Accelerating Decarbonization in the United States Technology, Policy, and Societal Dimensions (2024) / Chapter Skim
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7 The Built Environment
7 The Built Environment
Pages 350-416
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From page 350... ...
A broad range of public policies and private actors make decisions fundamental to the built environment that, in turn, define how, how much, and what kind of energy is consumed. The overall reduction of total energy demand in the built environment through energy-efficiency improvements and advanced energy management is as critical for U.S.
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From page 351... ...
There is an equally critical need for national investment in increased research, development, demonstration (RD&D) , and commercialization of building technologies for homes, commercial buildings, and grid-interactive efficient buildings (GEBs)
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From page 352... ...
Reducing overall demand ensures that energy production decreasingly relies on any carbon-based sources, but also promotes management of a clean electricity grid. This approach begins with improving all buildings' energy efficiency.
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Specifically in relation to overarching goals at the time, the report recommended the reduction of overall energy consumption in existing buildings by 3 percent per year over the next decade to achieve a 30 percent total reduction, and in new construction by 50 percent total, both by 2030. As described in the report, the strategy for meeting these 353 A00026 -- Accelerating Decarbonization in the United States_CH07.indd 353 3/29/24 4:53 PM
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From page 354... ...
Last, the committee provided specific measurable targets for one strategy toward these decarbonization goals. The primary technological vehicle for reaching the report's targets is the electrification of space and water heating; the report set a target of increasing electric heat pumps' share of heating and hot water equipment to 25 percent in residential buildings and 15 percent in commercial buildings by 2030 (NASEM 2021a, p.
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From page 355... ...
Emissions from buildings have already been falling since 2005 owing largely to increases in energy efficiency, even though both the number and size of residential and commercial buildings have continued to increase. The potential for much deeper emissions reductions is large.
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From page 356... ...
. Through direct combustion alone, buildings consumed an aggregate 7.2 quadrillion BTUs in energy from natural gas, heating oils, and other carbon-based fuels according to recent consumption surveys, almost two-thirds of it coming from the housing stock and the remainder from commercial buildings (Table 7-1)
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From page 357... ...
SOURCE: Tabulations of 2015 Residential Energy Consumption Surveys and 2018 Commercial Buildings, courtesy of the U.S. Energy Information Administration, May 2018 and December 2022 (EIA 2018, 2022a)
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From page 358... ...
. SOURCE: Tabulations of 2018 Commercial Buildings and 2020 Residential Energy Consumption Surveys, courtesy of the U.S.
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From page 359... ...
Regarding the second objective of decreased total energy consumption, new com mercial and residential buildings are built to stricter energy performance require ments, using more efficient equipment and appliances and often with their own energy production potential via distributed, building-level renewable energy instal lations. Consequently, the average energy consumption (and certainly the energy intensity)
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From page 360... ...
20000 15000 10000 5000 0 End-Use Energy Consumed by the Residential Sector Total Energy Consumed by the Residential Sector End-Use Energy Consumed by the Commercial Sector Total Energy Consumed by the Commercial Sector FIGURE 7-1 Primary end use and total energy consumption for residential and commercial buildings, 1949–2021 (trillion BTUs)
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From page 361... ...
The committee's focus on heat pumps as the vehicle for electrification of current space and water heating's energy consumption is also supported by the evidence, given current technological options for immediate electrification and the financial feasibility of their installation. The gap between heat pumps' diffusion and the rates of this technology's adoption that would be necessary to meet the stated decarbonization goals is significant.
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. If all new homes were required to have heat pumps, the housing stock would meet the committee's heat pump diffusion rate targets by 2028, assuming the average construction rates of approximately 1.2 million new homes built each year continues (U.S.
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New home counts after 2020 assume 1.2 million completions annually. SOURCES: Data from 2009, 2015, and 2020 Residential Energy Consumption Surveys, courtesy of the U.S.
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If electrification of space heating equipment in existing housing persists at the same acceleration in the future, the residential stock could hit 25 percent total adoption rates -- that is, including existing and new housing barring any new policy intervention -- by 2039. Assuming a 50 percent reduction in space heating energy consumption in these homes owing to heat pump installation, this also translates to about a 7.4 percent reduction in total residential energy demand by 2038 from heat pump adoption alone -- below the committee's 30 percent reduction goal or the administration's more varying 18–32 percent goal (Energy Saver 2022)
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From page 365... ...
