{"query_echo":{"q":"","filters":{"analysis_type":["technical assumptions"]},"warnings":[{"code":"facet_value_not_in_vocabulary","message":"Value 'technical assumptions' for facet 'analysis_type' is not in the controlled vocabulary."}]},"total":{"value":6,"relation":"eq"},"page":1,"page_size":20,"self":"https://climateinsightsdirectory.org/api/v1/search?analysis_type=technical+assumptions","stability":"beta","ai_marking":{"digital_source_type":{"uri":"http://cv.iptc.org/newscodes/digitalsourcetype/trainedAlgorithmicMedia","name":"Created using Generative AI"},"notice":"Summary and key insights are generated using artificial intelligence."},"results":[{"id":"rmi-000729","url":"https://climateinsightsdirectory.org/document/rmi-000729","title":"Assumptions used in the California heat pump analysis","publisher":{"name":"RMI","organization":"rmi"},"document_type":"fact sheet","language":"en","date_published":null,"source_url":"https://rmi.org/wp-content/uploads/2025/04/Assumptions-used-in-the-California-heat-pump-analysis.pdf","generator":"Climate Insights Directory","generated_fields":["summary","key_insights","climate_tags","analysis_type"],"summary":{"text":"The document details the baseline and new system efficiencies for air source heat pumps (ASHP) and heat pump water heaters (HPWH), the use of NREL ResStock for hourly energy load profiles, and the specific utility rates for electricity, natural gas, and propane applied across California's climate zones.","ai_generated":true,"unit":"rmi-000729#summary","date_modified":"2026-10-23"},"key_insights":[{"text":"The analysis assumes specific efficiency ratings for current and new systems: current gas/propane furnaces are rated at 85% AFUE and current AC at 13 SEER2, while new ASHPs are rated at 16 SEER2 with HSPF2 ratings of 8 (IECC climates 2-4) or 9 (IECC climates 5-6). New heat pump water heaters (HPWH) are assumed to have a 3.7 UEF and 330% effective efficiency in hybrid mode, compared to current gas/propane water heaters at 0.70 UEF.","ai_generated":true,"unit":"rmi-000729#insight-1","date_modified":"2026-10-23"},{"text":"Hourly energy load profiles for typical single-family homes were sourced from the National Renewable Energy Laboratory’s (NREL) ResStock. For cold climate heat pumps in IECC climates 5 and 6, performance was based on an average subset of 100 common ASHPs from the Northeast Energy Efficiency Partnerships’ database, with electric resistance heating covering any unmet load.","ai_generated":true,"unit":"rmi-000729#insight-2","date_modified":"2026-10-23"},{"text":"The analysis utilizes specific energy rates, including a national-average propane rate of $2.51/gallon and weighted average natural gas rates for SCG, PG&E, and SDG&E. Electricity rates are sourced from Arcadia’s Signal database, with different rate plans applied for 'Pre ASHP or HPWH' and 'Post ASHP or HPWH' scenarios across various utilities including SCE, PG&E, SDG&E, LADWP, SMUD, and Imperial Residential.","ai_generated":true,"unit":"rmi-000729#insight-3","date_modified":"2026-10-23"}],"climate_tags":["energy efficiency","electricity price","natural gas","decarbonization"],"geography_discussed":[],"frame_perspective":[],"analysis_type":["technical assumptions"]},{"id":"rmi-000751","url":"https://climateinsightsdirectory.org/document/rmi-000751","title":"Lower Bills, Better Grids: Heat Pump Benefits for Homes Heating with Electric Resistance","publisher":{"name":"RMI","organization":"rmi"},"document_type":"fact sheet","language":"en","date_published":null,"source_url":"https://rmi.org/wp-content/uploads/2026/03/ER-to-HP-Article-Assumptions.pdf","generator":"Climate Insights Directory","generated_fields":["summary","key_insights","climate_tags","analysis_type"],"summary":{"text":"The document specifies the technical parameters used for modeling the transition from electric resistance heating to heat pumps in the United States. It details rated efficiencies for space and water heating systems, the use of EIA RECS 2020 microdata and NREL ResStock for home archetypes and load profiles, and the methodology for calculating electric volumetric prices based on 2024 EIA residential state-average revenue.","ai_generated":true,"unit":"rmi-000751#summary","date_modified":"2026-10-23"},"key_insights":[{"text":"The