Water Use

The two-way connection between water and energy.

Water and energy are inseparable,  and that makes water efficiency one of the most overlooked energy opportunities in the country. Water supply and wastewater treatment are among the most energy-intensive services local governments provide, accounting for about 35% of municipal energy use. Nationwide, water and wastewater systems consume an estimated 50,000 GWh of electricity annually, costing more than $4 billion, and efficiency improvements could readily reduce that by 10% or more.

The relationship runs in both directions. Water requires enormous energy to source, treat, and deliver. Electricity generation requires water for steam, cooling, and other processes, meaning that water constraints directly affect energy reliability. In buildings, water heating is one of the largest household energy end uses. In agriculture and industry, water use and energy use are tightly coupled across many processes.

ACEEE examines water efficiency as an integral dimension of energy efficiency, exploring how policies and programs can reduce both together. Our research spans municipal water and wastewater systems, appliance standards, agricultural water use, and the water demands of industrial facilities. As climate change intensifies water stress across the country, addressing the water-energy nexus becomes not just an efficiency opportunity but a resilience imperative.