All Owners All Renters SF Owners SF Renters All SF MF Owners MF Renters All MF Income group 14.4% 14.8% 13.5% 15.1% 14.7% 15% 9.5% 12.9% 12.5% Heat pump homes 100.0% 69.1% 30.9% 66.8% 10.6% 77.4% 2.3% 20.3% 22.6% NOTE: MF = multifamily; SF = single family. SOURCE: Tabulations of 2020 Residential Energy Consumption Surveys, courtesy of the U.S.
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From page 366... ...
. Heat pumps are also more than three times more likely to be found in single-family homes than multifamily apartment buildings.
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From page 367... ...
10 For households with incomes under 200 percent of poverty thresholds, median energy costs across all energy types are 32.8 percent of median housing costs compared to 22.3 percent of households with incomes above per 2021 AHS housing cost data. Per 2015 Residential Energy Consumption Survey (RECS)
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From page 368... ...
Finding 7-3: The committee's original recommendations for increased investments in WAP are meant to prioritize decarbonization efforts for households experiencing a range of energy hardships. However, defining the population and articulating outcomes (in both removal of carbon-based energy sources as well as improving energy efficiency to reduce overall energy burden)
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From page 369... ...
Significant intervention is needed to make up the gaps between current conditions, the committee's more detailed intervention targets, and the committee's broad goals for 2030 as stated in the first report. This holds true for all the quantified gaps in overall energy efficiency (particularly for the least efficient older building stock)
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From page 370... ...
Each provides some achievement against the committee's original 2030 energy reduc tion goals, although none as much as the federal investments in the past 2 years.12 National Policy Changes In particular, the IIJA authorized $3.5 billion to WAP until expended (§40551) -- which the White House estimates will aid 700,000 income-eligible households over the next decade based on past WAP mean expenditures per unit.13 However, a likely scenario given past expenditure rates is more than 322,000 homes weatherized, resulting in an additional 8 tBTUs reduced in total energy consumption (6.5 tBTUs in natural gas consumption)
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Current projections for new homes benefiting from the 45L tax credits can also assume to add 650,000 heat pumps at a minimum to the housing stock (Smedick et al.
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From page 372... ...
IIJA funding for WAP will provide an opportunity to target eligible households and energy-reducing improvements, including electrification, more effectively. IRA tax credits and rebates are also significant: IRA incentives for heat pump installations will meet the committee's targets by 2029 (a decade ahead of business-as-usual adoption rates)
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From page 373... ...
. This may not be additive -- that is, many of the households and homebuilders that take the tax credits or rebates may have been purchasing heat pumps anyway.
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From page 374... ...
. A few states have also incented or mandated distributed renewable energy production.19 For example, California's goal of achieving zero net energy for new residential buildings by 2020 and by 2030 for commercial buildings has resulted in codes with prescriptive requirements for heat pumps (CPUC n.d.)
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From page 375... ...
For example, California recently prohibited natural gas heating equipment beginning in 2030. California has also set goals for the installation of heat pumps and set aside funds for this effort.
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The Department of Energy should develop rules for the implementation of energy programs (particularly those funded through the Inflation Reduction Act [IRA]
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For example, state energy offices should coordinate with community services, housing, and community development agencies to better target weatherization assis tance funds as well as state rebate programs. Furthermore, local building inspection and housing departments should be utilized to better support building improvements in new and existing residential and commercial buildings.
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From page 378... ...
should dedicate a portion of their available funds to monitoring the effectiveness of this technical assistance as well as tracking its outcomes in energy savings or electrification rates. BROADER DECARBONIZATION STRATEGIES FOR THE BUILT ENVIRONMENT The opportunities for decarbonization in the built environment rest on more than just addressing buildings' energy consumption.
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From page 379... ...
Further experimentation, technical resources, funding, and financ ing resources are needed for community distributed renewable projects. Financing alternatives may include revolving loan funds and green banks, to be paid back from production revenues and household energy savings.
