http://www.satellitetoday.com/via/gl...tes_22875.html
http://www.esoa.net/Green-Satellites.htm

And from that first link...


Some argue that digital television transmitters produce significantly
greater carbon emissions than satellite television systems, because
satellites rely on solar power for most of their power and thus provide
a greener alternative to expensive terrestrial buildouts. A U.K. trade
group, €œUK Space,€� estimated in 2006 that just the 50 most powerful
analog television transmitters in that country (out of a total of 1,400)
required 54 megawatts of electricity, representing a quarter of a
million tons of CO2 per year that could be replaced by satellites that
essentially use no terrestrial electricity at all.


55 analogue Tx's requiring 54 megawatts?..

Don't quite think so...

Probably isn't far off..each transmitter has several; 100KW units,

Don't think Pye TVT or Marconi ever made more than a 40 kW one at most
and those that were .. were very few and far between usually for the USA
market..


and
they aren't 100% efficient.

Remember or did you see that article on the Sudbury transmitter recently
when it was a 250 kW ERP analogue one. Two 6.25 kW transmitters used?..

Around 50% efficient but not on the go flat out all the time .. Course
the digital ones, valve engined are even more efficient...


Of course the energy over say 25 years of a satellites lifetime has to
be compared with the energy to put the satellites up in the first place...

And put in the context of the UK population as a whole. where it
represents less than a watt per person.

So just turn the lights off, watch Sky, and save the planet.



And do switch off your Sky box, those on standby do add together for
quite a lot of power..


--
Tony Sayer