Statewide Electricity and Demand Capacity Savings from the Implementation of IECC Code in Texas: Analysis for Single-Family Residences

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1 ESL-IC Statewide Electricity and Demand Capacity Savings from the Implementation of Code in Texas: Analysis for Single-Family Residences Hyojin Kim Juan-Carlos Baltazar Jeff S. Haberl Research Associate Assc. Research Engineer Professor/Assc. Director Cynthia Lewis TERP Manager Bahman Yazdani, P.E. Assc. Director Energy Systems Laboratory, Texas A&M University System, College Station, TX. ABSTRACT This paper presents estimates of the statewide electricity and electric demand savings achieved from the adoption of the International Energy Conservation Code () for single-family residences in Texas and includes the corresponding increase in construction costs over the eight-year period from through 9. Using the Energy Systems Laboratory s International Code Compliance Calculator (IC3) simulation tool, the annual statewide electricity savings in 9 are estimated to be $11 million. The statewide peak electric demand reductions in 9 are estimated to be 9 MW for the summer and 7 MW for the winter periods. Since, the cumulative statewide electricity and electric demand savings over the eight year period from to 9 are $1,3 million ($77 million from electricity savings and $1,7 million from electric demand savings) while the total increased costs are estimated to be $7 million. INTRODUCTION In September 1, Texas adopted the International Energy Conservation Code (), including the 1 Supplement as the first statewide energy code. During this period, several improved versions of have been published and adopted by individual jurisdictions. The analysis shows the building energy code has substantially improved the energy efficiency of housing in Texas, resulting in reduced annual heating/cooling, which is reflected in the reduced utility bills for residential customers. This paper presents an analysis of the statewide electricity and electric demand savings achieved from the adoption of the different versions for single-family residences in Texas, including the corresponding construction cost increases over the eight-year period from through 9. METHODOLOGY The analysis consists of two parts: a buildinglevel analysis and a state-level analysis. Building-Level Analysis At the building-level analysis, the energy savings and peak demand reductions per house were calculated using the IC3 simulation program (BDL version.1.7 of IC3), which is based on the DOE-.1e simulation program and the appropriate TMY weather files for the corresponding location. To perform the analysis, counties in Texas representing three Climate Zones across Texas were selected: for Climate Zone, for Climate Zone 3, and for Climate Zone (Figure 1). For each representative county, a total of six simulations that represent precode 1999 conditions and code-compliant conditions meeting the requirements of the 1 and the were simulated for the appropriate periods: three runs for (a) an electric/gas house (i.e., a gas-fired furnace for space heating, and a gas-fired water heater for domestic water heating) and the next three runs for (b) a heat pump house 1 (i.e., a house with a heat pump for space heating, and electric Figure 1. Climate Zone Classification and Three Selected Counties in Texas 1 To estimate the heating savings, heat pump systems were selected for space heating of all-electric houses instead of electricresistance heaters. 1 Proceedings of the Eleventh International Conference Enhanced Building Operations, New York City, October 1-, 11

2 ESL-IC water heater for domestic water heating). Using these models, the energy savings and peak demand reductions per house compared to the pre-code building were calculated for each climate zone. State-Level Analysis At the state-level analysis, two different approaches were applied to calculate the statewide annual electricity and electric demand savings associated with the codes adoption in Texas. To calculate the statewide electricity savings, the annual MWh savings from code-compliant, new single-family housing in Texas for years through 9 reported in the Laboratory s Annual Reports submitted to the Texas Commission on Environmental Quality (TCEQ) were used (Haberl et al. -1). For the years through, the annual electricity savings (MWh/year) were calculated for the 1 non-attainment and affected counties. From to 9, the savings were calculated for all the counties in Electric Reliability Council of Texas (ERCOT) region, which includes the 