CO2 offset comparison between PV and fossil fuels

 I was wondering if anyone had any information regarding the CO2 offset
provided by photovoltaics compared to fossil fuels. I am after it in kWh or
any similar energy formate

Cheers.

  Paul wrote:

PV's don't produce CO2 so the question is more "how much CO2 is produced
burning fossil fuels to make the same amount of electrical energy as a
PV makes over it's lifespan (over and above the energy cost of it's
manufacture)."

This is a two part question. The first part is "How much energy can a
PV be expected to make over and above that used in it's manufacture?"
This has been studied, debated, argued and so forth endlessly. Since
there is a wide variety of technology and manufacturing steps involved
and since the use of the PV can vary, this is a hard number to pin down.

Generally speaking, most experts agree that PV's return anywhere from
7 to 30+ times the energy of their manufacturing. That is, if you have
panels that cost 1 kWh to produce then over their lifespans they can
reasonably be expected (depending on technology) to produce anywhere
from 7 kWh to 30+ kWh.

The second part of the question is "How much CO2 is produced to make
X kWh of electricity". This also isn't an easy one to pin down. Coal,
oil, natural gas and diesel plants all will produce different amounts
of CO2. You should be able to dig up an estimate somewhere though.

Obviously, while you can go pick a number out of a hat and say "So
man tons of CO2 not produced because of Solar PV!" it isn't really
going to be an accurate number by any stretch of the imagination.

Anthony