District Heating and Cooling Zones
Kyler Massner (author), Jonathan Rosenbloom & Christopher Duerksen (editors)INTRODUCTION
District heating and cooling systems, commonly called district energy systems (DES), provide heating and cooling to buildings that are connected to and powered by localized utility plants.[1] DES can meet the energy needs of a variety of community sizes in a cost efficient, renewable, and reliable manner.[2] DES is best suited in zones with a mix of medium to high density developments, such as college or government campuses, downtown districts, airports, mixed use residential clusters, industrial parks, and healthcare facilities.[3] DESs have been used since the late 1800’s, but local governments have increasingly turned to them to respond to volatile energy prices, the need for energy efficiency, concern for greenhouse gas (GHG) emissions, and a desire to increase resilience by decentralizing infrastructure and utilities.[4]
Despite DESs’ long history, barriers to their construction exist in many local development codes. Typically, community energy needs are considered late in the planning process and envision the use of a centralized energy utility. Local zoning ordinances may prohibit smaller scale generators from being constructed in particular zones explicitly or, more commonly, implicitly by not including them in permitted uses.[5] Local governments can remove these barriers by addressing energy infrastructure earlier in the development process to ensure that future developments are coordinated to leverage the benefits of DESs.[6] Additionally, local governments can expand opportunities for installation of small scale DESs by amending zoning ordinances to permit construction in residential and commercial zones.[7]
DESs typically have three core components: the thermal energy generating powerplant, the distribution system, and the energy transfer station.[8] The generating powerplant can be a traditional powerplant reliant on fossil fuels, a renewable energy system, or a combined heat and power system (CHP). The product produced is either steam, hot water, or chilled water, that is then pumped through a distribution system of heavily insulated pipes, providing heat, cooling, and/or hot water to buildings that are connected via a series of energy transfer stations (e.g., meters, valves, pumps).[9] The end product is distributed to connected buildings via energy transfer stations.[10] The three parts of a DES typically create a closed loop energy system (i.e. energy provided to the building is used and then returned to the powerplant for reuse), thus creating highly efficient systems that eliminate waste experienced with traditional energy systems.[11]
EFFECTS
DESs provide localized energy from diverse fuel sources, while building community resilience to future energy challenges.[12] Decentralizing power producing facilities to place them closer to populated areas reduces energy loss that escapes during the longer distribution distances typical of centralized utilities.[13] Additional benefits stemming from DESs include increased security from the volatile traditional energy market, increased system reliability, reduced maintenance and energy costs, and reduced GHG emissions.[14] The implementation of DESs also eliminates the need to house individual heating or cooling systems on the property. This frees space for other uses, including conservation, new projects, or improvements.[15]
DESs can stabilize and reduce energy costs by producing and storing thermal energy from sustainable resources at times of low demand.[16] Energy efficiency is increased by the elimination of distribution losses due to a closed loop energy system.[17] Because energy efficiency is improved, DESs can lead to lower utility bills, allowing a community to be economically competitive and attractive to start-up businesses and developers due to a reduction in operating costs.[18] In addition, reductions in utility bills make the district more affordable to low-income individuals and groups.[19]
DESs have flexibility in the type of fuel needed to operate the system. Relying on diverse fuel types insulates users from market fluctuations in a single energy source.[20] For example, as described below, St. Paul, Minnesota created a DES that integrates natural gas, fuel oil, CHP, and solar energy to replace a tradition coal fueled power plant. In doing so, St. Paul is able to stabilize pricing.[21]
EXAMPLES
St. Paul, MN
The City of St. Paul, working with the State of Minnesota, the U.S. Dep’t of Energy, and the local downtown business community, launched District Energy St. Paul in 1983 to build and operate a DES.[22] Codified in Section 405 of the St. Paul Code of Ordinances, the City granted a franchise to District Energy St. Paul, Inc. to operate a DES within St. Paul and sell the energy to residents of the City.[23] In return, the City receives fees from District Energy and regulates District Energy’s rates.[24]
District Energy St. Paul is considered one of the most notable DESs in part because its CHP system utilizes a variety of different fuels.[25] The ability to have flexible fuel options allows District Energy to maximize biomass utilization, save money, and reduce GHG emissions. For example, District Energy relies on recycled wood chips to provide the primary fuel for the CHP.[26] These wood chips are the product of urban wood residuals, such as tree trimmings and leftover construction material, that are delivered from sites within 60 miles of the plant.[27] Utilizing approximately 280,000 tons of urban wood residuals, District Energy’s CHP is able to produce 65 megawatts of heat and up to 33 megawatts of electricity that provides enough power for 20,000 homes.[28] Taking advantage of a renewable resource provides a stable energy supply, improved energy security, and reduced GHG emissions.[29] In October 28, 2015, District Energy announced that it had begun plans to eliminate the use of coal by 2021, a measure that would reduce CO2 emissions by 27%, the equivalent of removing 4,400 cars from the road.[30]
District Energy St. Paul was also the first in the U.S. to integrate solar thermal into the DES. By installing a 23,000 square foot system of 144 thermal solar collectors, primarily used for the St. Paul RiverCentre, the system can generate 1,000 MWh of energy each year and can export any extra energy produced to the grid.[31]
To view the provision, see Saint Paul, Minn., Code of Ordinances, App. F §§ 1,2, 5-6 (2007).