analysis uses specific rated efficiency benchmarks for heating and cooling systems, including a 1.0 AFUE for electric resistance space heat and varying SEER2/HSPF2 ratings for air-source heat pumps (ASHP) depending on whether they are ducted or ductless.","ai_generated":true,"unit":"rmi-000751#insight-1","date_modified":"2026-10-23"},{"text":"Home archetypes and energy load profiles are derived from the US Energy Information Administration’s (EIA) 2020 Residential Energy Consumption Survey (RECS) microdata and the National Renewable Energy Laboratory’s (NREL) ResStock, accounting for variables such as building type, year, and household income across different climate zones and states.","ai_generated":true,"unit":"rmi-000751#insight-2","date_modified":"2026-10-23"},{"text":"Electric volumetric prices for the analysis were determined by taking the EIA’s 2024 residential state-average total revenue, subtracting utility fixed charge revenue, and dividing the result by residential sales in kWh.","ai_generated":true,"unit":"rmi-000751#insight-3","date_modified":"2026-10-23"}],"climate_tags":["heat pump","energy efficiency"],"geography_discussed":[],"frame_perspective":[],"analysis_type":["technical assumptions"]},{"id":"rmi-000759","url":"https://climateinsightsdirectory.org/document/rmi-000759","title":"Lower Bills, Cleaner Air: Heat Pump Benefits for Homes Relying on Delivered Fuels","publisher":{"name":"RMI","organization":"rmi"},"document_type":"fact sheet","language":"en","date_published":null,"source_url":"https://rmi.org/wp-content/uploads/2025/04/Heat-Pump-vs-Delivered-Fuel-Analysis-Assumptions.pdf","generator":"Climate Insights Directory","generated_fields":["summary","key_insights","climate_tags","analysis_type"],"summary":{"text":"The document details the methodology and assumptions for a comparative analysis of heat pumps versus delivered fuels in US homes. It specifies the use of 2020 EIA RECS microdata for building archetypes, 2024 state-average energy prices, and specific efficiency ratings (HSPF2, SEER2, and UEF) for air source heat pumps (ASHP) and heat pump water heaters (HPWH) across different climate zones. Hourly energy load profiles were sourced from NREL's ResStock, with ASHP performance curves based on TMY3 temperature data and the Northeast Energy Efficiency Partnerships' database.","ai_generated":true,"unit":"rmi-000759#summary","date_modified":"2026-10-23"},"key_insights":[{"text":"The analysis uses building stock archetypes based on 2020 US Energy Information Administration (EIA) Residential Energy Consumption (RECS) microdata, accounting for building type, year, heating fuel, AC type, and household income across state climate zones.","ai_generated":true,"unit":"rmi-000759#insight-1","date_modified":"2026-10-23"},{"text":"Energy price assumptions are based on 2024 state-average volumetric prices for electricity and delivered fuels, with electric prices derived by subtracting utility fixed charge revenue from total revenue and dividing by residential sales.","ai_generated":true,"unit":"rmi-000759#insight-2","date_modified":"2026-10-23"},{"text":"Heat pump efficiency assumptions vary by equipment type and climate zone: ducted ASHPs have an HSPF2 of 8 and SEER2 of 17 in zones 1–4, and HSPF2 of 9 and SEER2 of 16 in zones 5 and above; ductless ASHPs have an HSPF2 of 8.5 and SEER2 of 19 in zones 1–4, and HSPF2 of 9.5 and SEER2 of 18 in zones 5 and above. Heat pump water heaters (HPWH) are assigned a uniform energy factor (UEF) of 3.7.","ai_generated":true,"unit":"rmi-000759#insight-3","date_modified":"2026-10-23"},{"text":"Hourly energy load profiles were sourced from NREL's ResStock, while cold climate ASHP performance curves were derived from an average subset of 100 common models in the Northeast Energy Efficiency Partnerships' database.","ai_generated":true,"unit":"rmi-000759#insight-4","date_modified":"2026-10-23"}],"climate_tags":["energy efficiency"],"geography_discussed":[],"frame_perspective":[],"analysis_type":["technical assumptions","methodology"]},{"id":"rmi-000801","url":"https://climateinsightsdirectory.org/document/rmi-000801","title":"rmi-electrification-rate-design-analysis-assumptions-66a0b39b031ddf3e.pdf","publisher":{"name":"RMI","organization":"rmi"},"document_type":"report","language":"en","date_published":null,"source_url":"https://rmi.org/app/uploads/2026/06/RMI-Electrification-Rate-Design-Analysis-Assumptions.pdf","generator":"Climate