Electric to Electric Central HPWH Measure Package Development

The objective of this project is to support the development of a new central heat pump water heater (“HPWH”) measure package, to enable central HPWH projects where the baseline water heating system is electric (including electric resistance storage) or code minimum electric and HPWH baselines in new construction and major alterations. Central HPWH systems use one (1) or more heat pump units (unitary or split system) to heat domestic hot water for multifamily and commercial buildings. Compared to electric resistance or lower efficiency HPWH baselines, high efficiency central HPWHs can deliver the same hot water with significantly lower electricity use by operating at higher coefficients of performance (“COP”) or efficiency ratings.This project is unique because it addresses a documented gap in current California (“CA”) measure offerings: existing central HPWH measures and supporting analyses are largely oriented toward gas baselines and do not provide a pathway to claim savings for electric-to-electric applications, particularly under “Title 24 (“T24”) Part 6” electric and blended baselines for new construction. The work conducted under this project will define appropriate baseline and measure cases for central HPWHs across applicable building types, including how “blended” T24 baselines (weighted average baseline based on statewide mix of new construction systems using gas versus electric central water heating systems) should be represented, where applicable, and will develop defensible savings estimates using “EnergyPlus” Database of Energy Efficient Resources (“DEER”) prototypes. This work is being pursued to support a short-term program need identified by “DNV Group’s” midstream program team, with CA Investor-Owned Utility (“IOU”) interest, particularly Southern California Edison (“SCE”), to accelerate a measure package that can be implemented and advanced through stakeholder review.The research questions are:1.    What are the appropriate T24 and market baselines and measure cases for electric-to-electric central HPWH applications? 2.    How can these cases be simulated consistently in EnergyPlus DEER prototypes to produce measure package ready savings results? 3.    What are the incremental costs required for this switch? Is the measure cost effective? This project benefits utility programs that want to promote efficient central HPWH systems as retrofits for existing electric resistance central boilers. Current measure packages in the California electronic Technical Reference Manual (“eTRM”) address fuel substitution where central HPWH systems replace gas boilers, but do not have a corollary where the existing system is an electric resistance central water heating system. Measure packages do exist for unitary electric systems being replaced with high efficiency HPWHs, but not for central systems that may combine multiple water heaters in a central plant. By defining clear baseline/measure cases and providing DEER prototype EnergyPlus methods, utilities can claim defensible kilowatt hour (“kWh”) and kilowatt (“kW”) impacts and implement incentives through midstream and other delivery channels. The measure supports electrification with efficiency by encouraging high efficiency central HPWH systems that exceed code minimum performance, reducing electricity use relative to electric resistance or lower efficiency HPWH baselines. It also supports load flexibility because central domestic hot water (“DHW”) storage can shift heat pump operation away from peak periods using straightforward control strategies, improving alignment with grid decarbonization and portfolio needs. TRC (or the “Project Team”) will deliver a measure package proposal support package (baseline decision logic, measure eligibility specification, DEER/EnergyPlus modeling method + files/results, and cost documentation) as part of the “Draft Report” and “Final Report”. The Project Team will also complete a structured handoff with the California Technical Forum (“Cal TF”)  so they can proceed with measure package drafting.The existing approved measure packages related to this work referred to above, consist of the following: SWWH014, Heat Pump Water Heater, ResidentialSWWH025, Heat Pump Water Heater, Residential, Fuel SubstitutionSWWH027, Heat Pump Water Heater, Commercial, Fuel SubstitutionSWWH028, Large Heat Pump Water Heater, Commercial and Multifamily, Fuel Substitution and SWWH031, Heat Pump Water Heater, Commercial