In the oldest (pre-1978) vintage, all three measures analyzed (dual fuel heat pump with existing furnace, standard heat pump space heater, and high efficiency heat pump space heater) were found to be cost-effective using the LSC metric in all climate zones. When using the On-Bill metric, the measures still remained cost-effective in most climate zones.In the newer (1978-1991 and 1992-2010) vintages, the dual fuel heat pump (DFHP Existing Furnace) and the standard efficiency HPSH were found to be cost-effective based on LSC in all cases except for Climate Zone 15 when using both the standard and California Alternate Rates for Energy (CARE) tariff.
The study assumes utility rates escalate over time. Because of the difficulty in predicting how the rates will change, the analysis presents two escalation scenarios (modest and high gas escalation) to represent a range of outcomes. The study also includes a Zero NOx scenario sensitivity analysis due to the Bay Area Air Quality Management District (BAAD) Zero NOx rule, and the proposed California Air Resource Board or South Coast Air Quality Management District (SCAQMD) Zero-NOx rules.
The full suite of resources (report and dataset of all results) can be downloaded here. The webinar materials and recording can be accessed here.