At left: high-conductivity, shape-stable graphite + wax composite. Phase change composite photos, from top to bottom: ~100 micron SEM photo, ~2 cm sample, ~50 cm wide slab with machined grooves for tubing (middle section removed to show tubes). At right: dual-circuit phase-change composite heat exchanger integrates seamlessly with an air conditioner with minimal additional components. Compressor charges storage based on electric grid requirements, while pump discharges storage based on building’s cooling requirements. Photo credit: Said Al-Hallaj, NETenergy; Jason Woods, NREL.
Lead Performer: National Renewable Energy Laboratory – Golden, CO
-- NETenergy – Chicago, IL
-- International Copper Association – Washington, D.C.
-- Ingersoll-Rand – Dublin, Ireland
-- Emerson – St. Louis, MO
DOE Total Funding: $500,000
FY18 DOE Funding: $500,000
Cost Share: $500,000
Project Term: October 1, 2018 – September 30, 2020
Funding Type: Technology Commercialization Fund
The increase in on-site renewable energy generation for buildings has led to new requirements to maintain the electricity grid, which involves, in part, the addition of more flexible resources. The project aims to address this issue through the integration of a phase-change composite material with a vapor-compression air conditioner. This novel innovation has the potential to provide both demand response and energy efficiency by shaving and partially shifting the air-conditioning loads to targeted periods. Traditional thermal energy storage systems for cooling buildings, such as ice, are limited by low efficiency and slow response time due to low thermal conductivity. This hybrid technology will leverage the high conductivity phase-change thermal storage medium as a heat exchanger and also decouple the charging and discharging. These project advancements will de-risk the technology and bring the system closer to commercialization.
The project technology will serve as a flexible resource to shave or shift on-peak air-conditioning loads and dynamically charge or discharge in response to expected grid operating levels. The system will offer additional flexibility to the grid through increased energy efficiency and improved demand response. During the project term, the team will pave the path for commercialization by bringing in significant investment through an original equipment manufacturer (OEM) partner and applying off-the-shelf components such as compressors, fans, and pumps.
If successful, this technology has the potential to significantly reduce the utility costs associated with air conditioners by reducing both the kWh electricity charges and kW demand charges, compared to a standard vapor-compression air conditioner.
DOE Technology Manager: Antonio Bouza
Lead Performer: Jason Woods, National Renewable Energy Laboratory