School of Mines Lecture Notes Residential R&D and the Residential Energy Efficiency Value Gap June 14, 2011 Dr. Ren Anderson, NREL Residential Research Group NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. 1
Our Overall Vision Be the trusted source of R&D results that define and deliver reliable, costeffective systems that reduce residential energy use by 30-50%. 2
Our Technical Approach Conduct whole building research projects that create, capture, and deliver lasting value for key customers and stakeholders. 3
BA Strategic Planning Meetings SPRING: STAKEHOLDER MEETING DEFINE MARKET NEEDS THAT DRIVE SOLUTIONS SUMMER: RESEARCH UPDATE MEETING REPORT PROGRESS ON SOLUTIONS THAT MEET MARKET NEEDS FALL: RESEARCH PLANNING MEETING IDENTIFY SYSTEM PERFORMANCE GAPS LIMITING 30-50% SAVINGS 4
DESIRED OUTCOME FROM THIS MEETING DEFINE THE MARKET REQUIREMENTS FOR SOLUTIONS THAT DRAMATICALLY REDUCE RESIDENTIAL ENERGY USE DRIVEN BY VALUE CHAIN METRICS RATHER THAN SUPPLY CHAIN METRICS DRIVEN BY VOICE OF THE CUSTOMER AND KEY STAKEHOLDERS NEEDS MANAGED AND SUPPORTED BY DOE AND CONGRESS! 5
Market-Driven Value Andrew Fearne: Value Chains, University of Kent, England 6
Successful Delivery of Residential Efficiency Strategic Alignment Information Flow Mutual Trust Commitment to Customer Value 7
Cost of Improvement (k$) Broken Link: Efficiency and Home Value 25 20 15 Efficiency Value Gap Base Value Recovery 10 5 0 0 5 10 15 20 25 Cost Recovery at Resale (k$) 8
Development of a Method for Comparison of Different Home Energy Rating Systems NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.
Managing Data for Validation Studies BBIS Retrofit measures Estimated energy savings Utility billing data Research Questions How effective are the grantee programs? How do predicted savings compare to utility bills? How do retrofits contribute to total predicted savings? How do predicted savings compare to utility bills? How do retrofits contribute to total predicted savings? Audit Tool Input Files TREAT, REM, BEACON, etc. Building Characteristics What are the characteristics of homes being retrofitted? How does predicted energy use compare across software tools? How does predicted energy use compare to utility bills? What are sources of inaccuracy in energy use predictions? Field Data Repository Interpreter Format data Filter data What if scenarios Field Data Historical - Utility programs - WX programs Future - Scoring pilots - BetterBuildings Characteristics Data Field Data Repository Energy Use Data Comparative Tool Visualizaton Statistical Analysis Simulation Engines HESpro (DOE-2.1E) BEopt (DOE-2.2, E+) WX Assistant Private-sector tools
Field Data Repository Interpreter Format data Filter data What if scenarios Field Data Historical - Utility programs - WX programs Future - Scoring pilots - BetterBuildings Characteristics Data Field Data Repository Energy Use Data Comparative Tool Visualizaton Statistical Analysis Simulation Engines HESpro (DOE-2.1E) BEopt (DOE-2.2, E+) WX Assistant Private-sector tools
Timeline
Problem Statement There are a large number of state, local, and national home rating systems. These rating systems are based on different calculation methods and modeling assumptions As a result, retrofit providers often have to train their staff to use multiple rating systems to qualify for participation in different residential efficiency programs, even though these programs are in the same region, are targeting the same housing stock, and use the same retrofit measures. 13
Technical Approach The objective of this project is to develop an energy calculation method that can be used to allow different rating systems to provide consistent predictions of energy use. In this initial study two national home rating systems are compared to determine if source energy use predictions can be used to develop a consistent method for comparing different home rating systems. 14
Rating Scale Comparison: Input Alignment Initial Out-of-box comparison of Home Energy Score and HERS Differences in inputs and assumptions for Home Energy Score and HERS affect outcome In this initial comparison, inputs are aligned to extent possible with the exception of occupancy assumptions Inputs Home Energy Score HERS Floor Area, Number of Stories, Foundation Type Inputs Aligned Inputs Aligned Air Leakage Rate Inputs Aligned Inputs Aligned Foundation, Wall & Roof Properties (Type & R-Value) Inputs Aligned Inputs Aligned Window Properties (Area, Orientation, Type, U-Value & SHGC) Inputs Aligned Inputs Aligned Heating, Cooling, Hot Water Systems (Type, Fuel & Efficiency) Inputs Aligned Inputs Aligned Occupancy Inputs Not Aligned Inputs Not Aligned Thermostat Set Points (Heating, Cooling & Schedule) Inputs Not Aligned Inputs Not Aligned Ducts and Pipes (Location, Insulation & Leakage) Inputs Not Aligned Inputs Not Aligned 15
