City of Sydney powers up rooftop trigen plant in effort to quit coal October 27, 2016 by Sophie Vorrath 2 Comments Town Hall House, Sydney - 20th October 2016. The City of Sydney will produce its own low-carbon energy for power, heating and cooling at Sydney Town Hall and its staff offices after Council approved a tender for a trigeneration plant in Town Hall House. Lord Mayor Clover Moore with Green Infrastructure Manager Chris Collins and Trigen project manager Bani Tachril. After years in the planning, City of Sydney’s 1.4MW rooftop trigeneration plant is in full swing, powering, heating and cooling Town Hall and Town Hall House.