Residential Measure Details

Residential Measure Bundles by End Use

Around 40 residential-sector measures are analyzed in the 2021 Power Plan. These measure bundles do not and should not dictate the way measures are bundled for programmatic implementation. Many of the residential-sector measures are reviewed by the RTF and the 2021 Plan supply curves incorporate those most recent data as of March 2020. However, in some cases, the final measures included in the 2021 Power Plan may be consolidated from the RTF measure list. For example, the RTF’s analysis for heat pump water heaters is quite granular, with savings variation by install location, heating zone, and efficiency level. Differences by heating zone are relatively small and statistical significance is limited between heating zones two and three, so the measure is collapsed into only differentiating by install location. Also, to avoid double counting savings between tiers, the efficiency of higher tiers is incremental to the previous tier. If the levelized cost for the more efficient tier is less than the lower tier, only the more efficient tiers are included. The measure bundles, each of which has an individual Excel workbook, are provided by end use in the table below.

Residential Measure Bundles by End Use

Major and New Residential Measures

The residential measure with the greatest potential in the 2021 Plan is heat pump water heaters (over 400 average megawatts). Heat pump water heaters were also significant in the Seventh Power Plan. Since the Seventh Power Plan, more products and high efficiency units have become available, including split-system units that are highly efficient and require less indoor space allowing for greater applicability in multifamily dwellings. Other large sources of savings include weatherization measures, dryers, and ductless heat pumps. Heat pump dryers, though included in the Seventh Power Plan, have significantly more potential in the 2021 Plan, given better understanding of the technology and increased product availability.

Unlike in the Seventh Power Plan, residential lighting potential is not as significant. This market has been significantly transformed by the prevalence of LED bulbs in the market, where, according to NEEA’s 2019 lighting market analysis study, nearly 70 percent of all general purpose and reflector bulbs sold were LED. In addition, in Washington, high-efficacy bulbs are now required by statute, further reducing the potential.[1] Still, potential remains, particularly for integral LED fixtures, certain specialty bulb applications, and pin-based lamps.

The 2021 Plan incorporated a number of new measures compared to the Seventh Power Plan, as provided in table below. For measures that were included in both the prior and current plans, oftentimes new permutations or efficiency levels were added for the 2021 Plan.

Residential Measures New to the 2021 Plan

Residential Measures Not Included in 2021 Plan

There are several energy efficiency measures that were not included in the 2021 Plan due to limited data or resources. Some of these measures for the residential sector are: thin-glass triple pane windows, integrated CO2 space and water heat pumps, lighting occupancy sensors, shell improvements in new construction, ENERGY STAR soundbars, efficient portable spas. Although excluded from the 2021 Plan, these measures may be feasible for energy efficiency programs to pursue. Whole building approaches for both estimating potential and for use in programs could result in deeper savings at lower costs. 

[1] Note, at the time of the supply curve development, the federal standard was as finalized at the end of 2019 – that is, 45 lumens/watt is not required for general purpose or specialty incandescent bulbs outside of Washington.