Initial Conclusion: Predicted Source Energy Use Provides a Promising Approach to Compare Different Home Energy Rating Systems Home Energy Scoring Tool Predicted Source Energy [MMBtu/yr] KEY Climate Prototype Graph Symbol 2012IECC Atlanta 2006IECC O Existing (1970s era) 2012IECC Chicago 2006IECC O Existing (1970s era) 2012IECC Houston 2006IECC O Existing (1970s era) 2012IECC Phoenix 2006IECC O Existing (1970s era) 2012IECC Seattle 2006IECC O Existing (1970s era) 500 400 300 200 100 0 Perfect Agreement 0 100 200 300 400 500 REM/Rate Predicted Source Energy[MMBtu/yr] Symbol Prototype Even without fully consistent operating assumptions there is a strong correlation between predicted source energy use for HERS and Home Energy Score! Average % Difference (All Climates) Standard Deviation [MMBtu] Existing (1970s era) 15% 44 O 2006-IECC 7% 20 2012-IECC 5% 7 16
Recommendation: Develop Uniform Home Energy Scale Based on Consistent Calculation Method for Source Energy Use This Home Typical New Home Typical Existing Home Lowest Use Home Energy Use Highest Use 17
Energy Scale Can Easily be Integrated With Rating Systems HERS Score Estimated Home Energy Use: 18
Benefits of Consistent Energy Scale Use of consistent energy information increases transparency of various state, local, and national rating systems Maintains and enhances value of existing rating systems Allows contractors and service providers to meet requirements of programs that use different rating systems by using a single calculation that demonstrates equivalence between rating systems Allows consumers to cross-compare between different rating systems Enables economies of scale to support growth of the energy retrofit industry 19
Appendix: Comparison Details Note: This initial evaluation was done without access to the final Home Energy Score API. Comparison data will be updated when the final API is released. 20
Home Energy Score Overview Home Energy Score More Energy Use Less Energy Use Simulates the rated home s annual source energy use Scores home based on bins of source energy use - Ranges of bins are based on climate Higher numbers indicate less energy use 21
HERS Scale Overview HERS Scale Higher Normalized Modified End Use Loads Lower Normalized Modified End Use Loads Calculates rated home s Normalized Modified End Use Loads relative to HERS-reference home - HERS-reference home is same size as rated home and built to 2004-IECC Every integer on scale represents 1 % change in Normalized Modified End Use Loads relative to HERS-reference home Lower numbers on scale indicate lower Normalized Modified End Use Loads than the HERS-reference home 22
Rating Scales Comparison: Inputs Input Home Energy Score HERS Site Year built Number of bedrooms Stories above ground Interior floor to ceiling height Conditioned floor area Orientation Same inputs Enclosure Air leakage rate 1 Roof construction and surface absorptance Attic or ceiling type; insulation level Foundation type, insulation level Floor insulation level Wall construction type; insulation level; exterior finish Window area 3 Skylight area 3 Window/Skylight 3 : Type or U-Value, SHGC Same inputs with following addition: Rim joist insulation Entry door type, insulation Systems Heating system type, fuel, efficiency 1 Cooling system type, fuel, efficiency 1 Duct location, insulation level 2, leakage 2 Piping insulation level Hot water heater type, fuel, energy factor 1 Mechanical ventilation not considered Renewable energy systems not considered Same inputs with following additions: Hot water heater tank insulation level Piping insulation level Duct insulation level, leakage measurement Thermostat type Mechanical ventilation type, efficiency, hours per day Passive/active renewable energy system type, size, orientation, tilt, efficiency 1 Input value is either measured or estimated based on age. 2 Default values set via Yes / No questions regarding duct insulation and leakage. 3 Some window properties are automatically set for the HERS-reference home: Total Glazing Area, Orientation of windows, Shading coefficients 23
