CALGARY, ALBERTA--(Marketwired - Jun 6, 2013) - TransAlta Corporation ( TA.TO ) ( TAC ) today released their annual 2012 Report on Sustainability and announced that it is generating more electricity with less emissions and less overall environmental impact. "To be successful in the energy business, sustainability must be second-nature. Sustainability isn't merely a value or a belief - it's how we conduct our business," said TransAlta President and CEO Dawn Farrell. In 2012, TransAlta expanded its status as a Canadian renewable energy leader and it remains Canada's largest publicly traded generator and marketer of electricity and renewable power. TransAlta's renewable power generation capacity grew to 4.8 million MWh, making renewables 25% of its portfolio. Emissions also sharply declined in 2012. The report highlights a 33% reduction in kg of mercury emissions and a 36% (over 15 million tonnes CO 2 e) gross reduction in total greenhouse gas emissions since 2005.