benchmarking/performance measuring

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

ASHRAE Region VI CRC

Paul A. Torcellini, Ph.D., PE

May 8, 2009

www.highperformancebuildings.gov

Tech Session 4: Benchmarking/ Performance Measuring

National Renewable Energy Laboratory Innovation for Our Energy Future

Case Study Buildings– Oberlin College Lewis Center

• Oberlin, Ohio • goal: zero net site energy use (79%)

– Zion Visitor Center• Springdale, UT • goal: 70% energy cost savings (65%)

– Cambria Office Building• Ebensburg, PA • goal: 66% energy cost savings (43%)

– Chesapeake Bay Foundation (CBF)• Annapolis, MD • goal: LEED 1.0 Platinum Rating (25%)

– Thermal Test Facility (TTF)• Golden, CO • goal: 70% energy savings (51%)

– BigHorn Home Improvement• Silverthorne, CO • goal: 60% energy cost savings (53%)

– Science House, Science Museum of Minnesota• St. Paul, Minnesota• goal: zero net site energy use (139%)

Different Metrics-Different Results

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Oberlin BigHorn TTF Cambria Zion CBF

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Percent Net Source Energy Savings

Percent Net Site Energy Savings

Percent Site Energy Savings

Percent Energy Cost Savings

measured data vs. simulated basecasesimulated as-built vs. simulated basecase

BigHorn Home Improvement Center

18,400 sqft retail store and 24,000 sqftwarehouse

DaylightingNatural ventilation (no mechanical cooling)Radiant floorsTranspired solar collectorPV

Ventilation PreheatVentilation PreheatOver 70% efficientOver 70% efficientActs as a building skinActs as a building skin11¢¢/kWh heat production/kWh heat production

Transpired Solar CollectorTranspired Solar Collector

Electric Lighting and DaylightingElectric Lighting and Daylighting

Daylighting System PerformanceDaylighting System Performancesavings: daylighting = 65%; overall = 79%

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Zion Visitor Center

7.2 kW PV system (UPS)7.2 kW PV system (UPS)Passive evaporative coolingPassive evaporative coolingExcellent thermal envelopeExcellent thermal envelopeTrombeTrombe wallswallsOverhangsOverhangsDaylightingDaylighting

Zion Visitor Center

Daylighting

Operable Windows

Overhangs

Downdraft Evaporative Cooltower

Cool Air

Hot Air

Trombe Wall

Heating

Radiant Ceiling Panels

Cooltowers

HVAC System

Envelope is integral to the heating and cooling system– Cooltowers and Trombe wall– Natural ventilation

Ceiling fansBathroom/office exhaust fansNo ductworkElectric radiant heat (propane expensive)Demand responsive EMSNo fuel storage or mechanical rooms

PV System

7.2 kW (24 300-W modules)2 single phase

inverters (one with UPS)

PV can meet loads of phone, security, POS, and cooltowers (UPS battery backup)

Grid power out 40 times during monitoring year.

PV provides about 8% of annual total.

Other Features

Extensive daylightingGood thermal envelopeTrombe wall heatingOverhangsPV can meet loads of

phone, security, POS, and cooltowers (UPS battery backup)

Grid power out 40 times during monitoring year.PV provides about 8% of annual total.70% energy savings (measured)

Peak Demand

Plot of 15-minute data showing demand responsive controls

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Measured Energy Performance$0.43/year to operate (including plug loads)27.0 kBtu/ft2/year (including plug loads, but no PV) 7,860 kWh produced by PV or 8% of total (24.7 kBtu/

ft2/year net)

Visitor Center Heating

Fee Station

Ceiling and Exhaust Fans

Comfort Station Cooling

Comfort Station Plug Loads

Visitor Center Domestic Hot Water Comfort Station Domestic

Hot Water

Visitor Center Plug Loads

Outdoor

Comfort Station Visitor Center Switch Controlled

Visitor Center Computer Controlled

Visitor Center Cooling

Comfort Station Heating

Equipment/Other33%

HVAC36%

Lighting31%

Lewis Center for Environmental Studies

13,600 sqft classroom and offices60 kW PV system on roofDaylightingGround-source Heat PumpsWater TreatmentNatural Ventilation


Oberlin Lewis Center Monthly Energy Performance January 2000 - December 2002

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Utility BillsEquipmentTotal LightsTotal CoolingTotal HeatingPV Production

The Value of Monitoring

Receptacles

Emergency receptacles

PV system consumption

DHW

Auditorium lights

Indoor room lights

Hydronic circulation pumps 3-6

VSD Hydronic circulation pumps 1-2

Room Heat Pumps

Classroom energy recovery unit

Auditorium energy recovery unit

Emergency lights

Sidewalk lights

Parking lot lights

Classroom ventilation heat pump

Auditorium heat pump

Hydronic system electric boiler

Wastewater treatment

Elevator

Total Equipment

28%

Total Lights13%

Total HVAC59%

End Loads


NREL Thermal Test Facility (TTF)

10,000 sqft Laboratory and OfficeTypical steel frame buildingGood insulation packageSimple daylighting design


