Does Net Zero Design LEED to Zero Cost? Presented to Society for College and University Planning July 12
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Learning Outcomes 1. Identify building candidates at the master plan level to optimize net zero design options. 2. Define performance goals that drive design toward net zero. 3. Educate building occupants, facilities maintenance, and administration to facilitate the shift to a net zero paradigm. 4. Incorporate post-occupancy evaluations, measurement, verification, and recommissioning to ensure a successful outcome.
Expanding Number of Zero Net Initiatives
• University of California Climate Neutral Action Plans – UCSB Student Services / Division of Student Affairs ZNE Initiatives
• • • •
California State University Sustainability Building Practices LACCD’s Sustainable Building Program DSA Grid Neutral Schools Program California Public Utilities ZNE Non-Residential Goals – All new construction ZNE by 2030 – 50% of existing buildings ZNE by 2030 • Architecture 2030 • AB32 Global Warming Solutions Act
California Warming
Anticipated Climate Changes in CA
Plausible Increases in Los Angeles Average Temperatures IPCC Scenario A2
IPCC Scenario B1
Based on 2009 Scenarios Project climate modeling http://www.climatechange.ca.gov/adaptation/index.html
Trends in Building Energy Use National Historical Data for Non-Residential Buildings
Plug loads are driving increasing energy use
Trends in Building Energy Use
Trends in Building Energy Use
Energy Prices Rises and Volatility in California
Electricity and gas prices have risen at an annualized rate of 5-6% since 1970
Post Occupancy Performance Certification New ASHRAE Building EQ Label • In the near future all green building certification programs will have some form of post-occupancy performance evaluation • LEED – Disclosure of building performance • Required for all certified projects • Must allow USGBC access to utility data for at least 5 years
LEED NC Version 3 – Energy Performance Credits • Achieving ZNE provides significant opportunity for LEED Credits
100 80
LEED NC Points
• EAc1 Optimize Energy Performance (19) • EAc2 Optimize On-Site Renewable Energy (7) • EAc3 Enhanced Commissioning (1) • EAc5 Measurement and Verification (1) • EAc2 Increased Ventilation (1) • EAc7.1 Thermal Comfort – Design (1) • EAc8.1 Daylight and Views – Daylight (1) • ID ZNE (1) • RP EAc2, EAc8.1 (2)
60 40
34 Points
20 0
LEED NC
ZNE
Integrated Design Process Post-Occupancy Performance Climate Analysis
Whole Building Models
Detailed Modeling and Design Performance Goals
Shoebox Modeling
Parametric Analysis
Pushing the Envelope
Low Energy Systems
Energy Savings at the Least Cost
ZNE
Building Life Time Cost
Transition to on-site renewables
Minimum LCC
Energy Savings
100%
• Energy efficiency and conservation should come first • Add on-site renewables when cost analysis shows it is cheaper than more aggressive energy efficiency
Energy Savings at the Least Cost
• Simulation tools are available which find the least cost curve • Example here is from BeOpt developed by National Renewable Energy Laboratory • Output is a set of alternative ‘measure packages’ for achieving ZNE
Lifecycle Cost Example • What is the net present value of eliminating utility bills? • How much capital investment is justified to achieve ZNE? • Hypothetical new building in California: • • • • • • • • •
100,000 sf Construction cost of $300/sf Energy use intensity of 40 kBtu/sf/yr 60% electricity and 40% gas consumption Electricity cost of $0.14/kWh and gas cost of $1.00/therm Cost of photovoltaics is $5/watt Study period of 25 years Real discount rate of 3% ZNE achieved using energy efficiency and rooftop PV
Return on Investment The higher the increased project cost to achieve ZNE the lower the rate of return To achieve an ROI of 3% the cost of ZNE would need to be approximately $5.6M
Assumptions: 50,000 sf building, 60% electricity, 40% gas, design costs are 6% of construction costs, construction cost is $400/sf, ZNE design time is 1,000 hours, time period is 25 years, discount rate is 25 years, energy escalation based on DOE assumptions
Efficiency vs On-Site Renewables
Assuming a budget of $5.6M for PV, the building must have an EUI of 16 kBtu/sf/yr to achieve ZNE
The Path to ZNE Making ZNE financially attractive is possible through aggressive levels of energy efficiency None monetized benefits should also be considered: -Healthy high quality spaces -Improved productivity -Employee recruitment and retention -Hedge against rising energy costs
Assumptions: 50,000 sf building, 60% electricity, 40% gas, design costs are 6% of construction costs, construction cost is $400/sf, ZNE design time is 1,000 hours, time period is 25 years, discount rate is 25 years, energy escalation based on DOE assumptions
