ADS-B transmit power and range?

[poltergeisty]

I wasn't sure what forum to post this question to, but this seems appropriate. I have two questions:

1) What is the wattage used for transmitting ADS-B?

2) What is the range that ADS-B can be picked up? I'm thinking 200 miles or so. On a TCAS the range in the cockpit is 80 NM.