Hawaiʻi Energy Heat Pump Water Heater Capabilities Trial
- Written by Resource Innovations
- June 3, 2026
Overview
Resource Innovations (RI) is leading a program funded by Hawai’i Energy to bring energy efficient and grid-interactive heat pump water heaters (HPWHs) to hard-to-reach and indigenous communities in Hawai’i. The project’s goals are to verify and evaluate the energy performance and consumer perception of HPWHs in Hawaiʻi and to quantify the individual and aggregate load-shifting potential enabled by CTA-2045 controls. These controls allow utilities to communicate with water heaters and shift energy use to off-peak periods. The project also demonstrates a cost-effective pathway to combining energy efficiency rebates and demand response incentives to drive energy upgrades.
Program Snapshot
Solution
In Hawaiʻi, electric water heating accounts for about 70% of residential energy use on average. To address this, RI worked with Hawaiʻi Energy and community partners to recruit and enroll families in need of energy relief. Combined with load shifting, HPWHs can substantially decrease energy burden.
RI retrofitted aging electric resistance and solar-thermal water heaters with either Rheem or A.O. Smith commercial-grade HPWHs equipped with CTA-2045 compatible ports. This approach paired energy efficiency upgrades with advanced load shifting capability, creating a pathway to reduce household energy burden while demonstrating how HPWHs can serve as grid-interactive assets.
“This program has benefitted our family through significant monthly energy savings. RI managed this project in a manner that properly educated the participants on many aspects of energy use and how to save money, beyond what was achieved with a single appliance.”
Jolyn B
Results
The project established a field-tested pathway for deploying these systems in communities that are often underrepresented in clean energy programs. It validated the ability of CTA-2045–enabled HPWHs to function as flexible thermal storage assets. By preheating water ahead of peak periods and reducing operation during high-demand windows, the systems demonstrated how water heating load can be shifted to support grid operations while maintaining household service.
At scale, this approach gives utilities a way to capture multiple benefits from a single measure. HPWHs can reduce household energy use, lower customer bills, and provide aggregated load shifting capacity during peak periods. For utilities, this translates into a larger pool of flexible residential demand, improved peak management, stronger alignment between equity and grid modernization goals, and a repeatable framework for integrating energy efficiency and demand response into a single offering.
Overall, this positions HPWHs as a strong candidate for broader portfolio deployment, especially in markets where affordability, resilience, and grid flexibility are key priorities.
“We are so excited to work with Resource Innovations to support the deployment of grid-interactive heat pump water heaters in our communities. New to the efficiency portfolio, these smart devices will not only provide customers with energy bill savings but also help to inform future grid = flexibility programs in order to meet our clean energy and decarbonization goals.”
Caroline CarlDeputy Director, Hawaiian Electric
Take it with you.
Want to revisit these insights later? Get your own copy.