- By:
- Gao, Zhiming ; Zoldak, Philip; Balogh, Dan
- Page Number:
- 79-88
- Book Title:
- 11th Thermal and Fluids Engineering Conference (TFEC) Proceedings
- Publication Date:
- April 21, 2026
- Publisher Location:
- BEGELL HOUSE Inc., United States of America
- Conference Name:
- 11th Thermal and Fluids Engineering Conference (TFEC)
- Conference Location:
- Arizona State University, Arizona, United States of America
- Conference Sponsor:
- The American Society of Thermal and Fluids Engineers (ASTFE)
- View DOI Listing:
- https://doi.org/10.1615/TFEC2026.cbf.061646
Abstract
U.S. buildings account for approximately 40% of total U.S. energy consumption and 75% of electricity use, emphasizing the need for efficient, resilient, and secure energy solutions. Micro-combined heat and power (micro-CHP) systems provide an effective approach by simultaneously generating electricity and recovering waste heat for thermal use. However, current commercial micro-CHPs face challenges in achieving higher efficiency, lower emissions, and reduced cost. To address these limitations, a novel micro-CHP prototype powered by a unique opposed-piston four-stroke (OP4S) engine was developed. The OP4S features a simplified, low-cost design with reduced heat losses and dual-piston operation that enables higher thermal efficiency. Experimental results demonstrated up to 35.2% AC electrical efficiency under lean combustion, surpassing the best-performing ICE-based micro-CHPs reported publicly. In addition, the micro-CHP enables a total CHP efficiency exceeding 93%. The prototype operates reliably for over 600 hours, providing flexible and efficient thermal and electrical outputs. This novel OP4S-based micro-CHP offers a resilient, low-cost, and energy-efficient solution suitable for residential, light commercial, and remote community applications across diverse climate zones.