1 non-attainment and affected counties. These annual electricity savings were then multiplied by the annual average electric prices in Texas published by the US DOE EIA (11) shown in Figure. To compute the statewide electric demand savings (i.e., avoided construction cost of a peaking plant), the peak demand reductions per house calculated in the building-level analysis were multiplied by the number of new single-family houses built in each climate zone of each year (RECenter 11) and aggregated to annual totals using an annual degradation factor of %. Figure shows the building permits per year for new singlefamily residences in Texas by climate zone as well as the average statewide electricity price ( /kwh). The ratio of electric/gas and heat pump houses constructed in Texas was determined using the annual surveys, National Association of Home Builders (NAHB) (NAHB 1 and 9-1). Figure 3 shows the ratio of the single family residences in Texas by type of heating system for Climate Zone (CZ ) and for Climate Zones 3 and (CZ 3& combined). The 1 and were assumed to be adopted across Texas in and 7, respectively in the analysis. A % initial discount factor and a 7% transmission and distribution loss factor were applied to the calculations. To estimate electric demand savings, the calculated statewide electric demand savings (MW) Number of New Single-Family Houses 1, 1, 1, 1, 1,,,,, Figure. Number of Building Permits for New Single-Family Construction in Texas by Climate Zone and Annual Average Price of Electricity for Residential Customers in Texas Type of Heating System (%) 1% 9% % 7% % % % 3% % 1% % Climate Zone Climate Zone 3 Climate Zone Elec. Price ( /kwh) Gas_CZ Electric_CZ Gas_CZ3 & Electric_CZ3 & Figure 3. Type of Heating System of New Single-Family Construction in Texas Proceedings of the Eleventh International Conference Enhanced Building Operations, New York City, October 1-, Average Electricity Price ( /kwh)

3 ESL-IC were then multiplied by the average capital cost of a natural gas combined cycle power plant, $1,1 per kw (Kaplan, ) using a 1% reserve margin (Faruqui et al. 7). Incremental Cost Analysis Finally, an incremental cost analysis was conducted to determine if the savings are sufficient to justify the increased construction costs for upgrading to the. The increased costs for upgrading major residential building components and systems to comply with the 1 and the were examined using R.S. Means Residential Cost Data (R. S. Means and 7), the Building Codes Assistance Project (BCAP) Incremental Construction Cost Analysis for New Homes (Paquette et al. 1), the American Council for an Energy-Efficient Economy (ACEEE) Consumer Guide to Home Energy Savings (Amann et al. 7), and the similar incremental cost analysis studies in Texas (Malhotra et al. ; Kim et al. 1). The construction characteristics published by the NAHB () were used to define pre-code house conditions. The calculated per-house costs of implementation of the were then multiplied by the number of new single-family houses in the ERCOT region (1 nonattainment and affected counties from to and all the counties in the ERCOT region from to 9) and aggregated to cumulative total increased costs over the eight year period from to 9. The 1 and were assumed to be adopted across Texas in and 7 for new single-family residences, respectively. BASE-CASE BUILDING DESCRIPTION The base-case building used for a simulation in the building-level analysis is a,3 sq. ft., squareshape, one story, single-family, detached house with a floor-to-ceiling height of feet. The house has an attic with a roof pitched at 3 degrees. The wall construction is light-weight wood frame with x studs at 1 on center with a slab-on-grade-floor, which is typical construction according to the NAHB survey (NAHB 3). The pre-code building envelope and system characteristics were determined based on the construction characteristics published by the NAHB () for typical residential construction in East and West Texas for The code-compliant building envelope and system characteristics were determined from the general characteristics and the climate-specific characteristics as specified in the 1 and the. Table 1 summarizes the base-case building characteristics used in the simulation model for each climate zone. To facilitate a more accurate and realistic comparison between the codes, several modifications were applied to the simulations as follows. For the 1 simulation, internal heat gains and interior shading fractions for winter were adjusted to match the values required in the : internal heat gains:.7 