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From page 380... ...
. A more aggressive target for increased energy efficiency in buildings and the built environment would reduce demand for heating, cooling, and transport electricity.
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From page 381... ...
. Of these savings, 70 percent come from a dozen products that could be accelerated to achieve Energy Star performance in the top 25 percent of their market, including residential water heaters, heat pumps/central air conditioners, boilers and furnaces, refrigerators, as well as commercial/industrial fans, electric motors, transformers, air compressors, and packaged unitary air conditioners and heat pumps.
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From page 382... ...
that includes air conditioner upgrades to heat pumps for heating and cooling; oil heating system upgrades; electric resistance heating system upgrades; gas heating system upgrades in mild climates; and, only then, gas heating system upgrades in cold climates with hybrid fuel capability for extremely cold days -- each of these with cooling as needed and potentially integrated hot water. DOE's Residential Cold Climate Heat Pump Challenge is intended for rapidly improving cold climate heat pumps so that hybrid heat may not be needed in a decade, and reducing the installed cost of geothermal heat pumps may be even more impactful for reducing the large carbon footprint of heating and cooling in the United States (DOE n.d.)
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From page 383... ...
5.7 quads of reduced annual energy demand, 265 MMtCO2 of reduced annual emissions. The design, engineering, and construction professions have been delivering net-zero new buildings wherever clients or codes mandate, by combining very low energy use per square foot requirements with on-site or purchased renewable energy sources.
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From page 384... ...
The largest energy demands in residential and commercial buildings are for heating, cooling, ventilation, and lighting -- each of which can be measurably reduced through thermal and air tightness improvements in building roofs, walls, windows, and foundations, which directly impact the sizing and performance of mechanical and electrical equipment. Retrofitting the nation's existing buildings to improve their energy efficiency would require significant expansion of relevant manufacturing and training, and would need to address the barriers and disruptions that accompany most retrofits, as well as the up-front capital cost, even when reduced operating 384 A00026 -- Accelerating Decarbonization in the United States_CH07.indd 384 3/29/24 4:53 PM
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. The IIJA and IRA provide a significant start by a commitment to retrofitting 1.3–2.5 million buildings inhabited by low-income households with heat pumps.
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From page 386... ...
and $0.2 billion for states to establish training and education programs for contractors who install home energy efficiency and electrification improvements (§50123) is a critical start and could be expanded to address existing commercial buildings as well.
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From page 387... ...
The IoT has created the potential for a transformational change in society but has experienced a surprisingly slow pace of integration into buildings. With each piece of mechanical equipment and every appliance, light fixture, and window control having an IP address, the ability to monitor and control energy consumption while ensuring a high level of occupant service provides unprece dented opportunities for increasing the energy efficiency of buildings.
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From page 388... ...
Local and state codes will need to be modified to support HFC-free equipment. Increased federal funding to develop and deploy the next generation of refrigerants would help the United States to remain a leader in the manufacturing of heat pumps, refrigerators, and air conditioners, while helping the United States meet or exceed its target for reducing refrigerant emissions.
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. However, if electrification in buildings is combined with high energy efficiency, on-site energy storage, and smart technologies with grid integration, the energy and GHG emissions reductions can be substantial.
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From page 390... ...
. Community Policies and Actions for Rapid Decarbonization in the United States In addition to modifications to buildings for decarbonization, federal, state, and local policies could promote land use policies that substantially increase the energy efficiency of buildings and infrastructure as described in the next four sections on mixed-use, transit-oriented development; community renewables with micro-grids; smart surfaces; and innovation, research, and rapid development of district energy through GEBs with thermal energy distribution and storage systems.
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From page 391... ...
identified the range of environmental consequences of today's subsidized sprawl beyond the growing demand for fossil or electric energy sources -- including atmospheric pollution; hydrographic system alteration, increased impervious surfaces and flooding; and loss of biodiversity, forests, and agriculture. Addi tional social costs include increased spatial segregation, commuting time, and demands for automobile ownership, as well as diminished access to jobs and amenities.
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. Moreover, bundling electrification with energy efficiency retrofits reduces the needed size and operational energy demands of the new electrical equipment such as heat pumps.
