FWIW, PJM margin varies by tier...6 to 13K for non-members trading the JM on NYMEX. The contract is based on 2.5 mega watts times the delivery rate of 16 hours times the peak days in a month, which varies between 19-23 days. The only 19 peak day this year will be Nov'08. 19 peak day tick size per contract is $38 bones and up to $46 on a 23 peak day month. A nickel a megawatt. Prebon and Zone Energy service smaller traders along with the ususal suspects like Man, Refco. ABN is also committed to the sector. This beast gaps, it is like trading a real thin stock like Allegany (Y), 5 points is common between trades. A couple of hundred bones +/- per contract per day is a range one could expect to see. Trading 3-5 contracts is a good business. You can see the ISO expected peak usage load graph depending on the grid, for example in California http://www.caiso.com/outlook/SystemStatus.html
On the Ice today the range was about $34 . 800 MW per contract for a grand total of $27.2k . This thing can put you in your place real fast thats for sure.. I trade a product similar to JD, not JM.
LOL, I actually know someone who actually tried to trade them from Enron. The spread you guys gave was so insane that it made absolutely no sense even if the guy was to be on the right side. Suffice to say, I was not too surprised at his story.