For more information on District Energy St. Paul practices see District Energy.
Schaumburg, IL
Schaumburg, IL explicitly encourages the safe, effective, and efficient development of DESs in its zoning code, permitting both commercial and residential construction of DESs in all village zoning districts. The only restriction which the City imposes is that the appearance be constructed with similar characteristics to the surrounding buildings. Schaumburg also reduces barriers by providing clear guidelines for construction of DES, allowing the network of conduit piping to be placed either within easements on a lot or within a vehicular right-of-way. Clear and specific development ordinances benefit developers by reducing ambiguity surrounding construction and are an example of how a preplanned and coordinated energy plan can lead to successful implementation.
To view the provision, see Schaumburg, IL, Code of Ordinances § 154.70 (C) (2018).
Detroit, MI
Detroit Thermal has reliably provided steam for heating, hot water, and absorption chilling to 30 million square feet of downtown Detroit for more than 100 years.[32] Detroit Thermal relies on Detroit Renewable Power as the primary source for its steam. DRP’s facility provides clean, efficient, and reliable steam by converting up to 3,300 tons of municipal solid waste per day into fuel to power large steam producing commercial boilers.[33] DRP’s waste-to-energy plant generates 68 megawatts of electricity with the ability to export up to 550,000 pounds per hour of steam.[34] Detroit’s system of renewable resource integration allows Detroit to reduces its waste volume by 90% and deliver thermal service from a clean, renewable energy source which reduces Detroit’s carbon footprint.
To view the provision, see Detroit, MI, Code of Ordinances § 6-509 (2018).
ADDITIONAL EXAMPLES
West Union, IA., Fayette County Comprehensive Smart Plan, West Union Section, 61 (2012); Jeff Geerts, West Union, Iowa: Small Town, Big Vision, District Energy 18 (2013) (local government using geothermal to fuel a district energy system).
Richmond, BC, Canada, Bylaws No. 8641 (2010) (establishing the Alexandra District Energy Utility to provide geothermal heating and cooling).
Seattle, WA, Enwave Seattle (providing district heating to customers as private utility).
Ball State University, Muncie, IN (geothermal district energy that has saved the university $2 million annually and has eliminated 85,000 tons of carbon dioxide, 240 tons of nitrogen oxide, 200 tons of particulate matter, 80 tons of carbon monoxide and 1,400 tons of sulfur dioxide).
ADDITIONAL RESOURCES
Informing, Connecting & Advancing the District Energy Industry, International District Energy Association, https://perma.cc/6MFC-G8RL (last visited June 13, 2018) (homepage for the International District Energy Association).
Combined Heat and Power Partnership, Catalog of CHP Technologies, EPA (Sept. 2017), https://perma.cc/A63W-HKA5 (last visited May 30, 2018) (contains an overview and a cost/benefit analysis of popular CHP technologies from the EPA).
