Some environmentally enlightened Wall Street heavy hitters stepped up to the plate last week to take a crack at reducing carbon dioxide emissions by buying out an ailing Texas-based utility, TXU. The company planned to build 11 new coal-fired power plants across Texas. The new investors, Kohlberg Kravis Roberts & Co. and Texas Pacific Group, say that after consulting with environmentalists they will scuttle plans for all but three of the proposed plants. The new company will make up for the prospective loss of future supply by encouraging customers to reduce demand through energy efficiency upgrades.