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From page 393... ...
has analyzed how trade-offs and synergies among building efficiency, electrification, and the various options for electric power generation affect energy demand and greenhouse emissions. LBNL concluded that the most aggressive strategies would bundle building efficiency, electrification, and grid decarbonization to offer approximately 90 percent reductions in carbon emis sions from the built environment by 2050 (Figure 7-6; Langevin et al.
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From page 394... ...
The integrated deployment of green, porous, and reflective surfaces, as well as trees and solar PV, allows cities to save money, mitigate and adapt to climate change, reduce public health and equity risks, and cut urban heat and flooding. The Smart Surfaces Coalition has quantified the major contributions of smarter surfaces to neighborhood quality of life, reducing urban heat island temperatures over 2°C, reducing flooding devastation, while also reducing or sequestering carbon and generating electricity (SSC 2022; Table 7-7)
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From page 395... ...
4.0 quads of reduced annual energy demand, 150 MMtCO2 of reduced annual emissions. There are abundant alternatives to the use of electricity for space heating, hot water, and even cooling loads that combined are responsible for 37 percent to 46 percent of the to tal energy consumed in the United States (EIA 2022a)
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From page 396... ...
District heating and cooling systems that combine ground source heat pumps with PV and building energy storage systems have resulted in major residential carbon savings in Europe and the United Kingdom, under climatic conditions present in many regions of the United States (Litjens et al.
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From page 397... ...
In addition to ensuring that new transmission infrastructures improve communi ties, there are two key opportunities that depend on integration of the grid and the built environment beyond a simple utility service: advancing buildings (and their cars) as batteries and peak load managers for grid resilience; and incorporat ing distributed renewables and district energy with GEBs into an interconnected grid of grids.
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From page 398... ...
(See NASEM 2021b.) To realize the potential of buildings as batteries and peak load managers for grid resilience, the United States would need to increase long-term RD&D investments in a number of technologies, including • Heat pumps for integrated heating, cooling, and hot water (buildings)
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From page 399... ...
The IRA dedicates $65 billion to funds for grid reliability and resiliency actions and supports a Grid Deployment Office for critical minerals and supply chains for clean energy technology; key technologies including carbon capture, hydrogen, direct air capture, and energy efficiency; and energy demonstration projects outlined in the bipartisan Energy Act of 2020. These federal funding opportunities do not include a focused RD&D program to develop grids that fully engage distributed renewables, storage, and GEBs as an integral player in the grid.
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From page 400... ...
, and multiple states have launched low- and moderate-income solar programs to facilitate community solar by helping to overcome barriers such as lack of access to capital, insufficient tax burden to take advantage of tax credits, the large fraction of renters who are often ineligible for incentives, frustrating interconnection policies, and lack of familiarity with solar products (Mai et al.
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(2022) and Wood Mackenzie and Solar 401 Energy Industries Association (2021)
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From page 402... ...
subnational mandates and incentives for zero energy new homes and commercial buildings; and (3) acceler ated retrofits of existing homes and commercial buildings, with benchmarking 402 A00026 -- Accelerating Decarbonization in the United States_CH07.indd 402 3/29/24 4:54 PM
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From page 403... ...
There is an equally critical need for national investment in RD&D of low-carbon and smart technologies, and systems for homes, commercial buildings, and GEBs with distributed renewables and storage. Beyond the building level, there is the challenging but transformational pursuit of community-level decarbonization of buildings and community infrastructures, including incentivizing mixed-use walkable infill instead of sprawl communities; accelerating building and commu nity renewables; and innovating in addressing low-temperature thermal (heat ing and cooling demands)
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From page 404... ...
A broad range of public policies and private decisions associated with the built envi ronment significantly define how, how much, and what kind of energy is consumed in the United States. For example, improvements in energy efficiency within new buildings have modestly offset the sheer growth in these buildings' numbers.
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From page 405... ...
Consideration of the interactions across intervention types and their resulting contributions to both comprehensive decarbonization of the sector and the inequitable access and impacts across populations -- particularly for low-in come, energy-burdened, energy-insecure households; households in severely inadequate housing; and other disadvantaged groups. For the next decade, investments in market transformation across all building and community intervention points are needed to meet the goal of reducing the built environment's contribution to carbon-based energy demand and its result ing GHG emissions by 2050.
