Demand Response Performance of GE Hybrid Heat Pump Water Heater.

摘要

Increasing penetration of heat pump water heaters (HPWHs) in the residential sector will offer an important opportunity for energy savings, with a theoretical energy savings of up to 63% per water heater1 and up to 11% of residential energy use (EIA 2009). However, significant barriers must be overcome before this technology will reach widespread adoption in the Pacific Northwest region and nationwide. One barrier is that the demand response (DR) performance and characteristics of HPWHs is unknown. Previous research has demonstrated the potential of electric resistance water heaters (ERWHs) to provide significant grid stability and control benefits through demand-side management, or DR, strategies (Diao et al. 2012). However, if ERWHs are to be replaced with HPWHs to improve residential energy efficiency, it is important to understand the DR characteristics of HPWHs and how these characteristics will impact DR programs and overall grid stability now and in the future. This project evaluates and documents the DR performance of an HPWH as compared to an ERWH for two primary types of DR events: peak curtailments and balancing reserves. The experiments were conducted with General Electric (GE) second-generation Brillion-enabled GeoSpring hybrid water heaters in the Pacific Northwest National Laboratory (PNNL) Lab Homes2, with one GE GeoSpring water heater operating in Standard electric resistance mode to represent the baseline and one GE GeoSpring water heater operating in Heat Pump mode to provide the comparison to heat pump-only DR. Signals were sent simultaneously to the two water heaters in the side-by-side PNNL Lab Homes under highly controlled, simulated occupancy conditions. It is expected that Hybrid DR performance, which would engage both the heat pump and electric elements, could be interpolated from these two experimental extremes.