THE PATH TO NET-ZERO Richard Graves, AIA -...

source

assimilation

storage

distribution

· Effectiveness as end goal · Symbiosis· Closed-loop system· Multiple pathways

· Within renewal capacity· Integrate with natural processes

REGENERATIVE SYSTEMS

Hea ng, 42%

Cooling, 5%

Fans, Pumps, and Controls, 11%

Lights, 17%

Equipment, 25%

Energy Grid

Solar Energy Input579,105 MWh / year

Pre-Settlement ConditionEastern Deciduous Forest

Solar Energy Reected, Absorbed & Released 550,150,282 kWh/year95%

Solar Energy Used by Photosynthesis26,059,750 kWh/year

4.5%

Sources: Lloyd Center: Sustainable Urban Design+Catalyst ProjectMN Solar Suitability Analysis - http://solar.maps.umn.edu/app/

Total Energy Use:60,984 MWh / year

Code-Based Buildings - ASHRAE 90.1 20102015 Energy Grid

Wind Generated - 15%

Hydro Generated - 6%

Biomass Generated - 4%

Nuclear Generated - 30%

Natural Gas Generated - 8%

Coal Generated - 37%

Electricity Imported39,640,124,749 kWh / year

65% of Total Energy

Natural Gas Imported21,344,682,557 kWh / year

35% of Total Energy

Built Up Area:Low Density Housing - 534,000 2Med Density Housing - 1,296,000 2High Density Housing - 570,000 2Civic - 50,000 2Retail and Mixed Use - 375,000 2Ins tu onal - 194,000 2

Total - 3,019,000 2

Total Energy Use:60,984 MWh / year

Code-Based Buildings - ASHRAE 90.1 20102030 Energy Grid

Wind Generated - 25%

Hydro Generated - 2%

Biomass Generated - 0%

Nuclear Generated - 28%

Natural Gas Generated - 22%

Coal Generated - 15%

Electricity Imported39,640,124,749 kWh / year

65% of Total Energy

Natural Gas Imported21,344,682,557 kWh / year

35% of Total Energy

Solar Generated - 8%

Built Up Area:Low Density Housing - 534,000 2Med Density Housing - 1,296,000 2High Density Housing - 570,000 2Civic - 50,000 2Retail and Mixed Use - 375,000 2Ins tu onal - 194,000 2

Total - 3,019,000 2

Total Energy Use:26,121 MWh / year57% Reduction

SB2030 80% Better Buildings2030 Energy Grid

Wind Generated - 25%

Hydro Generated - 2%

Biomass Generated - 0%

Nuclear Generated - 28%

Natural Gas Generated - 22%

Coal Generated - 15%

Electricity Imported16,978,730 kWh / year

65% of Total Energy

Natural Gas Imported9,142,392 kWh / year

35% of Total Energy

Solar Generated - 8%

Built Up Area:Low Density Housing - 534,000 2Med Density Housing - 1,296,000 2High Density Housing - 570,000 2Civic - 50,000 2Retail and Mixed Use - 375,000 2Ins tu onal - 194,000 2

Total - 3,019,000 2

PV Electricity Poten al: 15,219,152 kWh / year100% of Roof Area89% of Electricity Demand58% of Total Energy Demand

Wind Generated - 25%

Hydro Generated - 2%

Biomass Generated - 0%

Nuclear Generated - 28%

Natural Gas Generated - 22%

Coal Generated - 15%

Electricity Imported1,759,578 kWh / year

7% of Total Energy

Solar Generated - 8%

Natural Gas Imported9,142,392 kWh / year

35% of Total Energy

Total Energy Use:26,121 MWh / year

SB2030 80% Better Buildings2030 Energy Grid + PV RoofsBuilt Up Area:Low Density Housing - 534,000 2Med Density Housing - 1,296,000 2High Density Housing - 570,000 2Civic - 50,000 2Retail and Mixed Use - 375,000 2Ins tu onal - 194,000 2

Total - 3,019,000 2

PV Electricity Poten al: 15,219,152 kWh / year100% of Roof Area58% of Total Energy

Renewable GeneratedSolar PowerWind Power

Hydro Power

Electricity Imported10,901,970 kWh / year

42% of Total Energy

Total Energy Use:26,121 MWh / year

SB2030 80% Better BuildingsRenewable Energy Grid + PV RoofsBuilt Up Area:Low Density Housing - 534,000 2Med Density Housing - 1,296,000 2High Density Housing - 570,000 2Civic - 50,000 2Retail and Mixed Use - 375,000 2Ins tu onal - 194,000 2

Total - 3,019,000 2

Net-ZeroPV Electricity Poten al: 10,448,449 kWh / year55% of Roof Area, 100% Of Demand40% of Total Energy