Rating Scales Comparison: Assumptions Assumptions Home Energy Score HERS Occupancy Assumed Occupants = Two (2) adults + one (1) child Assumed Occupants = Number of bedrooms+ one (1) Interior Window & Skylight Shading Hot Water Use Shading coefficient : Assumed based on window SHGC Assumed daily hot water use based on number and ages of occupants and number of appliances Shading coefficient: Assumed based on seasonal value Assumed daily hot water use based on number of bedrooms Wall Area Assumed aspect ratio: Length : Width = 5 : 3 No assumption (observed) Thermostat Appliances Lighting Ceiling Fans Type: Assumed standard (non-programmable) thermostat Set Points 1 : Assumed Heating = 66 F ; Cooling =79 F Annual consumption: Assumed based on age and historical sales-weighted energy efficiency data Fuel type: Assumed if heating and water-heating fuels are electric, then stove, oven, and clothes drying fuels are electric Consumption : Assumed Presence: Assumed Quantity: Assumed Two (2) Type: No assumption (observed) Set points 1 : Assumed Heating = 68 F ; Cooling =78 F Annual Consumption: Assumed or Observed for refrigerator and dishwasher. Assumed for others. Fuel Type: No assumption (observed) Consumption : Assumed, adjusted based on observed percentage of high-efficacy lighting Presence: No assumption (observed) Quantity: Assumed Three (3), if present 1 Thermostat set points are the hourly weighted average. 24
Rating Scales Comparison: Overview 1. Define Three Prototype Homes; Five Climates 2. Input Prototype Homes into Rating Tools RESNET-Qualified Rating Tool 1 Home Energy Scoring Tool 2 3. Compare Results with Goal of Process Improvement Out of the Box: How do Results Compare? 1 REM/Rate version 12.91 2 Home Energy Scoring Tool pilot version 25
Rating Scales Comparison: Home Prototype Definitions Prototype homes are designed to 2012-IECC, 2006-IECC,and Existing (1970s-era) for each climate zone Climate Zone HES IECC Chicago, IL 3 5 Atlanta, GA 8 3 Houston, TX 13 2 Phoenix, AZ 17 2 Seattle, WA 18 4c HES Climate Map 26
Rating Scales Comparison: Input Alignment Out-of-box comparison of Home Energy Score and HERS Differences in inputs and assumptions for Home Energy Score and HERS affect outcome Inputs are aligned to extent possible: Inputs Home Energy Score HERS Floor Area, Number of Stories, Foundation Type Inputs Aligned Inputs Aligned Air Leakage Rate Inputs Aligned Inputs Aligned Foundation, Wall & Roof Properties (Type & R-Value) Inputs Aligned Inputs Aligned Window Properties (Area, Orientation, Type, U-Value & SHGC) Inputs Aligned Inputs Aligned Heating, Cooling, Hot Water Systems (Type, Fuel & Efficiency) Inputs Aligned Inputs Aligned Occupancy Inputs Not Aligned Inputs Not Aligned Thermostat Set Points (Heating, Cooling & Schedule) Inputs Not Aligned Inputs Not Aligned Ducts and Pipes (Location, Insulation & Leakage) Inputs Not Aligned Inputs Not Aligned 27
Home Energy Score Home Energy Score Home Energy Score Results 1970s Prototype 2012-IECC Prototype 10 10 9 9 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 0 Atlanta1970 Chicago1970 Phoenix1970 Seattle1970 Houston1970 Atlanta2012 Chicago2012 Phoenix2012 Seattle2012 Houston2012 0 Climate Home Energy Score clearly distinguishes between new and existing homes 28
HERS Index HERS Index HERS Results 1970s Prototype 2012-IECC Prototype 250 250 200 200 150 150 100 100 50 50 0 Atlanta1970 Chicago1970 Phoenix1970 Seattle1970 Houston1970 Climate Atlanta2012 Chicago2012 Phoenix2012 Seattle2012 Houston2012 0 HERS clearly distinguishes between new and existing homes 29
Home Energy Scoring Tool Predicted Source Energy [MMBtu/yr] Source Energy Comparison KEY Climate Prototype Graph Symbol 2012IECC Atlanta 2006IECC O Existing (1970s era) 2012IECC Chicago 2006IECC O Existing (1970s era) 2012IECC Houston 2006IECC O Existing (1970s era) 2012IECC Phoenix 2006IECC O Existing (1970s era) 2012IECC Seattle 2006IECC O Existing (1970s era) 500 400 300 200 100 0 Perfect Agreement 0 100 200 300 400 500 REM/Rate Predicted Source Energy[MMBtu/yr] Symbol Prototype Older homes demonstrate largest percent difference in source energy use Identical source energy factors are used Average % Difference (All Climates) Standard Deviation [MMBtu] Existing (1970s era) 15% 44 O 2006-IECC 7% 20 2012-IECC 5% 7 30
Defining Whole House Performance Targets NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.