kw/house for lighting and.7 kw/house for equipment; and interior shading fraction for winter:.. For all simulations, the thermostat set points were also modified to match the 9 specifications of 7 F for heating and 7 F for cooling with no set-back/set-up schedule as a more realistic estimate of savings 3. ENERGY SAVINGS AND ELECTRIC DEMAND REDUCTIONS PER HOUSE Table summarizes the results of the energy savings analysis for,, and Counties, including: the annual total site energy consumption (MMBtu/year and $/year by total and fuel types), as well as energy savings associated with the code adoption. Table 3 presents summer and winter peak electric demand and reductions expected from 1 and adoption. The results are also graphically represented in Figure through Figure. Annual Per-House Energy Consumption Across all counties, the pre-code houses reported the highest consumption with a total of: (a) an electric/gas house: 1. MMBtu/year for, MMBtu/year for, and MMBtu/year for and (b) a heat pump house: 93.1 MMBtu/year for, 9.7 MMBtu/year for, and 113. MMBtu/year for. Conversely, the code-compliant house reported the lowest site energy consumption with a total of: (a) an electric/gas house: 1. MMBtu/year for, 11. MMBtu/year for, and 1.9 MMBtu/year for and (b) a heat pump house: 7.7 MMBtu/year for, 79. MMBtu/year for, and 7. MMBtu/year for. Similar trends were observed in the estimated annual utility bill of a house using $.11/kWh for electricity (PUCT 1) and $./therm for natural gas (Climate Zone ) and $./therm for natural gas (Climate Zone 3 and ) for natural gas (CPS Energy 1, Atmos Energy 1a and 1b). Across the counties, the pre-code houses are expected to have These unifying modifications to the simulation inputs were necessary because the comparisons between the pre-code, 1 and simulations could not be performed if different values were used. 3 Although the results of the 9 simulations are not reported in this report, ongoing work identified these changes to the simulation inputs. 3 Proceedings of the Eleventh International Conference Enhanced Building Operations, New York City, October 1-, 11

4 ESL-IC Table 1. Base Case Building Description Building Building Type Gross Area Number of Floors Floor to Floor Height (ft.) Orientation Construction Construction Floor Roof Configuration Roof Absorptance Ceiling Insulation (hr-sq.ft.- F/Btu) 1 Wall Absorptance Wall Insulation (hr-sq.ft.- F/Btu) 1 Slab Perimeter Insulation Ground Reflectance U-Factor of Glazing (Btu/hr-sq.ft.- F) 1 Solar Heat Gain Coefficient (SHGC) 1 Window Area Interior Shading Exterior Shading Roof Radiant Barrier Slope of Roof Space Conditions Space Temperature Set point Internal Heat Gains Number of Occupants Mechanical Systems HVAC System Type Cooling Capacity (Btu/hr) Heating Capacity (Btu/hr) DHW Heater Energy Factor Duct Distribution System Efficiency Supply Air Flow (CFM/ton) Infiltration Rate (SG) Note: Characteristics CZ CZ 3 CZ CZ CZ 3 CZ CZ CZ 3 CZ HVAC System Efficiency 1 DHW System Type R-7. R F Heating, 7 F Cooling 1 The ceiling and wall insulation, glazing specifications, and HVAC system efficiencies for the pre-code houses were determined based on the NAHB Survey for typical residential construction in East and West Texas for For a fair comparison, the pre-code house was assumed to have the same floor area, ceiling height, and window areas as the 1 code-compliant house rather than following the NAHB survey results. 3 To facilitate a more accurate and realistic comparison between the codes, several adjustments were applied to the 1 and codes. SEER 1 was used to comply with the 1 performance path. :.. (Simulation adjustment 3 : Heating 7F, Cooling 7F). kw (Simulation adjustment 3 : 1.9 kw) : Electric cooling (air conditioner) and natural gas heating (gas fired furnace) Electric cooling and heating (air conditioner with heat pump) : SEER 11 AC,. AFUE SEER 11 AC,. HSPF Single family, detached house,3 sq. ft. (.1 ft. x.1 ft.) South facing Light-weight wood frame with x studs spaced at 1 on center Slab-on-grade floor Unconditioned, vented attic R (Assuming brick facia exterior) None R-. (Assuming grass) R-1.1 Sum.7 Win. 1.9 kw R-.7. None R-. Sum.7 Win.9 (Simulation adjustment 3 : Sum.7, Win.) None No :1 (= 3 degrees) F Heating, 7 F Cooling, F setback/setup : SEER 1 AC,.7 AFUE SEER 1 AC,. HSPF, (= sq. ft./ton), (= 1. x cooling capacity) : -gallon tank type gas water heater with a standing pilot light -gallon tank type electric water heater (without a pilot light). 3 R-1/3 c.i.. 1% of conditioned floor area R-7. None None (Assuming internal gains include heat gain from occupants) SLA=.7 R-11 1 R-3 R-11.. F Heating, 7 F Cooling 1.9 kw (.7 kw for lighting and.7 kw for equipment) : SEER 13 AC,.7 AFUE SEER 13 AC, 7.7 HSPF heat :.9.9 SLA=.3 R-3.1 R-1 Summer.7, Winter. Proceedings of the Eleventh International Conference Enhanced Building Operations, New York City, October 1-, 11