Net-Posi vePV Electricity Poten al: 15,219,152 kWh / year100% of Roof Area, 145% of Demand4,770,703 kWh back to grid, electricity for 491 single family homes

Hea ng and Cooling Energy Generated by Aquifer Thermal Energy Storage System

15,672,673 kWh / year60% of Total Energy

Total Energy Use:26,121 MWh / year

SB2030 80% Better BuildingsOn-Site Renewable EnergyBuilt Up Area:Low Density Housing - 534,000 2Med Density Housing - 1,296,000 2High Density Housing - 570,000 2Civic - 50,000 2Retail and Mixed Use - 375,000 2Ins tu onal - 194,000 2

Total - 3,019,000 2

Code Buildings2015 Energy Grid

Ford PlantHydroelectric

Power

Pre-Settlement Code Buildings2030 Energy Grid

SB2030 80% Buildings2030 Energy Grid

SB2030 80% BuildingsPV Roofs +

2030 Energy Grid

SB2030 80% BuildingsPV Roofs +Renewable Energy Grid

SB2030 80% BuildingsOn-Site Renewables

Renewable Energy Input

Solar Energy Used:5%

Thermal Storagein Ground Solar Energy Used:

0% Hydro Energy Used:

100%

Solar Energy Used:8%

Solar Energy Used:8%

Solar Energy Used:58%

Solar Energy Used:58%

Renewable Energy Used:

42%

Solar Energy Used:40%

Extra Solar Energy Produced:

+15%

ATES Energy Used:60%

OFFICE PROTOTYPE

RETAIL

OFFICE

ENVELOPE: Tightly insulated walls (R42), windows (U-0.24), and roof (R35). Insula�on values exceed building code by 30-55%.18.9 kBtu/sf / year EUI44% reduc�on in energy demand969 metric tons CO2 saved

HUMAN POWERED LIVING: Open and a�rac�ve stair encourages occupants to use stairs instead of electricity-driven elevators.50% reduc�on in elevator trips can save 6,701 kWh per year, equivalent to 4.6 metric tons of CO2

HVAC: Ground source heat pump �ed into aquifer thermal energy storage. Provides hea�ng and cooling using deep underground aquifer.

HUMAN POWERED LIVING: Dense neighborhood with frequent pedestrian and bicycle paths encourages residents and building users to leave cars behind.

INTERNAL LOADS: Ligh�ng power densi�es are limited to 0.4 wa�s / �2.Equipment power densi�es limited to 0.8 wa�s / �2.44% reduc�on in ligh�ng wa�s / �2 from code20% reduc�on in equipment wa�s / �2 from typical building

GREY WATER REUSE: Collect and treat grey water from sinks and use it to ush toilets and urinals. Excess grey water will be used for irriga�on.67,258 gallons of grey water produced each month100% of demand for grey water met

RAINWATER CAPTURE: Collect rainwater from roof, treat and store in cistern for use in building.48,500 gallons of rain water collected each month72% of demand for potable water met

SOLAR ARRAY: Renewable energy generated on site using two-way solar array that maximizes produc�on poten�al.1,394,650kWh produced yearly92% of elec�city demand met962 metric tons CO2 saved

PROGRAM: A mixed-use building with retail and office program.26,865 square feet of retail150,000 square feet of office

IMPROVED CASE - BY THE NUMBERSMulti Family and Retail

BUILDING DETAILS219,096 Total SF7,658 Retail SF on 1st Floor187 Units on 1st-6th Floor37,073 Roof SF

ENERGY PERFORMANCE38.2 kBtu/sf/yr EUI511,870 kW Photovoltaic Array

WATER USE35% of Potable Water Demand met by Rainfall18.13 Gallon Demand per Person per Day

VALUE$000 / SF Baseline$000 / SF Net Zero Energy$000 / SF Net Zero Water$000 / SF Living Building Challenge

MAJOR DESIGN STRATEGIES

53% Potable Water Demand Reduction

Rainwater capture & Greywater reuse

Increased R Values for Walls & Roof

Improved Glazing Performance

Lighting Power Densities reduced 20%

Lights dim when daylighting reaches 45fc

Orientation optimized for performance

RESIDENTIAL PROTOTYPE

STORAGE

RETAIL

RESIDENTIAL

RESIDENTIAL

SOLAR ARRAY: Photovoltaic panels covering the roof area generate 18% of the building’s energy demand.

BUILDING ENVELOPE: Increased insula on in exterior walls (R60) and roof (R80) and improved glazing (U-0.24) reduce energy demands throughout the year.

PROGRAM: Mixed use Residen al and Retail 171,459 SF of Residen al Space7,658 SF of Retail

HUMAN POWERED LIVING: Centrally-located stairs provide views of surrounding neighborhood and encour-age users to use stairs rather than elevator.

HVAC: Ground source heat pump system uses year-round average underground temperature to coolor warm interior spaces.