Schedule Existing Homes Source Energy Savings** Current best in class (15% or above) Mixed/Hot-Dry and Marine Mixed-Humid and Hot-Humid Cold (Includes Cold, Very Cold, and Subarctic) 2011 2011 2011 30% 2012 2013 2014 50% 2015 2016 2017 New Homes Source Energy Savings** Current best in class (20% or above) Mixed/Hot-Dry and Marine Mixed-Humid and Hot-Humid Cold (Includes Cold, Very Cold, and Subarctic) 2010 2011 2011 30% 2011 2012 2013 50% 2014 2015 2016 ** Whole House Source Energy Savings Relative to 2009 IECC 32
BA Program Organization Cross-Cutting, Self Directed Project Teams** Pathways Analysis BA Industry Consortia Test House & Pilot Community Field Studies Multi-Lab Collaborations Audit/Rating Tool BBIS and National Assessment & Advanced Systems Measures Improvement Evaluations Database DOE Residential Initiatives Support: Better Buildings ** POC and Project Decision Authority at Working Level
Evaluating Savings Potential Annualized Total Annual Energy Costs Related ($/year) Costs, $ 2,500 2,000 cash Total flow Homeowner Cost mortgage Annual Financing Cost utility Annual bills Utility Bill 4 Least Cost Curve 1,500 1 Cost Effective Savings Potential 3 1,000 500 X Current Retrofit Program Savings 2 X Building America R&D will Triple Cost-Effective Retrofit Savings 0 0% 100% Reference Building Annual Energy Source Savings Energy (%) Savings
Example: Residential Technology Pathway Annualized Total Annual Energy Costs Related ($/year) Costs, $ 2,500 cash flow 4 Technology Pathway: Current Systems 2,000 mortgage utility bills 1,500 1,000 Current Minimum Cost Point 1 2 3 500 0 0% 100% Reference Building Annual Energy Source Savings Energy (%) Savings Incremental, Energy Related Financing & Replacement Costs
Efficiency Success Annualized Total Annual Energy Costs Related ($/year) Costs, $ 2,500 cash flow 4 Current Building Practices 2,000 mortgage utility bills 1,500 1,000 500 Current Minimum Cost Point 1 2 3 Improved Efficiency Packages: Reduces Costs And Increases Savings 0 0% 100% Reference Building Annual Energy Source Savings Energy (%) Savings
Efficiency Failure Annualized Total Annual Energy Costs Related ($/year) Costs, $ 2,500 cash flow 4 Technology Pathway: Current Systems 2,000 1,500 1 mortgage utility bills Current Minimum Cost Point 3 Efficiency Failure: Increases Costs and Reduces Savings 1,000 2 500 0 0% 100% Reference Building Annual Energy Source Savings Energy (%) Savings
Appendix BA Least Cost Energy Saving Measure Packages (ESMP) 38
BEopt Least Cost Pathway Analysis Assumptions Existing Homes New Construction Building: Vintage 1960s 2010 Geometry 1280 sqft, 1 Story, 3 Beds, 2 Baths 2500 sqft, 2 Stories w/garage, 3 Beds, 2 Baths Orientation West-facing West-facing Neighbors At 15ft At 15ft Eaves 2ft 2ft Window Area 15% of wall area (170 sqft) 15% of wall area (350 sqft) Window Distribution Front/Back/Left/Right = 20/40/20/20% Front/Back/Left/Right = 20/40/20/20% Heating/Cooling Set Points 71F/76F 71F/76F Economics: Analysis Period 30 years 30 years Inflation/Real Discount Rate 3%/3% 3%/3% Loan Period, Interest Rate 15 years, 7% 30 years, 7% Chicago Seattle Atlanta Phoenix Los Angeles Houston Utility Rates: Electricity Rate (c/kwh) 11.5 7.1 8.9 10.0 12.5 11.6 Natural Gas Rate ($/Therm) 1.08 1.22 1.18 1.31 0.72 1.07
Existing Homes
Pre-Retrofit Reference Buildings Existing Homes Walls R R0 Chicago Seattle Atlanta Phoenix Los Angeles Houston Attic R R19 R11 Foundation Windows Type R U SHGC Bsmnt R0 0.87 0.62 Infiltration SLA x 10 6 90 Crawl Slab Mech. Vent. Type Spot Vent Fridge Std or ES Old->Std* Dishwasher Std or ES Std Clothes Washer Std or ES Std Lighting % Fluor. 20% AC SEER 10->13* Furnace AFUE 80% Ducts Water Heater HW Distribution Location R, Leak% Type EF R Bsmnt R0, 30% Tank 0.59 R0 PV kw 0 Crawl Options are displayed when different than previous column. * Upgrade at wear-out. Attic
Cost/Performance Existing Homes
ESMP Existing Homes Chicago 30% 50% Seattle 30% 50% Atlanta 30% 50% Phoenix 30% 50% Los Angeles 30% 50% Walls R R13 R13 R13 R13 R13 R13 Houston 30% 50% Attic R R49 R60 R38 R49 R60 R38 R38 Foundation Windows Type R 4ft, R10 R5 R15 R5 R15 U 0.30 0.33 0.29 SHGC 0.42 0.51 0.27 Infiltration SLA x 10 6 70 50 70 70 70 70 Fridge Std or ES ES ES ES ES 0.29 0.27 0.29 0.27 Dishwasher Std or ES Clothes Washer Std or ES ES ES ES ES ES ES Lighting % Fluor. 60% 60% 60% 60% 60% 60% AC SEER Furnace AFUE 92.5% 92.5% Ducts Water Heater Location R, Leak% R6, 15% R6, 15% R6, 15% R6, 15% Type Tankless Tankless Tankless Tankless Tankless Tankless Tankless EF 0.82 0.82 0.82 0.96 0.82 0.82 0.96 PV kw 1.38 0.48 30% options displayed when different than Pre-Retrofit reference building. 50% options displayed when different than 30%. Tankless 0.96
New Construction
B10 Reference Buildings -- New Construction Chicago Seattle Atlanta Phoenix Los Angeles Houston Walls R + in. foam R13+1 R13 Attic R R38 R30 Foundation Windows Type R U SHGC Bsmt 8ft, R10 0.35 0.35 Infiltration SLA x 10 6 36 Crawl R10 R5 0.40 0.30 Slab R0 Fridge Std or ES Std Dishwasher Std or ES Std Clothes Washer Std or ES Std Lighting % Fluor. 34% AC SEER 13 Furnace AFUE 78% Ducts Water Heater Location R, Leak% Type EF Bsmnt R0, 15% Tank 0.59 Solar HW sqft 0 PV kw 0 Crawl Attic R8, 15% Options are displayed when different than previous column.
