🚀 go-pugleaf

In article <01bcc70c$bd572070$0400a8c0@BAHN>,
William L. Bahn <bahn@pcisys.net> wrote:
>
>
>Sheridan Mayo <scmayo@rsc.anu.edu.au> wrote in article
><604fsn$g6d$1@clarion.carno.net.au>...
>> The energy density of sunshine at the earths surface is 400W/square
>meter.
>> That's 400 MW per kilometer square. OK this is on a sunny day, but in
>Australia
>> 
><snip>
>
>I though the insolation was about 1kW/m^2.
>
>None-the-less, let's not forget a few things:
>(1) That rate falls off as the cosine of the latitude.
>(2) That rate falls off as the cosine of the sun's angle from zenith.
>(3) The insolation that reaches the surface falls off with theta due to
>greater atmospheric absorption and reflection.
>(4) A generating plant must produce electricity 24 hours a day.
>(5) Efficiencies of large area modules is significantly lower than single
>cells.
>(6) One square kilometer may not be a lot of land when it's mostly bare.
>But try to cover it with something and it's a very big hunk of real estate.
>
[snip lots of interesting stuff about practicalities and problems
of solar power.]

The value of 400W/meter square was actually for the UK so that
included a latitude factor but didn't include the other factors.
I was actually thinking about the idea of solar power in Australia but
didn't have any figures available.

Anyway I agree that there are problems & limitations with solar power
(chiefly that it is only there in the day!) but consider the practicalities
that were involved with nuclear power when it was first getting off the
ground. They were enormous and it was sheer political will (and the
defence connection) that made it happen. Look at the massive cost of
fusion experiements - yet they still go ahead. I think this really puts
the problems of solar power (which are largely down to
fabrication costs) in perspective. Solar power has possibilities but
by and large there isn't a fraction of the political will behind it.

For what it's worth I suspect that the future for solar power lies not
so much in large scale plants but in providing power on a small scale local
basis as it is much more scalable than other forms of power generation.
I did see something a while back about developing solar cell windows - 
i.e. they are largely transparent but absorb about 15% of the light for
power generation - the idea being that by covering a building in the
things it could generate some of it's own power (it was suggested this
be used for buildings like offices which are mostly used in the day).

Just some more thoughts

Sherry