Physical Limitations for Building Integrated PV Single Story Building Roof EUI (kBtu/sf/yr) 200
PV PV
150
100
PV Solar Budget
50
0
Building Consumption=40 kBtu/sf/yr PV Generation=60 kBtu/sf/yr PV Covers 50% of roof area
Grid Neutral Net Zero Energy EUI = 25 EUI = 40
Physical Limitations for Building Integrated PV Two Story Building Roof EUI (kBtu/sf/yr) 200
PV 150
100
PV Solar Budget
50
0
Building Consumption=40 kBtu/sf/yr PV Generation=60 kBtu/sf/yr PV Covers 50% of roof area
Grid Neutral Net Zero Energy EUI = 25 EUI = 40
Physical Limitations for Building Integrated PV Three Story Building Roof EUI (kBtu/sf/yr) 200
PV 150
100
PV Solar Budget
50
0
Building Consumption=40 kBtu/sf/yr PV Generation=60 kBtu/sf/yr PV Covers 50% of roof area
Grid Neutral Net Zero Energy EUI = 25 EUI = 40
the PlugPerformance Loads Post Watch Occupancy
Owner/PM
A/E
O&M The Commissioning Process
GC
the PlugPerformance Loads Post Watch Occupancy
• Commissioning • Conduct design reviews • Verify Training for Operators and Occupants.
• Perform a Post Occupancy Review by 10 months after completion.
• Measurement and Verification • Develop M&V Plan • Measure actual energy use • Verify actual versus predicted energy cost
San Diego Community College District Propositions S and N
San Diego Community College District Overview Propositions S and N Construction Bond Program
$1.555 billion construction bond program provides for 80+ projects at City, Mesa and Miramar Colleges, and six Continuing Education campuses:
State of the art teaching and learning facilities Major renovations and modernizations Campus-wide infrastructure projects Green Building Policy
25
San Diego Community College District Propositions S and N
Environmental Sustainability Policy
Environmental sustainability is an essential goal of the District. Global warming, diminishing resources and escalating costs of energy and rubbish disposal require that management at all levels focus on the efficient and effective use of energy and resources.
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San Diego Community College District Propositions S and N
Green Building Policy • The Board of Trustees is committed to environmental stewardship as a fundamental operational objective and integral to fulfilling our educational mission. • The Board recognizes its fiscal responsibility to use taxpayers' dollars wisely for the best long-term, long-range investment. • The goal of this policy is to provide working and learning environments that are: – – – – – 27
Efficient in use of energy, material and water Easy to maintain and operate Thermally, visually and acoustically comfortable and healthy Safe and secure Sited in an environmentally responsible manner.
San Diego Community College District Propositions S and N
Green Building Policy: Goals Exceed Title 24 of California Code of Regulations energy efficiency standards by at least 10%.
10% of the energy utilized by the project must be renewable with at least 5% generated on site.
Divert at least 75% of construction and demolition debris from landfills.
Pursue formal LEEDTM certification with LEEDTM Silver as a minimum standard; Gold or higher where applicable.
San Diego Community College District Propositions S and N
Green Building Policy: Methodology •Incorporate life-cycle costing that includes initial construction costs, operating costs, maintenance repair and replacement costs •Integrated systems design
•Perform commissioning and facility performance evaluations
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San Diego Community College District Propositions S and N
Total Cost of Ownership Example • 50 year design life • 100,000 square foot classroom building • Design and construction cost - $30 million • Capital Renewal: 2% of current replacement value (APPA benchmark)
• O&M Budget $5.69/square foot • Inflation: 3%
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San Diego Community College District Propositions S and N
Savings in O&M and Capital Renewal
Total Cost of Ownership
11%
53% 36%
Save 5% in Cap. Renewal
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Save 10% in O&M
D&C: Cap.R: O&M: Total:
$30M $101M $149M $280M
Savings Total NPV $5M $1.1M $15M $3.4M $20M $4.4M
San Diego Community College District Propositions S and N
BIM Standards
http://www.sdccdprops-n.com/BUILDING%20STANDARDS/SDCCD_BIM_Standards_Ver01.pdf
San Diego Community College District Propositions S and N
BIM: Sustainable Design BIM was used to optimize efficiency by making sure that at key times of the year the panels on a classroom building with sloped roofs would not be in the shade. This example shows shading on the building in the afternoon on December 1st.