Cost/Performance -- New Construction
ESMP-- New Construction Chicago 30% 50% Seattle 30% 50% Atlanta 30% 50% Phoenix 30% 50% Los Angeles 30% 50% Houston 30% 50% Walls R + in. foam R19+2 R19+2 R19+2 R19 R19+2 R19 R19 R19+2 Attic R R60 R49 R60 R49 R49 R49 Foundation Windows Type R 8ft, R15 R15 R10 2ft R5 2ft R5 U 0.29 0.20 0.29 0.20 0.29 0.29 0.29 0.30 0.29 SHGC 0.30 0.32 0.30 0.32 0.27 0.30 0.27 0.42 0.27 Infiltration SLA x 10 6 18 8 18 Fridge Std or ES ES ES ES ES ES ES Dishwasher Std or ES ES ES ES ES ES ES Clothes Washer Std or ES ES ES ES ES ES ES Lighting % Fluor. 100% 100% 100% 100% 100% 100% AC SEER 17 15 15 17 17 17 18 Furnace AFUE 92.5% 92.5% 92.5% 92.5% Ducts Water Heater Solar HW Location R, Leak% Type EF sqft Inside Inside Inside Inside Inside Inside Tankless 0.82 Tankless 0.96 Tankless 0.96 Tankless 0.82 Tankless 0.96 Tankless 0.82 Tankless 0.82 Tankless 0.82 PV kw 1.34 2.17 1.99 1.55 0.30 1.91 1.95 30% options displayed when different than B10 reference building. 50% options displayed when different than 30%.
What s Next? Determination of Cost and Performance Targets for Emerging Technologies NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. 48
Cold Climate (Chicago), New Construction Non-Competitive Efficiency Measures PV Starting Point 49
Cold Climate (Chicago), Existing Home Non-Competitive Efficiency Measures PV Starting Point 50
Hot Climate (Phoenix), New Construction Non-Competitive Efficiency Measures PV Starting Point 51
Hot Climate (Phoenix), Existing Home Non-Competitive Efficiency Measures PV Starting Point 52
Background The residential integration research program has developed a cost/performance optimization tool (BEopt) to determine the incremental benefits of energy efficiency technologies as a function of climate and total whole house savings levels The tool prioritizes efficiency measures based on cost and performance including whole building interactions (i.e. reduced internal loads increase heating loads in cold climates ) 53
Background (continued) The tool is supported by public datasets including a National Measures Database which provides reference efficiency measure costs and characteristics, and a Residential Data Repository which provides well characterized field datasets for validation studies. The tool is also supported by software accuracy research which includes development of standard software methods of test and development of methods to compare and correct individual algorithms within energy simulation engines. 54
Determining ET Cost and Performance Targets The BEopt tool defines a technology pathway that can be used to determine if a new technology: -Provides cost or performance savings relative to current technologies, or -Extends achievable savings beyond what can be achieved with existing technologies. The tool can also be used to set cost and performance targets that must be met for a new technology to successfully compete with existing solutions. 55
Example: Benefits of Advanced Wood Stud As an example, BEopt will be used to evaluate the benefits of an advanced 2x6 stud composed of a 2x4 laminated to a 1.5 x1.5 rigid foam thermal break and a 1.5 x7/16 interior nailer. 5.5 How does this advanced stud with R-19 cavity insulation compare to other high R wall options? 56
