Demand Response Delivers for Greystar Apartments
- Written by Resource Innovations
- May 27, 2026
Overview
With a 100% clean energy goal by 2045, Hawai’i is increasing its reliance on wind, solar, and other energy sources. As renewable penetration increases, Hawaiian Electric is exploring innovative new ways to cost-effectively balance the grid, address resource intermittency, and engage customer-sited resources.
Program Snapshot
Solution
In 2020, Resource Innovations (RI) signed an agreement to incorporate its industry leading grid-interactive water heaters (GIWHs) into Hawaiian Electric’s grid services market. Since then, RI has been working to retrofit 3,000 electric water heaters with smart controllers across Oahu and Maui, transforming them into GIWHs.
These water heaters are aggregated and managed through a virtual power plant (VPP) software platform, enabling them to provide grid services to Hawaiian Electric. By automatically shifting when water heaters turn on or off, the system aligns energy use with periods of clean energy generation—without residents noticing any changes in their hot water service.
The project retrofitted electric water heaters in 1,216 apartments across three Greystar-managed buildings: Kapolei Lofts, Kalaeloa, and The Element.
Results
For each water heater connected to provide grid services, Hawaiian Electric provides a $3 monthly bill credit. Because these buildings are master-metered—meaning property management is responsible for paying the electric bill—the credits accrue directly to the buildings. As a result, the three properties receive $3,648 in bill credits each month, or $43,776 annually.
The program also delivers operational benefits for property managers. Automated maintenance alerts allow teams to remotely identify issues, such as burnt-out heating elements or leaks, and address them before residents experience cold water. Water heaters can also be remotely shut off in unoccupied units—such as those between tenants or during extended vacancies—to reduce unnecessary energy use.
In addition, the system collects and visualizes water, energy, and individual heater performance data, giving property managers insights to improve building operations. During installation, each water heater also receives a courtesy inspection of its thermostat and heating element. Together, these benefits help reduce operating costs, improve maintenance visibility, and support property managers’ ESG and clean energy goals.
Take it with you.
Want to revisit these insights later? Get your own copy.