The Opportunity for Gas-Fired Heat Pump Water Heaters

Transcription

1 The Opportunity for Gas-Fired Heat Pump Water Heaters ACEEE Hot Water Forum November 4 th 5 th, 2013 Paul Glanville, PE Gas Technology Institute

2 Thousands of Units What does the U.S. Market Look Like? 12,000 10,000 8,000 6,000 4,000 2,000 0 VOLUME SALES OF WATER HEATERS Projected Heat Pump Water Heaters Solar Thermal Storage tanks Oil Hybrid Water Heater Gas Storage Non-Condensing Residential Gas Storage Non-Condensing Commercial Gas Storage Condensing Residential Gas Storage Condensing Commercial Gas Instantaneous Non-Condensing Gas Instantaneous Condensing Electric Storage Residential Electric Storage Commercial Electric Instantaneous Indirect Cylinders Combi Boilers > Lion s share of products sold are still low efficiency gas and electric storage residential water heaters > Growth in gas condensing tankless water heaters > Electric heat pump water heaters growing as well, however 2012 shipments were on the order of 50,000/yr. Data Source: Parker, M. American Water Heating Dynamics: Present and Future, ACEEE HWF (2011 ). 2

3 What does the U.S. Market Look Like? Value of 2010 Shipments - $3.1 Billion Gas Storage Non-Condensing Residential Electric Storage Residential Gas Instantaneous Non-Condensing Gas Storage Non-Condensing Commercial Gas Storage Condensing Commercial Gas Instantaneous Condensing 1, Electric Storage Commercial Indirect Cylinders Electric Instantaneous Solar Thermal Storage tanks Gas Storage Condensing Residential > Similar story to units shipped, low- efficiency residential storage products (gas and electric) comprise over 2/3 the value of 2010 shipments. > Tankless water heaters (gas condensing/noncondensing and electric) are high value products relative to shipment numbers Heat Pump Water Heaters Hybrid Water Heater Oil Combi Boilers > Higher efficiency translates to higher value, but challenge for higher volume. Data Source: Parker, M. American Water Heating Dynamics: Present and Future, ACEEE HWF (2011 ). 3

4 High-Efficiency Gas Options While market is predominantly EF residential Gas Storage Water Heaters (GSWH), options for a high-efficiency retrofit are: > Non-condensing EnergyStar water heater with EF, current models require electrical service. > Condensing GSWH/Hybrid, requiring venting upgrade and electrical service. Most currently rated with thermal efficiency (TE), recent study has found units with TE > 90% have EF of less than 0.80* > Convert to non-condensing or condensing Gas Tankless Water Heater (GTWH), with an EF typically, requiring venting upgrade, electrical service, and often larger gas piping. Delivered efficiency of TWHs is in dispute due to cyclic/startup losses not covered by EF, some groups de-rate the EF of TWHs by 9%** * Davis, R. Laboratory Testing of Advanced Storage Water Heaters, ACEEE HWF (2012). ** RESNET. Results of Electronic Ballot of RESNET Board of Directors on Adopting Proposed Standard Amendment on Adjusting Instantaneous Water Heater Efficiency (2012). 4

5 Gas-fired Heat Pump Water Heating Is there an opportunity for a gas-fired heat pump water heater with an EF > 1.0? Technical: Numerous heat pump cycles are technically feasible: > Engine-driven vapor compression > Direct-fired absorption cycle: NH 3 -H 2 O, Strong Salt-H 2 O common pairs > Solid sorption/adsorption: silica gel-h 2 O, zeolite-h 2 O > Stirling engine cycles & variants > Thermoacoustic cycles Limited commercially available options, primarily foreign suppliers, often not dedicated water heating device (e.g. absorption chiller). 5

6 Gas-fired Heat Pump Water Heating If technically feasible, is there a economic and/or energy saving opportunity? Comparative Analysis - Assembling laboratory test data with daily electricity & natural gas consumption: > CEC Residential Gas Water Heating Program, GTI & PG&E performing laboratory testing on residential gas tankless and gas storage water heaters respectively* > Laboratory Characterization of Electric HPWHs, GTI testing three of the major EHPWH products. Results for analysis are for EF of ** > Laboratory Testing of Prototype Gas-Fired Residential Absorption HPWH, GTI testing of prototype absorption GHPWH under standard and field conditions. Results for 1 st gen. prototype correspond to EF *** * Kosar, D. et al. Residential Water Heating Program - Facilitating the Market Transformation to Higher Efficiency Gas-Fired Water Heating - Final Project Report. CEC Contract CEC (2013) Link: ** Glanville, P. et al. Parametric Laboratory Evaluation of Residential Heat Pump Water Heaters, Trans. of ASHRAE v. 118 pt. 1, Chicago, IL. (2012). Link: *** Garrabrant, M. et al. Development and Validation of a Gas-Fired Residential Heat Pump Water Heater - Final Report. DOE Contract EE (2012). Link: 6

7 Comparative Analysis Using 24 Hour Laboratory Test Data from GTI & PG&E (Storage GSWH Only), quantify the operating cost and source energy savings opportunity for GHPWHs. > Electricity and gas consumption measured over 24 hour test with standard (US DOE) 64 gal/day hot water draw pattern 24 Hour energy consumption accounts for change in stored energy (Q DA in standard calcs) > Operating cost and source energy savings extrapolated to annual for CA & TN Resource Cost California Tennessee Note Electricity $/kwh Gas $/therm Site/Source Energy Factor California Tennessee Note 2012 State Average - EIA Electricity Western/Eastern grid respectively Gas EIA Cost Data: Electricity - ; Natural Gas - Site/Source Factors: 7

8 Annual Source Energy Consumption (MMBtus) Comparative Analysis: DOE Pattern Gas Storage WH Tankless WH Gas Heat Pump WH AOS Electric Heat Pump WH GE Electric Heat Pump WH TN Dark Shade; CA Light Shade 8

9 Annual Operating Cost Comparative Analysis: DOE Pattern $ $ $ Gas Storage WH Tankless WH Gas Heat Pump WH AOS Electric Heat Pump WH GE Electric Heat Pump WH $ $ $ $50.00 $0.00 TN Dark Shade; CA Light Shade 9

10 Concluding Thoughts > Significant reductions in source energy consumption and operating cost challenging for higher efficiency GSWHs vs. minimum efficiency products. Minimum efficiency GSWHs still represents majority of market > Tankless WH products have attractive energy/operating cost savings based upon standard draw pattern. Realized savings as installed may differ > EHPWHs offer attractive source energy savings relative to most GSWHs in regions with lower electricity site/source ratios (Pac. NW, West Coast). Operating cost savings may not be realized due in large part to low natural gas prices. > Good opportunity exists for Gas-Fired Heat Pump Water Heater with EF > 1.0, yielding source energy and operating cost savings vs. all other options. Greater source energy savings with solar-hybrid DHW systems possible. 10

11 Questions? Contact Information Gas Technology Institute Paul Glanville 11