Office of Sustainable Communities, District-Scale Energy Planning: Smart Growth Implementation Assistance to the City of San Francisco, EPA (June 2015) https://perma.cc/9HU5-AQ2F (last visited May 24, 2018) (providing a four-step implementation guide for district energy planning).
Lauren T. Cooper & Nicholas B. Rajkovich, An Evaluation of District Energy Systems in North America: Lessons Learned from Four Heating Dominated Cities in the U.S. and Canada, Lawrence Berkeley National Laboratory (Aug. 2012), https://perma.cc/97QY-7KU4 (last visited May 24, 2018) (North American district energy system case studies).
Creative Energy NES: Building Compatibility Design Guide, Creative Energy Vancouver Platforms Inc. 6-7 (October 2015), https://perma.cc/MDF2-FD4S (last visited May 30, 2018) (summarizing building design strategies for developers).
CITATIONS
[1] National Resource Council, District Heating and Cooling in the United States: Prospects and Issues, National Academies Press 7 (1985).
[2] U.S. Energy Information Administration, U.S. District Energy Services Market Characterization, DOE 4 (February 2018), https://perma.cc/HU4V-ZFH4 (last visited May 30, 2018).
[3] Id. at 16; Lauren T. Cooper & Nicholas B. Rajkovich, An Evaluation of District Energy Systems in North America: Lessons Learned from Four Heating Dominated Cities in the U.S. and Canada, Lawrence Berkeley National Laboratory 1-2 (Aug. 2012), https://perma.cc/97QY-7KU4.
[4] U.S. Energy Information Administration, supra note 2 at 19; Cooper & Rajkovich, supra note 2, at 1-2.
[5] Marlena Rogowska, District Energy Within the Planning Context: Exploring the Barriers and Opportunities for District Energy and Community Energy Solution in Ontario, Canada, Ryerson University 8-10 (2013), http://perma.cc/HKT4-NAXF (last visited June 5, 2018).
[6] Id.
[7] See id.
[8] Steve Tredinnick, Why is District Energy Not More Prevalent in the U.S.? Syska Hennessy Group (June 07, 2013), https://perma.cc/97PW-3PDZ (last visited May 25, 2018).
[9] U.S. Energy Information Administration, supra note 2, at 4.
[10] Creative Energy NES: Building Compatibility Design Guide, Creative Energy Vancouver Platforms Inc. 6-7 (October 2015), https://perma.cc/MDF2-FD4S (last visited May 30, 2018).
[11] Cooper & Rajkovich, supra note 3, at 2.
[12] Rogowska, supra note 5, at 6-7.
[13] Id. at 8.
[14] Office of Sustainable Communities, District-Scale Energy Planning: Smart Growth Implementation Assistance to the City of San Francisco, EPA 6-7 (June 2015) https://perma.cc/9HU5-AQ2F (last visited May 24, 2018).
[15] Id.
[16] Id.
[17] Id.
[18] Id.
[19] Id.
[20] Id.
[21] Id.; Ken Smith, The Wave – Spring 2014, District Energy St. Paul (April 2018), https://perma.cc/F7KR-77WU (last visited May 25, 2018).
[22] National Resource Council, supra note 1 at 13; Combined Heat and Power, District Energy St. Paul https://perma.cc/U3S5-XERT (last visited May 25, 2018); History, District Energy St. Paul, https://perma.cc/BHJ4-TWM6 (last visited May 25, 2018).
[23] Saint Paul, MN., Code of Ordinances, App. F §§ 1,2 (2007).
[24] Id. at § 5-6.
[25] History, supra note 21.
[26] Combined Heat and Power, supra note 21.
[27] Id.
[28] Id.
[29] Id.
[30] District Energy St. Paul Plans Elimination of Coal for Heating System, District Energy St. Paul (Oct. 28, 2015), https://perma.cc/T88G-QE6Q (last visited May 25, 2018).
[31] U.S. Energy Information Administration, supra note 2, at 54.
[32] Welcome to Detroit Thermal, Detroit Thermal (2018), https://perma.cc/3R8K-7Y49 (last visited May 30, 2018).
[33] Steam Energy from Renewable Sources, Detroit Renewable Power (2018), https://perma.cc/3HWH-KS8X (last visited May 29, 2018).
[34] Id.