Connecting water, electricity and emissions in the Great Lakes Basin
In September 2008, researchers at Wayne State University were awarded a grant from the Great Lakes Protection Fund (GLPF) to develop software that will aid in reducing pollutant air emissions from energy used by water utilities. The project was being carried out in partnership with engineers from the University of Dayton, and the consulting companies Tucker, Young, Jackson, Tull, Inc., and Commonwealth Associates, Inc. This 2008 award was followed by a 2013 award from GLPF to commercialize a key technology that was developed pursuant to PEPSO (Pollutant Emission and Pump Station Optimization), LEEM (Locational Emissions Estimation Methodology). The LEEM venture escalated into a university start-up business, Energy Emissions Intelligence (E2i). Currently, the American Water Works Association (AWWA) is working with WSU, E2i and others to spread the use of PEPSO to water utilities throughout the Great Lakes region.
The team has designed a software program that is being used to model different water transmission and distribution operating scenarios. The software helps to understand how it may be possible to change the timing and distribution of pumping to take advantage of less polluting power sources, while still providing water pressure to meet variable daily demands. The project aims to answer whether pumping station optimization can cause a significant reduction in energy use and air emissions.
The software was developed and piloted with two water utilities in Southeast Michigan: the city of Monroe, and the Detroit Water and Sewerage Department (DWSD). DWSD is one of the largest water utilities in the nation, with annual water withdrawal of ~220 billion gallons and ~300M KW-hours of electricity consumed by high- and low-lift pumps annually.
First, the project team created an algorithm capable of estimating real-time emissions.
Next, PEPSO was created to incorporate this emissions algorithm with a hydraulic water distribution model. PEPSO performs optimization calculations for an entire water distribution system. PEPSO is being used to test many scenarios, such as water pumping with and without raised storage, or shifting pumping loads temporally and spatially.
The goal was to determine under which scenarios, if any, pump optimization can have a significant impact on emissions and/or energy use. By quantifying potential savings (both in total energy use and in emissions) that can be accrued by water utilities if PEPSO were implemented, we aimed to determine whether pump optimization is a useful, viable technology for water utilities. Finally, we aimed to make the finished optimization software and training materials available to researchers, policy makers, or water utilities to use. Much of this work is now completed, and forms the basis of the Water Utility Energy Challenge (WUEC).