Objective

Until recently, planners of public communities in the United States and globally have generally addressed the design and acquisition of energy systems for new facilities or major renovations without consideration of community-wide goals. These goals can be relating to energy sources, renewable energy generation, energy storage, or the need for future energy generation. In general, new construction and retrofits of public buildings typically do not address energy needs beyond those addressed in meeting minimum code requirements. It can consequently be difficult, if not impossible, to achieve community-level targets on a building-by-building basis.

Building-centric planning also falls short of delivering community-level resilience. For example, many building code requirements focus principally on increasing resilience by hardening buildings to withstand specific threats, but a multi-building community may contain only a few mission-critical buildings that require such hardening. Furthermore, hardening is only one aspect of resilience, and solutions such as recovery and adaptation should also be considered within resilience planning.

Best practices from around the world were collected through this project and summarized in a book of case studies. One clear takeaway these practices have demonstrated is that holistic energy master planning (EMP) can be a key activity in identifying cost-effective solutions for energy systems. Moreover, the EMP process can be applied to different scales of communities, e.g., to a group of buildings, a campus, a city, a region, or to an entire nation, making it more broadly applicable.

EMP is especially critical when working with community and campus-scale district energy systems that use a centralized plant for generating heating, cooling, and power, along with EMP making it easier to plan distribution of these utilities via networks to serve the aggregate heating, cooling, and power loads of multiple buildings.

The goal of this project was to develop guidelines and a supporting tool that aids in the planning of Net-Zero Energy Resilient Public Communities and then subsequently demonstrate the guidelines and tool at two Department of Defense (DoD) installations.

Technology Description

The U.S. Army Engineer Research and Development Center enhanced its EMP concept by augmenting it with the capability to perform a resiliency analysis of energy systems using an automated energy resilience of interacting networks (ERIN) tool that supports DoD energy policy. The EMP concept minimizes energy use at the building level, improves the efficiency of energy conversion and distribution, and uses energy from renewable sources to help achieve a net-zero fossil fuel energy status during normal operations. The tool analyzes if energy systems used for normal operations have sufficient resilience to support mission-critical operations during extended outages over a range of emergency scenarios, such as extreme weather, manmade events, or aging infrastructure. Additionally, the tool evaluates whether emergency technologies or enhanced energy systems will be required to meet energy resilience requirements. This project also developed a database of advanced energy system architectures and included their technical, economic and resiliency characteristics to inform the analysis of baseline systems compared to alternatives.

Demonstration Results

Based on these energy system architectures and an extensive technology database that includes prime movers, network distribution components, and auxiliary equipment needed in a system, researchers developed the ERIN tool as a part of this project. ERIN provides energy planners, energy engineers, system and building developers, political leaders, building owners, and city planners the information needed to better analyze and address their local energy circumstances.

The ERIN tool was developed to support the EMP process, which in turn supports resilience assessments of energy supply systems while under various threats. The tool simulates energy flows through a network of interacting district energy system components.

A cost assessment was developed for a study at Fort Leonard Wood, MO, which had a total of 17 mission-critical facilities and several thousand facilities listed as non-critical that are used for support functions. Of all energy resources currently used at Fort Leonard Wood, the top four consumption types were: heating consumption (42%), interior equipment (22%), cooling (13%), and interior lighting (11%). In 2020, Fort Leonard Wood consumed a total of 35,177 MWh of electricity and 797,695 MMBtu of natural gas. The study identified three building clusters and computed costs for each of them under several scenarios. The combination of the two largest building clusters had a cost savings of $2,297,696/year and a return on investment of 11.5 years.

Implementation Issues

The EMP and resiliency analysis processes require installation-specific energy goals, important constraints, community priorities, and requirements for energy system resilience. The project found it could be challenging to obtain such information because current mandates do not address individual building or building community energy goals, and do not stipulate specific requirements for energy systems resilience. During the course of this project, DoD did provide some clarification regarding the requirements for resilience, but a clearer interpretation of these requirements, especially as they relate to specific mission-critical functions, is still needed.

DoD services, U.S. Army Corps of Engineers, or Directorate of Public Works typically develop installation master plans in-house or subcontract this development to national laboratories or private sector companies. ERIN and system master planning (SMPL) tools can be used either by in-house personnel or by contractors. An interface for the SMPL tool developed through ESTCP project EW18-5291 (ESTCP 2018) and the U.S. Army project 633734 “Secure and resilient power generation in cold region environments” allows the use of this tool for a broader audience. That being said, all potential contractors involved in EMP will still require training on how to most effectively use the SMPL 2 planning tool.