MEASURING NZE HOME PERFORMANCE IN THE NORTHEAST

Transcription

1 MEASURING NZE HOME PERFORMANCE IN THE NORTHEAST Nick Collins, ERS Ryan Pollin, ERS Headquarters: 120 Water Street, Suite 350, North Andover, MA With offices in: CA, CT, ME, NY, OR, TX, VT

2 OUTLINE Project and Program Introduction NZE Basics M&V Methods Review of Example Homes Observations and Discussion This evaluation is still in progress, all data and observations are preliminary and have not been approved by the Organization 02/02/2017 2

3 PROJECT AND PROGRAM INTRODUCTION 02/02/2017 3

4 PROGRAM M&V BASICS Measurement & Verification 3 rd party revisits completed sites to reassess performance and savings Compare assumed energy performance with more defensible, measured values Identify what works and doesn t, feed lessons back to program 02/02/2017 4

5 THE SCOPE OF THE PROJECT Establish the actual energy use and performance of a population of net zero homes in the Northeast Examine the relationship between energy use and various independent variables Examine the relationship between energy use and occupant behavior 02/02/2017 5

6 THE STATUS OF THE PROJECT Recruited 19 homes for extensive metering Meters installed ~March 16 to Dec 16 Some preliminary site results Aggregate analysis in process 02/02/2017 6

7 PROGRAM INTRODUCTION A Northeast Low-Rise Residential New Construction program provides technical and financial support for the construction of net zero energy homes Participant homes are modeled in REM/Rate HERS Index under 10 qualifies as NZE NZE sub-program began /02/2017 7

8 PROGRAM POPULATION Program Years units, predominantly single-family NC Size range from 756 4,382 SF Tightness range from ACH 50 1 Contractor built 50%+ of program homes ~75% GSHP and 25% ASHP Std DHW, typically preheated Most lighting still CFL All homes generate with PV 02/02/2017 8

9 NET ZERO BASICS 02/02/2017 9

10 WHAT IS A ZERO ENERGY BUILDING? 2015 DOE Definitions Zero Energy Building Zero Energy Campus Zero Energy Portfolio Zero Energy Community Net Zero Energy Zero Net Energy Nearly Zero Blah Blah Blah 02/02/

11 ZEB / NZE DEFINITION Zero Energy Building An energy-efficient building where, on a source energy basis, the actual annual delivered energy is less than or equal to the on-site renewable exported energy. 02/02/

12 SITE VS SOURCE ENERGY Site Energy The amount of energy consumed onsite as measured by utility meters. Source Energy The total amount of energy needed to deliver the consumed energy, including: Primary fuels extraction, processing and transport Energy losses in thermal power plants T&D losses to site Electricity Factor: 3.1 (National) or 3.4 (Northeast) Natural Gas Factor: ~1 02/02/

13 M&V METHODS 02/02/

14 METHODS OVERVIEW Site Work Recruit all homes High-level energy inventory Equipment Plug loads Lighting technology Occupant Interview Deploy current transducers March-December /02/

15 METHODS OVERVIEW Data Analysis Meter energy consumption of subsystems Collect utility data to corroborate Establish gross and net energy use Identify correlations between independent variables and energy use Weather Normalization Occupancy Normalization as needed 02/02/

16 METHODS - SITE WORK MTCOOI: meter the crap out of it Whole Home Net Solar Production Heat Pumps Domestic Hot Water ERV Well Pump Electric Vehicles & other 02/02/

17 METHODS DATA ANALYSIS Regression analysis, corroborated using utility data Weather normalized 8760 analysis kbtu/s.f. as prime metric Consumption load profiles Generation load profiles Peak demand period analysis End-use breakdown 02/02/

18 METHODS DATA ANALYSIS Look for correlations between systems/behavior and energy use Small sample sizes, still informative GSHP vs. ASHP Occupied vs. Unoccupied energy use Impacted by temperature setbacks? Impacted by occupant use of plug loads? Energy use vs. Occupant density 02/02/

19 EXAMPLE HOMES AND PRELIMINARY PERFORMANCE 02/02/

20 EXTERIORS 02/02/

21 ENVELOPES Spray-Foam Roof Insulation Superior Wall Insulated Concrete Form (ICF) 02/02/

22 MECHANICALS Heat Pump Furnace Energy Recovery Ventilator Ground-Source Geothermal Well Pump Domestic Hot Water Preheat 02/02/

23 ELECTRICALS Main Electrical Panel PV Inverters PV Array 02/02/

24 EXAMPLE HOME A Built years of daily kwh consumption and production data 3,237 square feet ICF walls GSHP two vertical wells 7 kw Solar PV HERS Index 6 02/02/

25 EXAMPLE HOME A Historical Average daily kwh consumption vs. OAT 02/02/

26 EXAMPLE HOME A Historical Consumption over time 02/02/

27 EXAMPLE HOME Historical PV production over time 02/02/

28 EXAMPLE HOME A Is it a zero energy building? Year kbtu/s.f. - consumption Net Source energy (kbtu/yr) Notes (27,522) (24,516) (35,564) (17,459) (30,597) (2,688) Purchased electric vehicle RECS 2009 Average NE home kbtu/s.f. 02/02/

29 EXAMPLE HOME B 1800s Farmhouse, renovated months meter data 2,134 square feet Wood-frame walls, roll insulation GSHP 10.6 kw Solar PV HERS Index 7 02/02/

30 EXAMPLE HOME B Property Value Annual kwh Consumed 25,044 Annual kwh Produced (24,507) Annual kwh Exported (2,949) Annual kwh Net 537 Consumption EUI 36.9 Net EUI 0.8 kwh Consumed per Occupant 12,522 kwh Net per Occupant 268 Percent of Energy Offset by On-site Production 98% Achieving Net Zero? No 02/02/

31 EXAMPLE HOME B Is it a zero energy building? Year kbtu/s.f. - consumption Net Source energy (kbtu/yr) Notes N/A ,802 Typical weather year RECS 2009 Average NE home kbtu/s.f. 02/02/

32 NEXT STEPS Finish site analyses Aggregate analysis of performance metrics Ground-Source vs. Air-Source Construction Age Occupant Density Occupant behaviors and associated energy performance 02/02/

33 OBSERVATIONS AND DISCUSSION 02/02/

34 EARLY OBSERVATIONS Net zero neighborhoods provide a natural laboratory for examining occupant impact Numerous participants in one neighborhood, near identical construction methods and design Very different occupant characteristics and attitudes 02/02/

35 EARLY OBSERVATIONS 88% of metered homes report they do not set back thermostats or make an effort to turn off lights Paraphrasing: I already made my investment by buying a NZE home, why bother to set back the thermostat? Rebound effect? 02/02/

36 THOUGHTS FOR DISCUSSION What affect does the NZE label have on energy behaviors? What expectation can we have of NZE homes to achieve further savings? What is the role of super-efficient equipment and behavior change activities in a time of low-cost PV? 02/02/

37 THOUGHTS FOR DISCUSSION Performance is reliably achieved in normal looking and feeling homes Homes, at least those built by experienced NZE contractors, are cost competitive in the real estate market If we can build NZE homes and sell them at a competitive cost, then what is the next barrier to overcome? How can the now-niche NZE market scale? 02/02/

38 THANK YOU! Nick Collins Ryan Pollin 02/02/

39 FOR SALE AND SOLD COST Homes currently for sale or sold since ,000 s.f. 3,000 s.f acre lots Similar amenities Similar age 02/02/

40 FOR SALE AND SOLD COST $/s.f Net zero homes Traditional homes /02/