New York City Department of Environmental Protection
At a Glance
Commercial Energy Efficiency
Will Murtha investigated potential water savings that could result from energy savings in NYC buildings.
The New York City Department of Environmental Protection (DEP), which serves as the city’s water utility, enlisted the help of Will Murtha to help achieve its goal of reducing citywide water consumption five percent by 2020. This goal was set in anticipation of major repairs that will shut down an aqueduct for repairs in 2020. One of the strategies to ensure that the city has enough water during the shutdown is to manage demand through targeted conservation. While DEP had run successful programs to reduce water demand in wastewater treatment plants and bathroom fixtures, it had not yet investigated potential water savings that could be linked to energy savings in buildings.
Murtha and members of the DEP Demand Management and Resiliency team sketched out a summary of water and energy intensive processes in buildings and focused on HVAC-related heating and cooling and hot water heating as the best opportunities for combined energy and water savings. One of the challenges Murtha and the team encountered was that water is relatively cheap in New York City and is, thus, less rigorously tracked. Building projects focused on energy efficiency rarely calculated any associated water savings. Murtha navigated this challenge by taking advantage of a city local law that requires energy audits once per decade for buildings over 50,000 square feet. He obtained the data for the nearly 1,500 audits conducted in 2013 and whittled it down to a sampling of ten buildings that could serve as useful case studies for targeting future opportunities for combined energy and water savings in buildings.
Murtha found that many building energy managers in the city are missing an opportunity to make energy efficiency projects more financially attractive by incorporating potential water savings. Murtha provided a series of recommendations to the DEP that included increased water and energy submetering of cooling towers, boilers and domestic hot water heaters in order to draw more accurate correlations between water and energy in those processes and further strengthen the case for combined savings.