5 ESL-IC Table. Annual Per-House Energy Savings from Code-Compliant, Single Family Residences in Texas (CZ ) (CZ 3) (CZ) Total Elec. NG Total Elec. NG Total Elec. NG Total Elec. NG % Savings vs $,7 $,9 $ Modified $,93 $,137 $ $31 $1 $.% Modified 1... $,37 $1,3 $ $7 $ $1 17.9% $,17 $,19 $ Modified $,7 $, $ $9 $1 $.% Modified $,19 $1,1 $ $ $3 $7 1.% $,79 $1,91 $ Modified $, $, $ $111 -$113 $3.1% Modified $,1 $1,7 $9... $33 $ $9 19.9% (b) Heat Pump House (CZ ) (CZ 3) (CZ) Test Cases Annual Total Site Energy Consumption (MMBtu/year) ($/year) (MMBtu/year) Annual Total Site Energy Savings ($/year) $3,1 $3, Modified.. - $,7 $, $ $ -.1% Modified $,73 $, $9 $9-17.% $3,3 $3, Modified $,1 $, $39 $39-7.% Modified $,3 $, $ $ - 1.% $3,3 $3, Modified $3,33 $3, $313 $313 -.% Modified $, $, $3 $3-3.% Table 3. Annual Per-House Peak Electric Demand Reductions from Code-Compliant, Single Family Residences in Texas (CZ ) (CZ 3) (CZ) (CZ ) (CZ 3) (CZ) Test Cases Peak Demand 1 Summer Demand (kw) Reduction % Reduction vs. Pre- Code Peak Demand Winter Demand (kw) Reduction % Reduction vs. Pre- Code Modified...1% Modified.. 9.% Modified...% Modified % Modified 7...% Modified % (b) Heat Pump House Note: Modified.. 7.7% % Modified.1..% % Modified.7..1% % Modified % % Modified 7...% 13...% Modified. 1.9.% % 1 Summer Peak Demand Date: -September 1 (CZ ), August 13 (CZ 3), and June 9 (CZ ); and (b) Heat Pump House-September 1 (CZ ), August 13 (CZ 3), and June 9 (CZ ) Winter Peak Demand Date: (b) Heat Pump House-January 11 (CZ ), January 1(CZ 3), and January 7 (CZ ) Proceedings of the Eleventh International Conference Enhanced Building Operations, New York City, October 1-, 11

6 ESL-IC , Climate Zone 1, Climate Zone 3 1, Climate Zone 1 Electricity Use (MMBtu/mo) 1 1 Electricity Use (MMBtu/mo) 1 1 Electricity Use (MMBtu/mo) 1 1 Figure. Monthly Electricity Use for a and Code-Compliant, Electric/Gas House in Texas, Climate Zone 1, Climate Zone 3 1, Climate Zone 1 NG Use (MMBtu/mo) 1 1 NG Use (MMBtu/mo) 1 1 NG Use (MMBtu/mo) 1 1 Figure. Monthly Natural Gas Use for a and Code-Compliant, Electric/Gas House in Texas, Climate Zone (b) Heat Pump House, Climate Zone 3 (b) Heat Pump House, Climate Zone (b) Heat Pump House Electricity Use (MMBtu/mo) 1 1 Electricity Use (MMBtu/mo) 1 1 Electricity Use (MMBtu/mo) 1 1 Figure. Monthly Electricity Use for a and Code-Compliant, Heat Pump House in Texas Proceedings of the Eleventh International Conference Enhanced Building Operations, New York City, October 1-, 11

7 ESL-IC Electricity Use (kw) , Climate Zone (Sep. 1) 1 Electricity Use (kw) , Climate Zone 3 (Aug. 13) 1 Electricity Use (kw) , Climate Zone (June 9) Hour of Day Hour of Day Hour of Day Figure 7. Peak Summer Day Hourly Electricity Use for a and Code-Compliant, House in Texas Electricity Use (kw), Climate Zone (Jan. 11), Climate Zone 3 (Jan. 1), Climate Zone (Jan. 7) Hour of Day Hour of Day Hour of Day Electricity Use (kw) Figure. Peak Winter Day Hourly Electricity Use for a and Code-Compliant, Heat Pump House in Texas Electricity Use (kw) the highest energy bills: (a) an electric/gas house: $,7/year for, $,17/year for, and $,79/year for and (b) a heat pump house: $3,1/year for, $3,3/year for, and $3,3/year for. Alternatively, the code-compliant houses are expected to have the lowest energy bills: (a) an electric/gas house: $,37/year for, $,19/year for, and $,1/year for and (b) a heat pump house: $,73/year for, $,3/year for, and $,/year for. Annual Per-House Energy Savings from the Adoption of the 1 and The annual energy savings associated with the 1 and were calculated compared to the pre-code cases: (a) an electric/gas house: 1.-. MMBtu/year ($31-$7/year) for, MMBtu/year ($9-$/year) for, and MMBtu/year ($111- $33/year) for and (b) a heat pump house: MMBtu/year ($-$9/year) for, MMBtu/year ($39- $/year) for, and MMBtu/year ($313-$3/year) for. The corresponding percent savings over a pre-code house are: (a) an electric/gas house:.-17.9% for,.-1.% for, and % for and (b) a heat pump house:.1-17.% for, 7.-1.% for, and.-3.% for. For an electric/gas house, the natural gas savings (MMBtu/year) achieved from 1 is larger than electricity savings. In, the savings of all three versions of codes are mainly from the savings in natural gas rather than electricity. However, due to the difference in the unit cost of electricity and gas, the dollar savings from electricity are higher than the savings from gas, except in A negative electricity savings was expected for a 1 code-compliant, electric/gas house in due to the increased cooling energy consumption. This is because a lower SEER (SEER 1) A/C unit was used for a 1 codecompliant house simulation to comply with the 1 performance path requirement. For a pre-code house, a SEER 11 A/C unit was used from the NAHB survey results (). 7 Proceedings of the Eleventh International Conference Enhanced Building Operations, New York City, October 1-, 11