Plug Loads22.0%

Exterior Lights4.2%

Hot Water1.1%

Heating4.0%

Cooling1.6%

Fans/Pumps1.8%

Lighting12.1%

Savings52.9%

Plug Loads22.0%

Exterior Lights4.2%

Hot Water1.1%

Heating2.7%

Cooling8.3%

Fans/Pumps4.6%

Lighting57.0%

Loads Example

Code Building

Final Design

72% savings excluding plug loads and exterior lights

Available Roof Layouts

More Daylighting…

Education and Marketing

Image…

High Performance Building’s Database

• Shared, on-line repository of in-depth descriptions and data on high-performance and green buildings

• Commercial, residential, campus• Single database, multiple portals• Examples of low-energy buildings to motivate

industry• Mechanism for others to report on building

performance and lessons learned

http://www.eere.energy.gov/buildings/database/

Case Study Database Objectives

• Lack of comprehensive energy-based case studies

• Provides feedback to both DOE and industry– Industry needs proof that low-energy is possible– DOE needs feedback to understand successes and failures

in real world examples

• Create a standardized reporting format for building energy performance

Pages for – Overview, Process, Finance, Land Use,

Site/Water, Energy, Materials, Indoor Environment, Images, Ratings, Lessons Learned, and Learn More

Features

Pages for – Overview, Process, Finance, Land Use,

Site/Water, Energy, Materials, Indoor Environment, Images, Ratings, Lessons Learned, and Learn More

Energy Table Page

• Multiple energy tables– Allows for comparisons/tracking

with time• Basecase, simulated, utility data

(by year)

• Longer term reporting• Narratives• Data Sources and Reliability

Portals– DOE High-Performance Buildings Database (101 projects)– BuildingGreen, Inc. (230 projects)– American Institute of Architects (92 projects)

• Top Ten Winners– U.S. Green Building Council (108 projects)

• LEED Case Studies– Federal Energy Management Program (44 projects)

• New Federal buildings must be entered by EPACT2005– Efficiency Vermont (4 projects)– Cascadia Chapter USGBC (35 projects)– DOE Net Zero Energy Buildings (4 projects)

• Buildings that have measured performance of ZERO– ASHRAE (5 projects)

• AEDG Case Studies– DASH (New project)

• Focus on financial/real estate/productivity metrics– International Energy Agency – Solar Heating and Cooling Programme Task 40

• International case studies for Zero and near Zero Commercial and Residential Project (new as of 11/15/08)

– Massachusetts Technology Collaborative (20 projects)– There are others…

Distribution of Projects

DASH


High-Performance Buildings Database

Share successes and lessons learned about projects

Public databaseActual Energy InformationFEMP, USGBC, AIA, DOE all have “front

ends”A special section for ZEB’s.www.highperformancebuildings.gov

You can enter projects…

• Go to www.highperformancebuildings.gov– enter the database– Create a login and submit a project

Lessons Learned from the HPBd

• Getting energy data is hard– Even utility bills– This is the part that viewers want to see the most– This is one of the few real measures of success – it can be

measured and quantified

• The risk of sharing lessons learned– Need to be willing to share mistakes– Needed to advance the industry—or we will never get there.

• Transparency is key.


What are [Net] Zero Energy Buildings?

Conceptually, a building that has no adverse energy [or environmental] impact [because of its operation]

ZERO is not easy to define!– Disconnect all utility interfaces?– Net energy transfer across boundary?– Where is the boundary?


Definitions of NZEB’s

Net Zero Site EnergyNet Zero Source EnergyNet Zero Emissions Net Zero Energy Cost

Boundaries and metrics


Net Zero Site Energy

Measured at the interface of the building to the utility (point of sale)

Easy to measure/verify (vested interest in having the right number)

Can favor electricity over on-site combustionEncourages energy efficient designs at the

building levelWhat is the “site?” Building footprint or property


Net Zero Source Energy

With current information, really just site with multipliers for different fuels

Has a grid (more global) impactDepends on dispatch of power

generation– Fuel source– Incremental dispatch

Daily and seasonal dependencies Regional (non climatic) dependenciesNot a strong focus on building efficiency


Net Zero Energy Cost

What the owner really sees(Also) based on site measurementsEasy to verifyDemand componentHigh regional variationsHighly dependent on rate structures

(demand and fixed charges cannot be negated)

Cost volatility Market driven comparisonsCannot do this on a large scale (Who would pay

the utility?)


Net Zero EmissionsAlso based on site numbers, typically with

national or regional multipliers based on generation location

Same issues as source

If a building has zero source energy and therefore zero emissions, is it really a zero emissions building?


Renewable Hierarchy

• Energy efficiency• Renewable in/on building• Renewable in/on property• Import renewables

(wood chip, other biofuels)• Purchase renewable credits


Ending Thoughts…

Zero takes a coordinated effort with the architect and the engineering

The little things make the difference in getting to zero (as you get to zero, little is significant)

The owner needs to set measurable goals and communicate these goals to the design team

The solution is not bigger supplies


Questions?

www.highperformancebuildings.gov

benchmarking/performance measuring

Design

sustainable energy

minnesota goal

md goal

ohio goal

ut goal

pa goal

pv system ups7

cooling system cooltowers