Insights Directory","generated_fields":["summary","key_insights","climate_tags","analysis_type"],"summary":{"text":"The document describes a framework for calculating residential utility bills by combining NREL ResStock building load data with electric and gas tariff data from Genability and RateAcuity. It details specific adjustments made to tariffs for Xcel Energy (Minnesota), Pepco (Maryland), Central Maine Power (Maine), and Eversource Energy (Massachusetts) to ensure analytical consistency. The analysis specifically models upgrades to high-efficiency cold-climate air-to-air heat pumps and evaluates the impact of 'electrification-friendly' rate designs on customer costs.","ai_generated":true,"unit":"rmi-000801#summary","date_modified":"2026-10-23"},"key_insights":[{"text":"RMI's analytical framework estimates residential bill changes by combining NREL ResStock's 2024.2 release load profiles—specifically 'upgrade scenario 2' for high efficiency cold-climate air-to-air heat pumps with electric backup—with tariff data from Genability and RateAcuity and EIA state-average fuel prices.","ai_generated":true,"unit":"rmi-000801#insight-1","date_modified":"2026-10-23"},{"text":"For Xcel Energy in Minnesota, RMI manually adjusted percent-based interim rate adjustment surcharges to prevent overapplication, excluding components such as the Conservation Improvement Program Adjustment, Environmental Improvement Charge, Mercury Cost Recovery, Renewable Development Fund, Affordability Surcharge, and Renewable Energy Standard Adjustment.","ai_generated":true,"unit":"rmi-000801#insight-2","date_modified":"2026-10-23"},{"text":"In the analysis for Pepco Maryland, RMI created a hypothetical 'default' flat rate with consistent volumetric charges to serve as a reference point against the existing 'electrification-friendly' rate, which features seasonally differentiated volumetric charges.","ai_generated":true,"unit":"rmi-000801#insight-3","date_modified":"2026-10-23"},{"text":"RMI estimated heat pump enrollment for Central Maine Power by applying the ratio of the utility's customers to all state electricity customers against total state heat pump data, assuming 10,000 customers are enrolled in the opt-in rate as of 2026.","ai_generated":true,"unit":"rmi-000801#insight-4","date_modified":"2026-10-23"}],"climate_tags":["heat pump"],"geography_discussed":[],"frame_perspective":[],"analysis_type":["methodology","technical assumptions"]},{"id":"ucs-000275","url":"https://climateinsightsdirectory.org/document/ucs-000275","title":"Microsoft Word - Appendix A Key Assumptions for Levelized Costs Final.doc","publisher":{"name":"Union of Concerned Scientists","organization":"union-of-concerned-scientists"},"document_type":"report","language":"en","date_published":null,"source_url":"https://www.ucs.org/sites/default/files/2019-09/Appendix-Key-Assumptions-Levelized-Costs.pdf","generator":"Climate Insights Directory","generated_fields":["summary","key_insights","climate_tags","geography_discussed","analysis_type"],"summary":{"text":"The document provides the technical and financial basis for LCOE ranges for electricity generation technologies. It specifies that all technologies are assumed to be online in 2015, with costs expressed in real 2010 dollars over a 20-year recovery period. The analysis incorporates overnight capital costs, fixed charge rates, O&M costs, and fuel price assumptions, while accounting for federal tax credits, loan guarantees for nuclear power, and future carbon prices.","ai_generated":true,"unit":"ucs-000275#summary","date_modified":"2026-10-23"},"key_insights":[{"text":"The analysis uses a standardized financial framework where all technologies are assumed to be brought online in 2015, with costs expressed in real 2010 dollars and levelized over a 20-year cost recovery period.","ai_generated":true,"unit":"ucs-000275#insight-1","date_modified":"2026-10-23"},{"text":"To reflect the financial risks associated with carbon-intensive investments, the analysis applies a 3 percent higher cost of capital to greenhouse-gas-intensive projects, such as coal-fired