Results: Advanced Wood Stud Annualized Energy Related Costs ($/yr) 3000 2800 2x4 R13 2x6 R19 Minneapolis, Minnesota - - - - - 2x4, R13 + 2 foam - - - - - - - Technology Pathway: Current Systems 2600 2400 EW@$3.40/ft2 EW@$3.90/ft2 EW@$4.40/ft2 Best Conventional 2200 2000 1800 1600 0 10 20 30 40 50 60 Source Energy Savings (%) 57
Results: Advanced Wood Stud Annualized Energy Related Costs ($/yr) 3000 2800 2600 2x4 R13 2x6 R19 Minneapolis, Minnesota - - - - - 2x4, R13 + 2 foam - - - - - - - Advanced Stud, R19 Performance Curves Advanced Wall Cost EW@$3.40/ft2 EW@$3.90/ft2 2400 EW@$4.40/ft2 Best Conventional 2200 2000 1800 1600 0 10 20 30 40 50 60 Source Energy Savings (%) 58
Results: Advanced Wood Stud Annualized Energy Related Costs ($/yr) Break-Even Cost for Enviro-Wall Framing ($/ft) Minneapolis, Minnesota 3000 1.50 2800 2x4 R13 2x6 R19 - - - - - 2x4, R13 + 2 foam - - - - - - - 1.40 1.30 2600 2400 1.20 1.10 1.00 EW@$3.40/ft2 EW@$3.90/ft2 EW@$4.40/ft2 Best Conventional Break-Even Cost 2200 2000 1800 1600 Advanced Framing Break-Even Cost Materials Cost = $0.46/ft * 0.90 0.80 0.70 0.60 0.50 0.40 * Material Costs: ($/ft ) 2x4 0.33 XPS, 1.5 in 0.09 OSB, 7/16 in 0.04 TOTAL 0.46 Per RSMeans 2010 0 10 20 30 40 50 60 Source Energy Savings (%) 59
Advanced Wood Stud Results (Continued) Annualized Energy Related Costs ($/yr) Break-Even Cost for Enviro-Wall Framing ($/ft) Minneapolis, Minnesota 3000 1.50 2800 2600 2400 2x4 R13 2x6 R19 - - - - - 2x4, R13 + 2 foam - - - - - - - Potential benefit at lower savings levels 1.40 1.30 1.20 1.10 1.00 EW@$3.40/ft2 EW@$3.90/ft2 EW@$4.40/ft2 Best Conventional Break-Even Cost 2200 2000 1800 1600 0 10 20 30 40 50 60 Source Energy Savings (%) Materials Cost = $0.46/ft * 0.90 0.80 0.70 0.60 0.50 0.40 * Material Costs: ($/ft ) 2x4 0.33 XPS, 1.5 in 0.09 OSB, 7/16 in 0.04 TOTAL 0.46 Per RSMeans 2010 60
Advanced Wood Stud Results (Continued) Annualized Energy Related Costs ($/yr) Break-Even Cost for Enviro-Wall Framing ($/ft) Minneapolis, Minnesota 3000 1.50 2800 2600 2400 2x4 R13 2x6 R19 - - - - - 2x4, R13 + 2 foam - - - - - - - Can t compete at optimal savings levels 1.40 1.30 1.20 1.10 1.00 EW@$3.40/ft2 EW@$3.90/ft2 EW@$4.40/ft2 Best Conventional Break-Even Cost 2200 2000 1800 1600 0 10 20 30 40 50 60 Source Energy Savings (%) Materials Cost = $0.46/ft * 0.90 0.80 0.70 0.60 0.50 0.40 * Material Costs: ($/ft ) 2x4 0.33 XPS, 1.5 in 0.09 OSB, 7/16 in 0.04 TOTAL 0.46 Per RSMeans 2010 61
Advanced Wood Stud Results (Continued) Annualized Energy Related Costs ($/yr) Break-Even Cost for Enviro-Wall Framing ($/ft) Minneapolis, Minnesota 3000 1.50 2800 2600 2400 2x4 R13 2x6 R19 - - - - - 2x4, R13 + 2 foam - - - - - - - Can t compete at higher savings levels 1.40 1.30 1.20 1.10 1.00 EW@$3.40/ft2 EW@$3.90/ft2 EW@$4.40/ft2 Best Conventional Break-Even Cost 2200 2000 1800 1600 0 10 20 30 40 50 60 Source Energy Savings (%) Materials Cost = $0.46/ft * 0.90 0.80 0.70 0.60 0.50 0.40 * Material Costs: ($/ft ) 2x4 0.33 XPS, 1.5 in 0.09 OSB, 7/16 in 0.04 TOTAL 0.46 Per RSMeans 2010 62