8 ESL-IC In, no electricity savings were observed from 1 code adoption. From the code adoption, the savings from gas and electricity are almost the same. Per-House Peak Electric Demand Reductions from 1 and The pre-code houses reported the highest peak summertime demand: (a) an electric/gas house:.7 kw for, 7. kw for, and 7. kw for and (b) a heat pump house: 7.1 kw for, 7.3 kw for, and 7. kw for. Not surprisingly, the code-compliant house reported the lowest peak summertime demand: (a) an electric/gas house:. kw for,.1 kw for, and.1 kw for and (b) a heat pump house:.1 kw for,. kw for, and. kw for. In the analysis, the same peak day was used regardless of the house type: September 1 for, August 13 for, and June 9 for. In the winter, the peak electric demands were estimated for a heat pump house. The peak days used in the analysis were: January 11 for, January 1 for, and January 7 for. As reported, the highest peak wintertime electric demands are for a pre-code house: 11.3 kw for, 1. kw for, and 17.9 kw for. The lowest wintertime demands for the codecompliant house are: 7.7 kw for,. kw for, and 1. kw for. Finally, the peak electric demand reductions associated with the 1 and were calculated for both summer and winter. For summer, the reductions in peak summertime electric demands are expected to happen in the afternoon between 3 to pm for both electric/gas and heat pump houses:.-. kw for,.-1.9 kw for, and 1.9 kw for. In, no demand savings are expected in summer from the 1 code adoption. For winter, the electric demand reductions were estimated to occur in early morning hours between and am for a heat pump house: kw for,.-3. kw for, and.-. kw for. The corresponding percentage summer electric demand reductions over a pre-code house are: (a) an electric/gas house:.1-9.% for,.-7.% for, and 7.1% for and (b) a heat pump house: 7.7-.% for,.1-.3% for, and.% for. In winter, the percent reductions are: (b) a heat pump house: % for, % for, and.-31.% for. INCREMENTAL COST ANALYSIS Table presents the estimated per-house increased costs for upgrading major building components and systems to comply with the 1 and the for each climate zone. The per-house increased construction costs for upgrading to the 1 are estimated to be $ for Climate Zone, $77 for Climate Zone 3, and $1,1 for Climate Zone. To comply with the, the per-house increased costs are estimated to be $1, and $ 9 for Climate Zone, $1,1 and $1,11 for Climate Zone 3, and $1, and $1,7 for Climate Zone for the electric/gas and heat pump houses, respectively. STATEWIDE ELECTRICITY AND ELECTRIC DEMAND SAVINGS Figure 9 presents the annual and cumulative statewide electricity savings from code-compliant new single-family housing in Texas for years through 9. Figure 1 presents the summer and winter electric demand reductions and the corresponding electric demand savings. The annual statewide electricity savings in 9 are estimated to be $11 million, and the total cumulative electricity savings over the period from to 9 are estimated to be $77 million. Although expected MWh savings in 9 (1,31,3 MWh) are higher than MWh savings (1,,7 MWh), a decrease of dollar savings in 9 is expected because of lower electricity rates in 9: from $.13/kWh to $.1/kWh. The electric demand reductions in 9 are estimated to be 9 MW for the summer and 7 MW for the winter periods. The corresponding electric demand savings from the reduced peak demands (i.e., avoided construction cost of a peaking plant) are estimated to be $1,7 million from to 9. Figure 11 shows the annual increased costs and the statewide electricity savings by the year the house was constructed. The annual statewide increased costs are estimated to range between $ million and $113 million. For the houses built between and, the cumulative electricity savings alone exceed the initial increased construction costs. If both electricity and electric demand savings are considered, the expected savings will be much higher. Figure 1 shows the cumulative statewide increased costs with the cumulative statewide electricity and demand savings from code-compliant, single-family residences built between and 9. The cumulative statewide costs over the eight year period from to 9 are estimated to be $7 million Proceedings of the Eleventh International Conference Enhanced Building Operations, New York City, October 1-, 11

