1 Mission Valley Power Energy Efficient Home Program and GSHP Deemed Savings Analysis September 30, 2008

2 Background Mission Valley Power (MVP) requested that the RTF review its specifications for a new residential construction program to establish a deemed savings value and cost- effectiveness MVP also provided an analysis of the potential savings from requiring R-10 full under slab insulation with an R-5 slab edge thermal break for RTF review and potential adoption as a deemed measure Lincoln Electric also requested that the RTF review the cost-effectiveness of Geothermal Heat Pumps installed in MVP or Energy Star homes

3 MVP Deemed Savings Analysis – R-10 Full Slab w/R-5 Thermal Break Used WattSUN Assumed MT Code as baseline, then modeled full slab insulation w/ thermal break (UA 549) vs UA 518) –Wall (Above Grade) = R-19 –Wall (Below Grade) = R-11 (0.054 base/0.056 w/full slab) –Attic = R-38 –Glazing = U –Door = U-0.19 –On grade slab – R-0 (F-0.73) & R-10 w/R-5 TB (F-0.36) –Below grade slab = R-0 (F-0.56) & R-10 w/R-5 TB (F-0.42) MVP Supplied Cost Data - $0.85 sq.ft.

4 Results of Review – R10 Full Slab WattSun Savings = 1.5 kWh/sq.ft. slab –WattSUN savings are based on (TMY2) –Used Kalispell weather –Zonal electric heating assumed SEEM Savings –Based on TMY 3 –Used Missoula weather (Zone 3 Reference site) –Analyzed 5 heating system types

Results of Review – R10 Full Slab Savings (2) Heating System TypeSavings (kWh/sq.ft.) FAF w/CAC1.2 FAF1.2 Zonal1.1 HP - Fed Std HSPF HP - Estar HSPF

Results of Review – R10 Full Slab Cost- Effectiveness (3) Heating System TypeTRC Benefit/Cost Ratio FAF w/CAC1.5 FAF1.5 Zonal1.4 HP - Fed Std HSPF HP - Estar HSPF

7 MVP Deemed Savings Analysis – Energy Efficient Home Used WattSUN model w/Kalispell Weather Assumed MT Code as baseline, compared to –EStar Home BOP 2 –MVP Home specifications WattSUN Results –EStar Home BOP 2 = 32% savings –MVP Home = 36% savings

Savings Review Input Assumptions – Crawlspace Home * Assumed value for unconditioned crawl space. Construction not allowed under EStar BOP2. Component MT Code VentedMVP Vented MT Code SealedMVP Sealed FloorR-21R-38None Crawl PerimeterN/A R-19R-21 GlazingU-0.35U-0.32U-0.35U-0.32 DoorsU-0.19U-0.16U-0.19U-0.16 Wall (Above Grade)R-21 StdR-26 AdvR-21 StdR-26 Adv AtticR-38R-49 AdvR-38R-49 Adv Infiltration0.35 ach 0.30 w/o HRV0.35 ach 0.30 w/o HRV Overall UA

Savings Review Input Assumptions – Slab & Heated Basement * MT Code does not require below grade walls to be insulated until “finished.” EStar & MVP require R-21 insulation at time of construction. Component MT Code SlabMVP SlabBOP2 Slab MT Code Basement MVP Basement BOP2 Basement Slab on GradeR-13 per.R-10 fullR-10 per.N/A Slab below GradeN/A NoneR-10 FullR-10 per. GlazingU-0.35U-0.32U-0.30U-0.35U-0.32U-0.30 DoorsU-0.19U-0.16U-0.19 U-0.16U-0.19 Wall (Above Grade)R-21 StdR-26 AdvR R-21 StdR-26 AdvR Wall (Below Grade)N/A R-11R-21 AdvR-19 AtticR-38R-49 AdvR-38 R-49 AdvR-38 Infiltration0.35 ach 0.30 w/o HRV0.20 ach0.35 ach 0.30 w/o HRV0.20 ach Overall UA

Results of Review – MVP Home Zonal Electric Space Heating Savings Annual Use (kWh) Slab on Grade Vented Crawl Sealed Crawl* Heated Basement MT Code 19,35718,51420,68716,684 EStar BOP2 17,24315,08617,44212,105 MVP 15,04614,61017,84213,057 Savings Over MT Code (kWh/yr) EStar BOP2 2,1143,4293,2454,579 MVP 4,3103,9042,8453,627 Percent Savings Over MT Code Estar BOP2 11%19%16%27% MVP 22%21%14%22% 10 Not Equivalent To or Better Than EStar BOP2

Results of Review – MVP Home Forced Air Furnace w/o CAC Space Heating Savings Annual Use (kWh) Slab on Grade Vented Crawl Sealed Crawl Heated Basement MT Code 25,28326,12724,33717,644 EStar BOP2 17,24315,08617,44212,105 MVP 19,73121,03021,00213,824 Savings Over MT Code (kWh/yr) EStar BOP2 8,04011,0416,8945,539 MVP 5,5525,0973,3353,820 Percent Savings Over MT Code Estar BOP2 32%42%28%31% MVP 22%20%14%22% 11 Not Equivalent To or Better Than EStar BOP2

