Dual Purpose – Heating & Cooling – Thermal Battery for Flexible and Energy-Efficient Heat Pump Systems

Summary

The project aims to develop and validate a 4-Ton (14.1 kW) dual-mode heat pump-thermal energy storage (HP-TES) system, targeting a ≥50% peak demand reduction for 2 hours, a ≥20% total energy efficiency improvement, and a cost of ≤$15/kWhthermal. Initial 5-ton system designs faced issues with battery weight (~1500 kg) and refrigerant charge (5x higher), leading to a revised 4-ton, 2-hour target with a ~800 kg battery. Laboratory testing demonstrated significant demand reductions: 0.6%-30% in cooling mode and 40%-60% in heating mode, particularly in extreme ambient conditions. The HP-TES transient model showed high accuracy, with capacity errors below 4% and power draw errors below 1%. An estimated incremental cost of $600-$700 per unit (8-12% of total hardware cost) is projected for commercialization, with simulated annual operating cost savings of 2% to 20% in Southern California.

Key Facts

Source Document

https://example-government.gov/policy-document-link