9 ESL-IC Table. Per-House Increased Construction Costs Climate Zone Components 1 Ceiling Insulation R-7 R-3 R-3 $.9 $.11, $ 9 $ R.S. Means and 7 Window U/SHGC 1.11/.71./..7/. $ 1. $ 1. 7 $ 371 $ 7 Malhotra et al. ; Kim et al. 1 1 Wall Insulation R-1 R-11 R-13 $ - $ - 1,77 $ - $ - - Slab Insulation NR NR NR $ - $ - $ - $ - - AC SEER $ - $ - - $ - $ 3 1% of AC Cost (R.S. Means 7) Gas DHW EF...9 $ - $ - - $ - $ 17 ACEEE Guide (Amann et al. 7) Electric DHW EF...9 $ - $ - - $ - $ 7 ACEEE Guide (Amann et al. 7) Climate Zone 3 Components 1 $ $ 1, $ $ 9 Ceiling Insulation R-7 R-3 R-3 $.9 $.11, $ 1 $ 7 R.S. Means and 7 Window U/SHGC.7/../../. $ 1. $ $ $ 373 Malhotra et al. ; Kim et al. 1 1 Wall Insulation R-1 R-11 R-13 $ - $ - 1,1 $ - $ - - Slab Insulation NR NR NR $ - $ $ - $ - - AC SEER $ - $ - - $ - $ 3 1% of AC Cost (R.S. Means 7) Gas DHW EF...9 $ - $ - - $ - $ 17 ACEEE Guide (Amann et al. 7) Electric DHW EF...9 $ - $ - - $ - $ 7 ACEEE Guide (Amann et al. 7) Climate Zone Components 1 Total (b) All Electric House Total 1 (b) All Electric House Total 1 Total 1 $ 77 $ 1,11 $ 77 $ 1,1 Ceiling Insulation R-7 R-3 R-3 $.7 $.19, $ $ 1 R.S. Means and 7 Window U/SHGC.7/..37/NR./NR $ 1. $ $ $ Malhotra et al. ; Kim et al. 1 1 Wall Insulation R-1 R-11 R-1/3 c.i. $ - $ - 1,1 $ - $ - - Slab Insulation R-, ft R-, ft R-1, ft $ - $ $ - $ BCAP report (Paquette et al. 1) AC SEER $ - $ - - $ - $ 3 1% of AC Cost (R.S. Means 7) Gas DHW EF...9 $ - $ - - $ - $ 17 ACEEE Guide (Amann et al. 7) Electric DHW EF...9 $ - $ - - $ - $ 7 ACEEE Guide (Amann et al. 7) Total (b) All Electric House Total Increased Costs Per Unit Increased Costs Per Unit Increased Costs Per Unit Sq. Ft /Linear Ft Sq. Ft /Linear Ft Sq. Ft /Linear Ft Total Increased Costs Total Increased Costs Total Increased Costs $ 1,1 $ 1,7 $ 1,1 $ 1, References References References Electricity Savings (Million $) $1, $1, $ $ $ Cum. Elec. Savings Annual Elec. Savings $ $ Cum. Elec. Savings - - $1 $ $97 $17 $3 $1 $1 $77 Annual Elec. Savings - - $1 $3 $9 $7 $19 $1 $1 $11 Figure 9. Annual and Cumulative Statewide Electricity Savings from the Code Adoption for New Single- Family Residences in Texas: -9 9 Proceedings of the Eleventh International Conference Enhanced Building Operations, New York City, October 1-, 11

10 ESL-IC Annual Electric Demand Reductions (MW/year) 1, Cum.Demand Savings Sum demand reduction Win demand reduction Cum.Demand Savings - - $111 $3 $37 $ $717 $3 $99 $1,7 Sum demand reduction Win demand reduction $1, $1, $ $ $ $ $- Electric Demand Savings (Million $) Figure 1. Annual Statewide Electric Demand Reductions and Electric Demand Savings from the Code Adoption for New Single-Family Residences in Texas: -9 Million $/year $ $1 $1 $ $ Savings in 9 Savings in Savings in 7 Savings in Savings in Savings in Savings in 3 Savings in Cost (±1%) $ Built in Built in 1 Built in Built in 3 Built in Built in Built in Built in 7 Built in Built in 9 Million $/year Figure 11. Annual Increased Costs and Statewide Electricity Savings by Construction Year of Houses $, $1, $1, $1, $1, $1, $ $ $ $ $ Capacity Savings Built in 9 Built in Built in 7 Built in Built in Built in Built in 3 Built in -9 Cost for New SF Residences in Texas Built between Year Figure 1. Cumulative Increased Costs, Statewide Electricity and Electric Demand Savings Associated with the Code Adoption for Single-Family Residences in Texas: -9 while the cumulative electricity and demand savings are $1,3 million: $77 million from electricity savings and $1,7 million from demand savings. SUMMARY Statewide electricity savings and peak electric demand reductions achieved from the International Energy Conservation Code () adoption for single-family residences in Texas and the corresponding increase in construction costs over the eight-year period from through 9 are presented in this report. In the first part of the analysis, the impact of different versions of (1 and ) on energy savings and 1 Proceedings of the Eleventh International Conference Enhanced Building Operations, New York City, October 1-, 11

