Pathway to Net-Zero Energy Commercial Buildings

Gregory B. Stark, P.E.National Renewable Energy

LaboratoryUNL Net-Zero Energy Workshop

Introduction• Why Net Zero is Important• Can We Get to Zero Energy?• Commercial Building Initiative

Why Net Zero is Important• Buildings are the Largest Energy Consumer in the U.S.– 40% of primary energy, 72% of electricity, 55% of natural gas

Commercial Sector Trends• Energy use increasing 1.6% per year – faster that energy efficiency improvements

51015202530

1985

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1995

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2005

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2025

Sector energy (quads)

0

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GDP (trillion $)

Delivered(site) energy

Total (source)energy

G rossDom esticProduct

Can We Get to Zero Energy?

Tremendous Potential in Buildings• First Database of Net-Zero Energy Buildings: zeb.buildinggreen.com

Building LocationFloor Area (ft2)

Annual Purchased Energy

(kBtu/ft2)

Aldo Leopold Legacy Center Baraboo, WI 11,900 -2.02

Audubon Center at Debs Park

Los Angeles, CA 5,020

Challengers Tennis Club

Los Angeles, CA 3,500 -0.0955

Environmental Tech. Center, Sonoma State

Rohnert Park, CA 2,200 -1.47

Hawaii Gateway Energy Center

Kailua-Kona, HI 3,600 -3.46

IDeAs Z2 Design Facility San Jose, CA 6,560 -0.00052

Oberlin College Lewis Center Oberlin, OH 13,600 -4.23

Science House St. Paul, MN 1,530 0

A Pathway to Net Zero Energy:The Commercial Building

Initiative

• Goal– Market-ready, net-zero energy commercial buildings no

later than 2025

• Public-Private Partnerships– Drive efficiency gains– Promote improved technology– Accelerate commercialization of advanced building

technologies

Commercial Building Initiative

CBI: Technology Push vs. Market Pull

Commercial Building Energy Alliances

• Retailer Energy Alliance (February 2008)– 32 members representing 2.28B sq. ft.

• Commercial Real Estate Energy Alliance (April 2009)– 39 members representing 5.24B sq. ft.

• Hospital Energy Alliance (April 2009)– 21 members representing 319M sq. ft.

• Higher Education Energy Alliance (forming Steering Committee now; launch expected Q1 2010)

• State and Municipal Energy Alliance (2010)

Informal associations among building owners and operators who want to reduce energy consumption

Key Alliance Activities• Technology Procurement Projects

– LED Lighting– Rooftop HVAC– Parking Garage Lighting

• Supplier Summits – HVAC, Refrigeration, and Controls, Jan ‘08 & ’09– Lighting and Controls, May ‘09

• Technology Evaluation – Building owner directed research

and screening• Efficiency Standardization and Tools

– Commercial Lighting Solutions – HVAC Solutions/Central– Commercial Refrigeration Solutions

National Accounts

• DOE national labs teamed with 23 companies to:– Build one new building at 50%

less energy than Standard 90.1

– Retrofit at least one existing building at 30% less energy

• Labs provide technical assistance to biggest names in retail, commercial real estate, and financial sectors

Companies from the private sector working with national laboratories to achieve significant,

unprecedented building energy savings.

An Example

ZEB involves Prudent Choices…• Reduce Loads

– Envelope and orientation to reduce loads» Insulation, air barrier & windows

– Envelope and orientation to meet loads» Daylighting, passive solar heating, and natural

ventilation– Lighting design

» Daylighting– Plug loads

» Design vs. owner loads• Match Equipment to Loads

– Climate-specific HVAC designed for the remaining loads• Make Sure the Building Works

– Design quality in, and Commissioning• Constant Evaluation• Keep It Simple• Choose Site Specific Renewable Generation

Carefully

Energy & Cost Optimization

Starting Point

Minimum Cost Point

Cost Neutral Point

~3,000 Simulations

Optimization Result• A Building Design that:

– Satisfies the owner’s business criteria• (e.g., positive NPV on a 3-year lifecycle cost basis)

– Meets or exceeds energy savings objectives• (e.g., uses 50% less energy than a 90.1-2004 compliant building)

Closing Thoughts• Zero is possible• Zero takes a coordinated effort with the owner, architect, and engineering team

• The little things make the difference in getting to zero (as you get to zero, small items become significant)

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

• The solution is not bigger supplies

Thanks!Commercial Building Initiativecommercialbuildings.energy.gov

NREL’s Commercial Buildings Research Projectswww.nrel.gov/buildings/commercial.html

Greg StarkTeam Lead, National Accounts ProjectAdvanced Commercial Buildings ResearchNational Renewable Energy LaboratoryGreg.Stark@nrel.gov