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San Diego Community College District Propositions S and N
Miramar College Parking Structure & Police Station • Will be first LEED Platinum project for a
community college in San Diego County • Passive cooling & lighting systems • Green roof and green screen • Reclaimed water • Solar chimney
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San Diego Community College District Propositions S and N
Miramar College Parking Structure & Police Station
SOLAR CHIMNEY
Monthly Heating, Cooling and Fan Energy (kBtu/sf)
2.50 Mechanical System Only 2.00 Mixed Mode Natural Ventilation System
1.50 1.00 0.50 0.00
GREEN WALL
Metro Station
Bus Stop
Student Union Project Site
Bus Stop
NORTH
CAMPUS PLAN
SUSTAINABLE STRATEGIES: -MIXED MODE HVAC -NIGHT FLUSHING -EXTERIOR SHADING -DAYLIGHTING -PHOTOVOLTAICS
Operable Windows For Natural Ventilation Will Support Night-Flushing
Perspective Views Of Concrete Frame
Exposed Concrete Frame Works As Thermal Mass: It stores The Heat During The Day, Night-Flushing Cools It Down Over Night
Concrete structural system SUSTAINABILITY
Large North Facing Glass Walls
Borrowed Light Through Extensive Interior Glazing.
North Facing Roof Mounted PV Panels Skylights
Skylight With Bench-Seating Section Cut: Three Story Volume
Sunshade Structures On South and East Facing Glazing
Clerestory Skylight
Daylighting strategies
SUSTAINABILITY
Daylight In Multi Purpose Space
Ecotect Model With Daily Sun Path
Light monitors angled and oriented correctly so that no direct sun enters the space Analysis of Initial Design
Analysis of Corrected Design
SUSTAINABILITY
SUSTAINABLE STRATEGIES: -EXTERIOR SHADING -DAYLIGHTING -PHOTOVOLTAICS
Exterior sun shade structure - prevents heat gain, glare Interior light shelf -reflects daylight deeper into the room
ORIGINAL SUNSHADE
REVISED SUNSHADE WITH LIGHT-SHELF
ATRIUM DESIGN DAYLIGHT FACTOR FOR 1ST FLOOR
SOUTH FACING SKYLIGHT, WITH PV INTER LAYER
CLERESTORY DESIGN
SOLATUBE APPLICATION - BRING DAYLIGHT TO FIRST FLOOR ISSUES: - ADDITIONAL SHAFT SPACE - FIRE RATED SHAFT, NEED FIRE DAMPER
UNIVERITY OF SANTA BARBARA RECREATION CENTER Rec Center 1 Pavillion Gym Rec Center 2 Multi-Activity Center
Rec Center 1 Activities Gym, Weight Rooms, Squash/Racketball Courts and Offices
4,000,000 Pool Heating Pool Pumping
3,500,000
Rec 2 building Outdoor Lighting Rec 1 building Outdoor Lighting Sports Lighting
Pool Closed
2,500,000
2,000,000
1,500,000
1,000,000
500,000
kBtu
00 9 2/ 1/ 2
20 08 10 /1 /
00 8 6/ 1/ 2
00 8 2/ 1/ 2
20 07 10 /1 /
00 7 6/ 1/ 2
00 7 2/ 1/ 2
20 06 10 /1 /
00 6 6/ 1/ 2
00 6 2/ 1/ 2
20 05 10 /1 /
00 5
0 6/ 1/ 2
Site Energy (kBtu)
3,000,000
SUSTAINABLE STRATEGIES: -NATURAL VENTILATION -RADIANT FLOOR -DAYLIGHTING -EXTERIOR SHADING -PHOTOVOLTAICS -SOLAR THERMAL SPACE HEATING
Rolling 12 Month Energy Use Intensity (kBtu/sf/yr)
120
Energy Consumption for Existing Berkeley Libraries West
North
South
Central
Claremont
100
80
60
40
20
EUI Performance Design Goal = 20 kBtu/sf/yr
0
Sep-07
Dec-07
Mar-08
Jun-08
Sep-08
Dec-08
Mar-09
Jun-09
Sep-09
WIND DRIVEN NEGATIVE PRESSURE DISTRIBUTION AROUND THERMAL CHIMNEY
INTERIOR DISTRIBUTION OF FRESH AIR
Thank You
Questions?
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