11 ESL-IC peak demand reductions were calculated at the individual building level using the ESL s IC3 simulation tool based on the DOE-.1e program for three counties in Texas. To calculate the electricity cost savings at the statewide level, the annual MWh savings from codecompliant new single-family housing in Texas for years through 9 which were reported in the Laboratory s Annual Reports to the TCEQ, were tabulated and multiplied by the annual average prices of Texas residential electricity published by the U.S. DOE EIA. To compute the statewide annual electric demand reductions, the peak demand reductions per house calculated in the building-level analysis were multiplied by the number of new single-family houses built in each climate zone of each year, and aggregated to annual totals with an annual degradation factor of %. To compute the avoided construction cost of a peaking plant (i.e., electric capacity savings), the calculated statewide electric demand savings in MW were multiplied by the average capital cost of a natural gas combined-cycle power plant, $1,1 per kw, with a 1% reserve margin. As a result, the annual statewide electricity savings in 9 are estimated to be $11 million, and the statewide electric demand reductions in 9 are estimated to be 9 MW for the summer and 7 MW for the winter periods. Finally, the cumulative statewide electricity and electric capacity savings from the electric demand savings over the eight year period from to 9 are estimated to be $1,3 million ($77 million from electricity savings and $1,7 million from capacity savings), which exceeds the increased construction costs estimated to be $7 million. ACKNOWLEDGEMENT Funding for this study was provided by the Texas State Legislature through the Texas Emissions Reduction Program (TERP). REFERENCES Amann, J.T., A. Wilson, and K. Ackerly. 7. Consumer Guide to Home Energy Savings: 9 th Edition. Washington, D.C.: American Council for an Energy-Efficient economy. Atmos Energy. 1a. Atmos Energy Tariffs for Mid- Tex: September 1 Mid-Tex GCR Rates. Dallas, TX: Atmos Energy. Retrieved September 3, 1, from st=mtx&pass=1 Atmos Energy. 1b. Atmos Energy Tariffs for West Texas: September 1 Texas (West) GCA Rates. Dallas, TX: Atmos Energy. Retrieved September 3, 1, from st=tx&pass=1 ASHRAE ANSI/ASHRAE Standard (RA ) - A Method of Determining Air Change Rates in Detached Dwellings. Atlanta, GA: American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc. ASHRAE. 1. ANSI/ASHRAE Standard -1 Ventilation for Acceptable Indoor Air Quality. Atlanta, GA: American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc. ASHRAE. 3. ASHRAE Handbook - HVAC Applications. Atlanta, GA: American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc. CPS Energy. 1. Fuel and Regulatory Charges. San Antonio, TX: CPS Energy. Retrieved November 9, 1, from ayments/fuel_and_regulatory_charges/index.as p Faruqui, A., R. Hledik, S. Newell, and H. Pfeifenberger. 7. The Power of Percent. The Electricity Journal. ():-77. Haberl, J., C. Culp, B. Yazdani, T. Fitzpatrick, and D. Turner.. Texas s Senate Bill Legislation for Reducing Pollution in Non-attainment and Affected Areas. Annual Report to the Texas Natural Resource Conservation Commission. ESL-TR-/7-1. College Station, TX: Energy Systems Laboratory, Texas A&M University System. Haberl, J., C. Culp, B. Yazdani, T. Fitzpatrick, J. Bryant, and D. Turner. 3. Energy Efficiency/Renewable Energy Impact in the Texas Emissions Reduction Plan (TERP), Volume II Technical Report. Annual Report to the Texas Commission on Environmental Quality, September to August 3. ESL- TR-3/1-. College Station, TX: Energy Systems Laboratory, Texas A&M University System. Haberl, J., C. Culp, B. Yazdani, D. Gilman, T. Fitzpatrick, S. Muns, M. Verdict, M. Ahmed, B. Liu, J.C. Baltazar-Cervantes, J. Bryant, L. Degelman, and D. Turner.. Energy Efficiency/Renewable Energy Impact in the Texas Emissions Reduction Plan (TERP), Volume II Technical Report. Annual Report to the Texas Commission on Environmental Quality, September 3 to August. Report ESL-TR-/1-. College Station, TX: Energy Systems Laboratory, Texas A&M University System. 11 Proceedings of the Eleventh International Conference Enhanced Building Operations, New York City, October 1-, 11