Advanced Wood Stud Results (Continued) Annualized Energy Related Costs ($/yr) Break-Even Cost for Enviro-Wall Framing ($/ft) Minneapolis, Minnesota 3000 1.50 2800 2600 2400 2x4 R13 2x6 R19 - - - - - 2x4, R13 + 2 foam - - - - - - - Cannot fill efficiency gap 1.40 1.30 1.20 1.10 1.00 EW@$3.40/ft2 EW@$3.90/ft2 EW@$4.40/ft2 Best Conventional Break-Even Cost 2200 2000 1800 1600 0 10 20 30 40 50 60 Source Energy Savings (%) Materials Cost = $0.46/ft * 0.90 0.80 0.70 0.60 0.50 0.40 * Material Costs: ($/ft ) 2x4 0.33 XPS, 1.5 in 0.09 OSB, 7/16 in 0.04 TOTAL 0.46 Per RSMeans 2010 63
Advanced Wood Stud Results (Continued) Annualized Energy Related Costs ($/yr) Break-Even Cost for Enviro-Wall Framing ($/ft) Minneapolis, Minnesota 3000 1.50 2800 2600 2400 2x4 R13 2x6 R19 - - - - - 2x4, R13 + 2 foam - - - - - - - Breakeven cost for advanced stud over its competitive range is $0.65/ft-$0.85/ft 1.40 1.30 1.20 1.10 1.00 EW@$3.40/ft2 EW@$3.90/ft2 EW@$4.40/ft2 Best Conventional Break-Even Cost 2200 2000 1800 1600 0 10 20 30 40 50 60 Source Energy Savings (%) Materials Cost = $0.46/ft * 0.90 0.80 0.70 0.60 0.50 0.40 * Material Costs: ($/ft ) 2x4 0.33 XPS, 1.5 in 0.09 OSB, 7/16 in 0.04 TOTAL 0.46 Per RSMeans 2010 64
Mixed Climate Results Annualized Energy Related Costs ($/yr) Break-Even Cost for Enviro-Wall Framing ($/ft) Washington, DC 2600 1.50 2400 2200 2x4 R13 2x6 R19 - - - 2x4, R13 + 2 foam - - - - - - Washington DC, potential benefit at optimal savings levels 1.40 1.30 1.20 1.10 EW@$3.40/ft2 EW@$3.90/ft2 EW@$4.40/ft2 2000 1800 1.00 0.90 Best Conventional Break-Even Cost 0.80 1600 1400 Materials Cost = $0.46/ft * 0.70 0.60 0.50 * Material Costs: ($/ft ) 2x4 0.33 XPS, 1.5 in 0.09 OSB, 7/16 in 0.04 TOTAL 0.46 1200 0.40 Per RSMeans 2010 0 10 20 30 40 50 60 Source Energy Savings (%) 65
Mixed Climate Results (continued) Annualized Energy Related Costs ($/yr) Break-Even Cost for Enviro-Wall Framing ($/ft) Washington, DC 2600 1.50 2400 2200 2x4 R13 2x6 R19 - - - 2x4, R13 + 2 foam - - - - - - Cannot fill efficiency gap 1.40 1.30 1.20 1.10 EW@$3.40/ft2 EW@$3.90/ft2 EW@$4.40/ft2 2000 1800 1.00 0.90 Best Conventional Break-Even Cost 0.80 1600 1400 Materials Cost = $0.46/ft * 0.70 0.60 0.50 * Material Costs: ($/ft ) 2x4 0.33 XPS, 1.5 in 0.09 OSB, 7/16 in 0.04 TOTAL 0.46 1200 0.40 Per RSMeans 2010 0 10 20 30 40 50 60 Source Energy Savings (%) 66
Mixed Climate Results (continued) Annualized Energy Related Costs ($/yr) Break-Even Cost for Enviro-Wall Framing ($/ft) Washington, DC 2600 1.50 2400 2200 2x4 R13 2x6 R19 - - - 2x4, R13 + 2 foam - - - - - - Breakeven cost for advanced stud over its competitive range is $0.60/ft-$0.75/ft 1.40 1.30 1.20 1.10 EW@$3.40/ft2 EW@$3.90/ft2 EW@$4.40/ft2 2000 1800 1.00 0.90 Best Conventional Break-Even Cost 0.80 1600 1400 Materials Cost = $0.46/ft * 0.70 0.60 0.50 * Material Costs: ($/ft ) 2x4 0.33 XPS, 1.5 in 0.09 OSB, 7/16 in 0.04 TOTAL 0.46 1200 0.40 Per RSMeans 2010 0 10 20 30 40 50 60 Source Energy Savings (%) 67
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NREL Research on Low Carbon Homes and Communities: Cost Effective Integration of Efficiency and Renewables NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. 71
Carbon Analysis Control Volume ZEH Control Volume Home or Neighborhood 1 site 1 site Source Energy and Emission Factors for Energy Use in Buildings, M. Deru and P. Torcellini, NREL/TP-550-38617, June, 2007.
