably high
enough. Therefore there will a longish transition period from oil to
other sources of energy, which currently are not worth the effort.



Longish in what terms?

a decade or two?