This project will conduct a detailed techno-economic feasibility analysis for cost-effective, resilient, and robust retrofit of heating and cooling systems of co-located buildings using systems that are applicable for a wide range of Department of Defense (DoD) sites. The techno-economic analysis will compare the characteristics and performances of thermal energy networks with conventional legacy solutions for heating and cooling of around 20 buildings. From this comparison, developers will refine the most suitable technology option to advance for a potential later demonstration that serves two to five buildings. 

Other project objectives are to test the repeatability of a data-driven, sequential decision-making process that de-risks system integration and that leads to high reusability of technology solutions across DoD bases to accelerate current DoD rebuilding and modernization priorities.

The team will conduct a techno-economic feasibility analysis of replicable energy system solutions for heating, cooling and powering DoD buildings using Platform-Based Design, a data-driven, sequential decision-making process that de-risks system integration and leads to a high level of component reusability. In addition, the team will deliver a conceptual energy and control system design for a pilot site with quantified energy, power, resilience, and cost savings, and guidance for applying the framework to other DoD sites. The benefit of this process is three-fold. First, it compares thermal energy networks with decentralized, conventional energy systems using multi-objective optimization of performance metrics such as life-cycle costs and resilience, leading to cost-effective, reliable solutions. Second, it composes the thermal energy networks modularly to allow their expansion over time, thereby enabling phased investment and high customization to various other sites at low complexity. Third, it uses novel Modelica technologies to design and de-risk the energy systems implementation, thereby leading to robust system integration. The Modelica-based approach allows testing of actual control sequences, and export of models as digital twins to support implementation, commissioning and operation using open modeling standards and emerging ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) Standards 231P and 223P. This reduces the risks associated with deploying a system for which not much design and installation experience exists in the U.S.

Thermal energy networks have the potential to improve the resilience of DoD installations by allowing connected buildings to cooperate and share heating and cooling loads. This cooperation can increase mission resilience similar to the way electric microgrids have improved the resilience of electrical systems. DoD will obtain a comprehensive techno-economic feasibility study that compares various energy systems for heating, cooling, and powering buildings, including thermal energy networks. This rigorous process enables reusability of modular technology components and repeatability across installations, reducing technical risk and complexity, and allowing phased investment for scalable deployment. Lastly, guidance will be given for how to structure and finance such retrofits, creating a path toward retrofitting 20 bases per year with standardized systems. (Anticipated Project Completion - 2028)