power plants that lack carbon capture and storage.","ai_generated":true,"unit":"ucs-000275#insight-2","date_modified":"2026-10-23"},{"text":"Fuel cost assumptions vary by technology: biomass is estimated between $30 and $65 per dry ton; coal prices are based on EIA AEO 2010 high and low side cases; and natural gas ranges are derived from NYMEX futures prices and EIA AEO 2011 forecasts using a 20 percent confidence interval.","ai_generated":true,"unit":"ucs-000275#insight-3","date_modified":"2026-10-23"},{"text":"The levelized cost of electricity (LCOE) with incentives and CO2 costs varies significantly across technologies; for example, Natural Gas CC ranges from $59 to $118/MWh, while Nuclear ranges from $91 to $167/MWh and Onshore Wind ranges from $36 to $104/MWh.","ai_generated":true,"unit":"ucs-000275#insight-4","date_modified":"2026-10-23"}],"climate_tags":["carbon price","carbon capture and storage","photovoltaics","geothermal energy","bioenergy","nuclear power","energy efficiency","climate finance","tax credit"],"geography_discussed":["United States"],"frame_perspective":[],"analysis_type":["economic assessment","technical assumptions"]},{"id":"ucs-000422","url":"https://climateinsightsdirectory.org/document/ucs-000422","title":"Climate 2030 Blueprint","publisher":{"name":"Union of Concerned Scientists","organization":"union-of-concerned-scientists"},"document_type":"report","language":"en","date_published":null,"source_url":"https://www.ucs.org/sites/default/files/2019-09/climate2030-app-e-transportation.pdf","generator":"Climate Insights Directory","generated_fields":["summary","key_insights","climate_tags","geography_discussed","analysis_type"],"summary":{"text":"The report outlines the assumptions used to model transportation emissions reductions by 2030, including fuel economy targets, the adoption of plug-in hybrids, and the deployment of cellulosic ethanol. It describes adjustments made to the AEO 2008 model to reflect more aggressive efficiency standards and the impacts of smart growth policies.","ai_generated":true,"unit":"ucs-000422#summary","date_modified":"2026-10-23"},"key_insights":[{"text":"The Blueprint sets light-duty vehicle efficiency standards equivalent to 42 miles per gallon (mpg) by 2020 and 55 mpg by 2030, although modeling suggests a 2030 efficiency equivalent of 52 mpg due to automakers paying fines to opt out of standards.","ai_generated":true,"unit":"ucs-000422#insight-1","date_modified":"2026-10-23"},{"text":"For plug-in hybrid vehicles, the model assumes a 30-mile all-electric range and that 50 percent of vehicle miles traveled (VMT) are all-electric. The incremental cost of a plug-in car compared to a hybrid-electric vehicle is projected to drop from $12,000 in 2010 to $3,400 in 2030.","ai_generated":true,"unit":"ucs-000422#insight-2","date_modified":"2026-10-23"},{"text":"Medium- and heavy-duty vehicle efficiency targets are set at 8 mpg by 2020 and 9.5 mpg by 2030 for heavy-duty vehicles, and 11 mpg by 2020 and 16 mpg by 2030 for medium-duty vehicles.","ai_generated":true,"unit":"ucs-000422#insight-3","date_modified":"2026-10-23"},{"text":"The model assumes that replacing HFC-134a with HFC-152a and using variable-speed compressor motors in vehicle air-conditioning systems can reduce CO2 equivalent emissions by 8 grams per mile at a cost of $50 per vehicle.","ai_generated":true,"unit":"ucs-000422#insight-4","date_modified":"2026-10-23"},{"text":"To account for land-use changes, the model assumes food-based biofuels provide no net carbon benefit compared to gasoline, while biofuels from waste or energy crops achieve a 100 percent reduction in carbon emissions.","ai_generated":true,"unit":"ucs-000422#insight-5","date_modified":"2026-10-23"},{"text":"Smart growth strategies are modeled by reducing the annual growth rate of light-duty VMT to 0.9 percent (down from 1.4 percent in the Reference case) and shifting 2.5 percent of freight travel from trucks to rail by 2030.","ai_generated":true,"unit":"ucs-000422#insight-6","date_modified":"2026-10-23"}],"climate_tags":["battery electric vehicle","fuel cell vehicle","biofuel","land-use change"],"geography_discussed":["California"],"frame_perspective":[],"analysis_type":["technical assumptions","policy modeling","scenario analysis"]}]}