2025 Heat Pump Water Heater Baseline and Key Assumption Review

The Northwest Energy Efficiency Alliance (NEEA) contracted with Larson Energy Research to review key baseline assumptions and energy savings inputs for its Heat Pump Water Heater (HPWH) program. In 2025, NEEA updated key assumptions to better account for HPWH adoption in residential new construction, introducing new approaches to more accurately track savings across the region.

Based on the findings, Larson Energy Research recommends improving how NEEA estimates HPWH sales in new homes in Oregon and Washington, continuing to use existing retail sales data, and refining the natural market baseline to better reflect what would likely have occurred without NEEA’s intervention.