Zero Energy Home Goals Key Near Term Performance Indicators Reduction in HVAC Capacity 100% 100% Critical Peak Demand 50 50 0 2010 2015 2020 CO 2 Emissions Reduction 100% 0 2010 2015 2020 Incremental Home Operating Cost +15% 50 0 0 2010 2015 2020-15% 2010 2015 2020
Key ZEH Element: High R Enclosure Photo courtesy Building Science Corporation 74
Key ZEH Element: Max Tech Equipment
Key ZEH Element: Site Renewable Energy
Key Control Element: Plug and Play Home Energy Management
Envelope Wall Insulation Ceiling Insulation Garage Ceiling Roofing Material Radiant Barrier Infiltration Foundation Slab Basement Crawl Space Thermal Mass Exposed Floor Ceiling Mass Wall Mass Windows & Shading Window Areas Window Type Eaves Lg. Appliances Refrigerator Cooking Range Dishwasher Clothes Dryer Clothes Washer Lighting Hardwired Lighting Plug-in Lighting Equipment Air Conditioner Furnace Heat Pump echanical Ventilation Water Heater Ducts Renewables Solar DHW SDHW Azimuth SDHW Tilt PV Size PV Azimuth PV Tilt 2 9 5 4 2 1 2 2 3 1 1 1 1 2 2 1 2 1 1 2 1 2 3 3 2 9 1 9 1 10 3 7 2 3 1 2 4 6 2 4 1 2 Option Menu 7 1 8 7 13 13 Option Numbers Ref Point Current Point Available Options
Total All Energy Annual Related Costs ($/year) Costs, $ Optimization Approach: Least Cost Modeling Based on Representative Occupant Behavior 2,500 2,000 cash flow mortgage utility bills 4 Least Cost Curve, Using Current Best Available Systems 1,500 1 Minimum Cost Point 3 Neutral Cost Line 1,000 2 ZEH Systems Research Cost/Performance Target 500 0 0% 50% 100% Reference Source Energy Energy Savings Savings (%) Incremental, Energy Related Mortgage & Replacement Costs Christensen, C.; Anderson, R.; Horowitz, S.; Courtney, A.; Spencer, J. (2006). BEopt(TM) Software for Building Energy NATIONAL RENEWABLE Building ENERGY Optimization: LABORATORY Features and Capabilities. 21 pp.; NREL Report No. TP-550-39929.
Phoenix Carbon Savings Potential (metric tons/year) Add: Ducts inside + Gas Tankless Hot Water Add: R21 Wall+CFLs Add: Horizontal Axis Clothes Washer+SEER 17 AC+Estar Fridge+R50 Ceiling Add: Infiltration Package+Solar ICS Hot Water+ 1" Polyiso Sheathing EE with 1.5kW PV EE with 3.5kW PV EE with 5.5kW PV IECC 2006 Reference Hot Climate: Phoenix 0 5 10 15 20
Ave Cost per Metric Ton Hot Climate: Estimated Cost of Carbon Savings $150.00 $100.00 5.5 kw PV $50.00 3.5 kw PV $0.00 1.5 kw PV -$50.00 -$100.00 -$150.00 -$200.00 Hot Climate: Phoenix 0 2 4 6 8 10 12 14 16 Metric Tons/Year
Phoenix Utility Bill Savings ($/Year) IECC 2006 Base+ R19 Walls+R8 Ducts Add: Ducts inside + Gas Tankless Hot Water Add: R21 Wall+CFLs Add: Horizontal Axis Clothes Washer+SEER 17 AC+Estar Fridge+R50 Ceiling Add: Infiltration Package+Solar ICS Hot Water+ 1" Polyiso Sheathing EE with 1.5kW PV EE with 3.5kW PV EE with 5.5kW PV IECC 2006 Reference Phoenix, 2500 ft2 SF $0 $500 $1,000 $1,500 $2,000
Net kw July Demand Profile in Phoenix 6.5 5.5 4.5 Reduction in Critical Summer Peak 3.5 2.5 IECC 2006 Max EE+3.5kW 1.5 0.5-0.5-1.5 0 4 8 12 16 20 24 Hour Phoenix, 2500 ft 2, SF
Probability (%) Probability (%) Annual Distribution of ZEH Demand IECC 2006 Max EE + 3.5 kw PV -5-4 -3-2 -1 0 1 2 3 4 5 Net Electric Use (kw) Phoenix, 2500 ft 2, SF
Full Year (8760 hr) Demand Profile IECC 2006 Max EE+ 3.5 kw PV Phoenix, 2500 ft 2, SF
Net kw January Demand Profile in Phoenix 6.5 January Demand Profile in Phoenix 5.5 4.5 3.5 2.5 1.5 0 IECC 2006 Max EE+3.5kW 0.5-0.5 Net Site PV Generation -1.5 0 4 8 12 16 20 24 Hour Phoenix, 2500 ft 2, SF
Electric Demand Contributions of Daily Demand to Utility Load Duration Curve Peak Load Intermediate Load Base Load Time (hr) Daily Load Curve Base Load Duration (hours) Load Duration Curve
Load (MW) Annual Load Duration Curve 15000 Peak Load 10000 5000 Intermediate Load Base Load (Coal) 0 0 2000 4000 6000 8000 Hours Phoenix 2012, Reliability Must-Run Analysis, January 31, 2004, p.33, APS Transmission Planning
Grid Integration and Energy Management with Large ZEH Penetration Net Site PV Generation Peak Load Net Generation Intermediate Load 0 Daily Base Load without PV 0 Base Load Daily Load Curve Load Duration Curve
ZEH Demand Duration Curves Reduced Peak Load IECC 2006 Max EE + 3.5 kw PV Reduced Base Load from Site Generation Off Peak Variable Generation Reduced Base Load From Efficiency Phoenix, 2500 ft 2, SF
Contact Information Dr. Ren Anderson NREL Residential Research www.buildingamerica.gov ren.anderson@nrel.gov