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From page 406... ...
Larger incentives must be allotted to building audit services and to owner and occupant service management to ensure the technologically appropriate selection and installation order of decarbonization technologies that are suited to the housing unit and house hold or owner capacity. For example, the creation of additional targets for 2040–2043 could ensure a higher adoption rate of heat pumps beyond the 25 percent and 15 percent targets laid out in the committee's first report for residential and commercial buildings by 2030.
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From page 407... ...
Objective(s) Categories Short-Form Implementing Addressed by Addressed by Addressed by Recommendation Recommendation Recommendation Recommendation Recommendation 7-1: Ensure Clarity Department of • Buildings • Greenhouse Rigorous and and Consistency Energy (DOE)
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From page 408... ...
Objective(s) Categories Short-Form Implementing Addressed by Addressed by Addressed by Recommendation Recommendation Recommendation Recommendation Recommendation 7-3: Expand and DOE • Buildings • GHG Rigorous and Evaluate the reductions Transparent Weatherization • Equity Analysis and Assistance • Health Reporting Program for Adaptive Management Ensuring Procedural Equity in Planning and Siting New Infrastructure and Programs Tightened Targets for the Buildings and Industrial Sectors and a Backstop for the Transport Sector 7-4: Coordinate State and • Buildings • Equity Tightened Targets Subnational municipal • Non-federal • Employment for the Buildings Government government actors and Industrial Agencies to Align offices Sectors and a Decarbonization Backstop for the Policies and Transport Sector Implementation Building the Needed Workforce and Capacity 408 A00026 -- Accelerating Decarbonization in the United States_CH07.indd 408 3/29/24 4:54 PM
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From page 409... ...
Objective(s) Categories Short-Form Implementing Addressed by Addressed by Addressed by Recommendation Recommendation Recommendation Recommendation Recommendation 7-5: Build Capacity Congress • Buildings • GHG A Broadened for States and • Non-federal reductions Policy Portfolio Municipalities actors • Equity Rigorous and to Adopt and • Health Transparent Enforce Increased • Employment Analysis and Regulatory Rigor Reporting for Buildings and for Adaptive Equipment Management Tightened Targets for the Buildings and Industrial Sectors and a Backstop for the Transport Sector Building the Needed Workforce and Capacity 7-6: Increase Congress • Buildings • Equity Siting and Research, • Non-federal • Health Permitting Reforms Development, actors • Employment for Interstate Demonstration, • Public Transmission and Deployment engagement Research, for Built Development, and Environment Demonstration Decarbonization Needs Interventions 7-7: Extend Congress; DOE • Buildings • GHG A Broadened Current reductions Policy Portfolio Decarbonization • Equity Tightened Targets Incentives Beyond • Health for the Buildings the Next Decade • Employment and Industrial While Scaling Up Sectors and a Mandates Backstop for the Transport Sector 409 A00026 -- Accelerating Decarbonization in the United States_CH07.indd 409 3/29/24 4:54 PM
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From page 410... ...
2022. State Energy Efficiency Scorecard: 2021 Progress Report.
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From page 411... ...
EERE-2016-BT-TP-0029] RIN 1904-AD71 Energy Conservation Program: Test Procedures for Central Air Conditioners and Heat Pumps." Office of Energy Efficiency and Renewable Energy, Department of Energy.
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2022. "Heat Pump Systems." Department of Energy Office of Energy Efficiency and Renewable Energy.
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2018. "Do Energy Efficiency Investments Deliver?
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2018. "Lowering Greenhouse Gas Emissions in the Built Environment by Combining Ground Source Heat Pumps, Photovoltaics and Battery Storage." Energy and Buildings 180:51–71.
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From page 415... ...
2015. "District Energy in Cities: Unlocking the Potential of Energy Efficiency and Renewable Energy." United Nations Environment Programme.
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From page 416... ...
2019. Halfway There: Energy Efficiency Can Cut Energy Use and Greenhouse Gas Emissions in Half by 2050.
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