I have also noticed that the European sats have significantly higher power, however the solution to what is perceived to be a "problem" is NOT to increase the power. The power used on the CONUS sats is of course partly a financial decision related to the cost of the sats, and lifetime of the sats, etc, but I'm sure that a major consideration is to not use so much power as to interfer with adjacent sats. The CONUS sats are jammed together with 2 degree spacing for transponders on the same freq. If you look carefully at the European sats, it *appears* that they have spacing that is narrower than 2 degrees, but if you look at transponders related to services aimed at home viewers, I think you'll find that if you pick a transponder freq, then go to adjacent sats looking for that same freq, you generally won't find that same freq until you get out much wider than 2 deg. In the dozen or so examples I looked at, I didn't find any transponder on the same freq even going 7 deg away. I'm sure there are probably exceptions, but I really get the impression that in Europe, they seem to solve the interference problem by using a wider spectrum of freqs, while in North America, they tend to solve the problem via using lower power and bigger dishes that in Europe.
Also, one HUGE difference between the US services and the European services, is that the US has these incredibly restrictive rules prohibiting out of area reception of local network channels. Ie, instead of letting viewers subscribe to some satellite service with CBS, NBC, ABC, the government has given in to the networks, and prohibit sales of these network signals out of the area of the local channels. The end result is the waste of an incredible amount of satellite bandwidth, forcing the services to use more satellites, closer spacing, spend more money increasing the costs to everyone, and resulting in inferior quality to the viewers.
If congress would put an end to the local monopolies of network signals, allowing viewers to get network signals off satellite if they want to, you could get back to a situation where network signals took up only one transponder instead of all the transponders on multiple satellites.
I just think that it's an incredible waste of bandwidth to send exactly the same programming over literally hundreds of different channels. I am convinced that 95% of the power/spacing/bandwidth issues would dissappear immediately if congress would eliminate the local channel monopoly. I know that it is there to protect the local channels, however I really believe that they have gone to unreasonable lengths to protect these channels, and it is resulting in increased cost and lower quality to viewers.