District Energy

What is it?

District energy is a method used to provide a group of buildings with space heating, hot water, and air conditioning with a central unit that serves all of the buildings in the cluster. The process starts by producing steam or hot or chilled water at a central plant and then piping it underground to the separate structures. Since heat and air conditioning is produced at one location, individual buildings served by a district energy system do not need their own boilers or furnaces, chillers or air conditioners. District energy systems can increase energy efficiency, reduce unit operation and maintenance costs, increase reliability, and reduce life cycle and capital costs. Given that buildings using district energy do not need boilers or chillers, building owners and managers reduce their upfront capital requirements and reduce their operating, maintenance and labor costs significantly; this can allow for reduced financial risk and a higher return on investment. In addition, district energy systems have the flexibility to use a variety of fuel sources in larger, more economical volumes reducing the impact of supply and price variations.

Case Studies

Planning Community Energy
The International District Energy Association (IDEA) released a guidebook in June of 2012 - Community Energy: Planning, Development and Delivery aimed at helping elected officials, planners, real estate developers, and economic development officials who want to consider implementing district energy systems. The guidebook provides an overview of the local energy project development process, oriented to the U.S. market and intended to reflect relevant national energy and environmental policies and market conditions. (more information)

West Union, IA

The West Union Green Streetscape Pilot Program includes a geothermal district energy heating and cooling system which connects to properties in downtown West Union. (more information)

Arlington County, VA

Arlington adopted a Community Energy Plan in 2013, with district energy as a goal to be achieved. Progress on the district energy goal includes investigation and consideration of several suitable locations including Crystal City, Courthouse, and Rosslyn. Arlington County, together with the local gas utility and a real estate developer, engaged consultants Ever-Green Energy and Burns & McDonnell to investigate the viability of district energy in Crystal City, an urban neighborhood populated with office buildings and residential high-rises. So far the group has received positive responses from building owners regarding district energy in Crystal City. District energy is also being investigated for the reimagining of the Courthouse Square area, where the county is the main landholder. For Rosslyn, a high density and high energy use intensity area, plans are in place to create an Integrated Management Plan beginning in 2015. (more information)

St. Paul, MN

District Energy St. Paul provides heating to more than 80 percent and cooling to more than 60 percent of St. Paul’s central business district. District Energy St. Paul meets 70 percent of its customers' annual heating from a biomass Combined Heat and Power (CHP) plant fired by waste wood. It has reduced greenhouse gas emissions by over 200,000 tons per year, and reduced sulfur dioxide and particulate emissions by more than 60 percent. (more information)

Texas Medical Center

The Houston, Texas, Texas Medical Center, which has the world’s largest medical complex with 6,800 patient beds, uses Combined Heat and Power (CHP), and houses the largest campus district energy system in the United States. The system is projected to reduce carbon emissions by about 305,455 tons per year and save approximately $200 million in energy costs over the next 15 years. Additionally, the district energy/CHP system reduces dependency on the local electricity grid and provides supply redundancy for their critical needs. (more information)

University of Iowa ‐ Iowa City, IA

The University of Iowa fuels its district energy system with oat hulls (a by‐product of cereal‐making from the neighboring Quaker Oat facility) that are co‐fired with coal and natural gas. The system provides all the steam energy needed and about 20% of the total electricity needs for the University and hospital complex. Since the University of Iowa began using biomass in its on‐site power plant, carbon dioxide emissions have been reduced by over 50,000 tons each year. (more information)

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