Energy investing - large Moat?

From The Age: Australian energy companies a monopoly ? Large Moat ? or just unfair pricing / profit gouging ( and we were told it was the Carbon Tax)  =? invest in Australain utility resellers or infrastructure companies?

http://www.theage.com.au/business/mining-and-resources/gas-industrys-depreciation-formula-a-licence-to-print-money-20140914-10gtrm.html