12 ESL-IC Haberl, J., C. Culp, B. Yazdani, D. Gilman, T. Fitzpatrick, S. Muns, M. Verdict, M. Ahmed, B. Liu, J.C. Baltazar-Cervantes, J. Bryant, L. Degelman, and D. Turner.. Energy Efficiency/Renewable Energy Impact in the Texas Emissions Reduction Plan (TERP), Volume II Technical Report. Annual Report to the Texas Commission on Environmental Quality, September to December. ESL-TR---. College Station, TX: Energy Systems Laboratory, Texas A&M University System. Haberl, J., C. Culp, B. Yazdani, D. Gilman, T. Fitzpatrick, S. Muns, M. Verdict, M. Ahmed, Z. Liu, J.C. Baltazar-Cervantes, J. Mukhopadhyay, L. Degelman, and D. Turner. 7. Energy Efficiency/Renewable Energy Impact in the Texas Emissions Reduction Plan (TERP), Volume II Technical Report. Annual Report to the Texas Commission on Environmental Quality, January to June 7. ESL-TR College Station, TX: Energy Systems Laboratory, Texas A&M University System. Haberl, J., C. Culp, B. Yazdani, D. Gilman, T. Fitzpatrick, S. Muns, Z. Liu, J.C. Baltazar- Cervantes, J. Mukhopadhyay, L. Degelman, and D. Claridge.. Energy Efficiency/Renewable Energy Impact in the Texas Emissions Reduction Plan (TERP), Volume II Technical Report. Annual Report to the Texas Commission on Environmental Quality, January 7 December 7. ESL-TR--1-. College Station, TX: Energy Systems Laboratory, Texas A&M University System. Haberl, J., C. Culp, B. Yazdani, D. Gilman, S. Muns, Z. Liu, J.C. Baltazar-Cervantes, J. Mukhopadhyay, L. Degelman, and D. Claridge. 9. Energy Efficiency/Renewable Energy Impact in the Texas Emissions Reduction Plan (TERP), Volume II Technical Report. Annual Report to the Texas Commission on Environmental Quality, January December. ESL-TR College Station, TX: Energy Systems Laboratory, Texas A&M University System. Haberl, J., C. Culp, B. Yazdani, C. Lewis, Z. Liu, J.C. Baltazar-Cervantes, J. Mukhopadhyay, D. Gilman, L. Degelman, K. McKelvey, and D. Claridge. 1. Energy Efficiency/Renewable Energy Impact in the Texas Emissions Reduction Plan (TERP), Volume II Technical Report. Annual Report to the Texas Commission on Environmental Quality, January 9 December 9. ESL-TR College Station, TX: Energy Systems Laboratory, Texas A&M University System. ICC International Energy Conservation Code. Falls Church, VA: International Code Council, Inc. ICC Supplement to the International Energy Conservation Code. Falls Church, VA: International Code Council, Inc. ICC.. International Energy Conservation Code. Falls Church, VA: International Code Council, Inc. ICC International Energy Conservation Code. Falls Church, VA: International Code Council, Inc. Kaplan, S.. Power Plants: Characteristics and Costs. CRS Report for Congress. RL37. Washington, DC: Congressional Research Service. Kats, G.H. et al Energy Efficiency as a Commodity. ACEEE Summer Study on Energy Efficiency in Buildings. Kim, H., Z. Liu, J.C. Baltazar, J. Haberl, C. Culp, B. Yazdani, and C. Montgomery. 1. Recommendations for 9 1% Above Code Energy Efficiency Measures for Residential Buildings. ESL-TR College Station, TX: Energy Systems Laboratory, Texas A&M University System. LBL DOE- BDL Summary Version.1E. LBL Report No Berkley, CA: Lawrence Berkeley Laboratory. Malhotra, M., J. Mukhopadhyay, Z. Liu, J. Haberl, C. Culp, B. Yazdani, and C. Montgomery.. Recommendations for 1% Above-Code Energy Efficiency Measures for Residential Buildings. ESL-TR College Station, TX: Energy Systems Laboratory, Texas A&M University System. NAECA.. National Appliance Energy Conservation Act. NAHB.. Builders Practices Report NAHB. 1. Builders Practices Report. NAHB.. Builders Practices Report 1. NAHB. 3. Builders Practices Report. NAHB.. Builders Practices Report 3. NAHB.. Builders Practices Report. 1 Proceedings of the Eleventh International Conference Enhanced Building Operations, New York City, October 1-, 11

13 ESL-IC NAHB. 9. Builders Practices Report. NAHB. 1. Builders Practices Report 9. NREL. 1. Building America House Performance Analysis Procedures. (NREL/TP--77) Golden, CO: National Renewable Energy Laboratory. p.3 Paquette, Z., J. Miller, and M. DeWein. 1. Incremental Construction Cost Analysis for New Homes: Building to the 9. Washington, D.C.: Building Codes Assistance Project. PUCT. 1. Average Annual Rate Comparison for Residential Electric Service: July 1. Austin, TX: Public Utility Commission of Texas. Retrieved September 3, 1, from cfm RECenter. 11. Building Permits Texas, Real Estate Center, Texas A&M University, College Station, Texas. Retrieved January, 11, from R.S. Means.. Residential Cost Data: 1 st Annual Edition. Kingstone, MA: R.S. Means Company, Inc. R.S. Means. 7. Residential Cost Data: th Annual Edition. Kingstone, MA: R.S. Means Company, Inc. US DOE EIA. 11. State Data for Prices: Current and Historical Monthly Retail Sales, Revenues, and Average Retail Price by Sector. Energy Information Administration, U.S. Department of Energy. Retrieved February 1, 11, from m 13 Proceedings of the Eleventh International Conference Enhanced Building Operations, New York City, October 1-, 11