Public-Private Partnerships Result in Sustainable Energy Project at MMSD

摘要

Energy costs in the form of natural gas and electricity are a significant portion of the MilwaukeeMetropolitan Sewerage District’s (MMSD or District) operating budget. Through a unique set ofpublic-private partnerships, the District is implementing a project that utilizes landfill gas in lieuof natural gas. The landfill gas is used in turbines to generate electricity for plant purposes, andthe resultant waste heat is used to dry biosolids and create a commercially available fertilizerMilorganite?. The purchase price of the landfill gas is less than half the cost of natural gas,resulting in significant energy savings to the District and its customers. Further, the energysavings result in a net savings to the District, with consideration of the capital costs. However, itis difficult to quantify future savings, as there are factors (gas prices and landfill gas quantities)that are quite variable. In addition, the change in fuel results in a 95% reduction in District’sgreenhouse gases from stationary combustion sources. The public-private partnerships havetheir own set of challenges from contractual perspectives.