Results of Review – MVP Home Air Source Heat Pump Space Heating Savings Annual Use (kWh) Slab on Grade Vented CrawlSealed Crawl Heated Basement MT Code 14,79515,95914,51710,066 EStar BOP1 11,98411,08810,9947,666 MVP 11,67912,99012,5308,039 MVP+9,95711,31310,6426,471 Savings Over MT Code (kWh/yr) EStar BOP1 2,8104,8713,5232,400 MVP 3,1162,9701,9862,027 MVP+ 4,8384,6463,8753,595 Percent Savings Over MT Code EStar BOP119%31%24% MVP 21%19%14%20% MVP+ 33%29%27%36% 12 MVP+ = Requires PTCS Controls (Outside Thermostat & No First Stage Resistance & ARI Staging

MVP Home Proposed Lighting Specifications Impact on Savings MVP Proposal – 25% of CFL EStar Requirement – 50% of CFL Crawl/SlabBasementCrawl/SlabBasement W/sfkWh/yr Gains Btuh MT Base MVP EStar

Results of Review – MVP Home Zonal Electric Space Heating + Lighting Savings Annual Use (kWh) Slab on Grade Vented Crawl Sealed Crawl Heated Basement MT Code 22,16721,32523,49820,118 EStar BOP2 19,00916,85219,20914,264 MVP 17,34316,90720,13915,863 Savings Over MT Code (kWh/yr) EStar BOP2 3,1584,4734,2895,854 MVP 4,8244,4183,3594,255 Percent Savings Over MT Code Estar BOP2 14%21%18%29% MVP 22%21%14%21% 14 Not Equivalent To or Better Than EStar BOP2

Results of Review – MVP Home Forced Air Furnace w/o CAC Space Heating Savings Annual Use (kWh) Slab on Grade Vented Crawl Sealed Crawl Heated Basement MT Code 28,09428,93827,14721,078 EStar BOP2 19,00916,85219,20914,264 MVP 22,02823,32723,29916,630 Savings Over MT Code (kWh/yr) EStar BOP2 9,08412,0857,9386,814 MVP 6,0665,6113,8484,448 Percent Savings Over MT Code Estar BOP2 36%46%33%39% MVP 24%21%16%25% 15 Not Equivalent To or Better Than EStar BOP2

Results of Review – MVP Home Air Source Heat Pump Space Heating + Lighting Savings Annual Use (kWh) Slab on Grade Vented CrawlSealed Crawl Heated Basement MT Code 17,60518,77017,32713,500 EStar BOP1 13,75112,85512,7619,824 MVP 13,97515,28614,82710,845 MVP+12,25313,60912,9398,630 Savings Over MT Code (kWh/yr) EStar BOP1 3,8545,9154,5673,676 MVP 3,6303,4832,5002,655 MVP+ 5,3525,1604,3894,870 Percent Savings Over MT Code EStar BOP122%32%26%27% MVP 21%19%14%20% MVP+ 30%27%25%36% 16 MVP+ = Requires PTCS Controls (Outside Thermostat & No First Stage Resistance & ARI Staging

17 Summary of MVP Home Findings MVP Home Equivalency with Energy Star BOPs Foundation/SystemZonal Electric Electric FAFAir Source HP* Slab-on-Grade Vented Crawlspace Sealed Crawlspace Heated Basement *Requires PTCS Controls (Outside Thermostat & No First Stage Resistance Heating & ARI Staging of Backup

Recommendations Establish deemed savings for R10 full slab insulation Establish New Technical Compliance Option (TCO) for MVP Homes that produce savings equivalent to existing Energy Star Builder Option Packages (BOPs) Establish deemed savings for MVP Homes that are not equivalent to Energy Star Establish deemed savings for GSHP conversions and upgrades installed MVP Homes

Geothermal Heat Pump Cost- Effectiveness Existing GSHP Cost Data from Oregon Trail Coop, supplemented by Ravalli, Flathead and Lincoln Electric –OTEC Average Installed Cost/Ton = $3,363 –MT Coop Average Installed Cost/Ton = $3,327 All GSHP Installations assumed to install de-superheater ($1150) which saves additional 1200 kWh/yr (33% of DHW use) SEEM FAF Use adjusted for GSHP COP and SEER –COP = 3.3 –SEER = 16 No PTCS Duct Sealing or Commissioning Assumed All cost adjusted to 2006$

Cost-Effectiveness Input Assumptions – Space Heating Use

Cost-Effectiveness Input Assumptions - Costs System TypeFirst Cost Annual O&M Periodic Replacement Convert Electric FAF to GSHP $10,090$25$350 Upgrade Air Source HP to GSHP $6,790 $-

Cost-Effectiveness Results – Total Resource Benefit/Cost Ratio MeasureTRC B/C Ratio Existing Crawlspace Convert Electric FAF to GSHP1.6 Existing Basement Convert Electric FAF to GSHP1.3 MVP/EStar Crawlspace Convert Electric FAF to GSHP1.1 MVP/EStar Basement Convert Electric FAF to GSHP0.9 MVP/EStar Crawlspace Upgrade Air Source HP to GSHP0.7 MVP/EStar Basement Upgrade Air Source HP to GSHP0.6