RAINWATER CAPTURE: Roo op rainwater collec on to treat and used to meet 35% of monthly potable water demand

HUMAN POWERED LIVING: Dense neighborhood with frequent pedestrian and bicycle paths encourages residents and building users to leave cars behind.

INTERNAL LOADS: Reduc on in ligh ng power densi es and equipment power densi es by 20% reduces EUI by 3 kBtu/sf/yr.

GREYWATER REUSE: Basement cisterns collect greywater from within building to reuse for toilets and urinals. Able to provide for 100% of greywater demand.

Sources: http://www.johnweeks.com/bridges/pages/lockdam01.htmlPhoto credit: JERRY CIARDELLI, ERDAHL AERIAL PHOTOS

Hydro Energy Input14.4 MWh / year

Ford Plant1925-2011

Built Up Area:

Total - Approx. 2,000,000 2

St. Paul Ford Site: Twin Cities Assembly Plant to a 21st Century Community

- Opened in 1925, built in St. Paul on the promise of cheap hydropower.- The Ford Dam, part of Lock and Dam No. 1, was completed in 1929 and provided 14.4 Mw of electricity. - Glass was made from 1926 to 1959, and was produced from silica mined on site. The mining tunnels still exist below grade. - Closure of the plant was announced in April of 2006, and the last vehicle was produced on December 16, 2011.

- Site clean up and environmental testing is ongoing to prepare the property for future development. - St. Paul Mayor Chris Coleman has emphasized a desire for “net-zero” community that includes housing, commercial space, park space, and transportation options.

DEMAND: 197,822 kWh / year

ONE STORY OFFICE

PV PRODUCTION: 649,745 kWh / year

PV ARRAY MEETS

TOTAL ENERGY DEMAND328%

DEMAND: 395,645 kWh / year

TWO STORY OFFICE

PV PRODUCTION: 649,745 kWh / year

PV ARRAY MEETS

TOTAL ENERGY DEMAND164%

DEMAND: 593,468 kWh / year

THREE STORY OFFICE

PV PRODUCTION: 649,745 kWh / year

PV ARRAY MEETS

TOTAL ENERGY DEMAND109%

DEMAND: 791,291 kWh / year

FOUR STORY OFFICE

PV PRODUCTION: 649,745 kWh / year

PV ARRAY MEETS

TOTAL ENERGY DEMAND82%

DEMAND: 989,114 kWh / year

FIVE STORY OFFICE

PV PRODUCTION: 649,745 kWh / year

PV ARRAY MEETS

TOTAL ENERGY DEMAND66%

EUI - 22.5 kBtu/sf/year EUI - 22.5 kBtu/sf/year EUI - 22.5 kBtu/sf/year EUI - 22.5 kBtu/sf/year EUI - 22.5 kBtu/sf/year

DEMAND: 314,378 kWh / year

ONE STORY RESIDENTIAL

PV PRODUCTION: 724,581 kWh / year

PV ARRAY MEETS

TOTAL ENERGY DEMAND230%

DEMAND: 628,757 kWh / year

TWO STORY RESIDENTIAL

PV PRODUCTION: 724,581kWh / year

PV ARRAY MEETS

TOTAL ENERGY DEMAND115%

DEMAND: 943,135 kWh / year

THREE STORY RESIDENTIAL

PV PRODUCTION: 724,581 kWh / year

PV ARRAY MEETS

TOTAL ENERGY DEMAND76%

DEMAND: 1,257,514 kWh / year

FOUR STORY RESIDENTIAL

PV PRODUCTION: 724,581 kWh / year

PV ARRAY MEETS

TOTAL ENERGY DEMAND58%

DEMAND: 1,571,892 kWh / year

FIVE STORY RESIDENTIAL

PV PRODUCTION: 724,581 kWh / year

PV ARRAY MEETS

TOTAL ENERGY DEMAND46%

EUI - 32.0 kBtu/sf/year EUI - 32.0 kBtu/sf/year EUI - 32.0 kBtu/sf/year EUI - 32.0 kBtu/sf/year EUI - 32.0 kBtu/sf/year

2

31

0 0.5 1 1.5 2 2.5 3 3.5 4

Small OfficeMedium Office

Large Office

Stand Alone RetailStrip Mall Retail

Supermarket

Primary SchoolSecondary School

HospitalOutpatient Health Care

Full‐Service RestaurantQuick‐Service Restaurant

Small HotelLarge Hotel

Warehouse

Mid‐Rise ApartmentHigh‐Rise Apartment

Prototype OfficePrototype Residential

Square Feet

Build

ing 

Use

Area Powered Per Sq.ft. of PV in St. Paul, MN

1 sq.ft. PV Panel

3.3 sq.ft. Office area

1 sq.ft. PV Panel

2.3 sq.ft. Residential area

1 sq.ft. PV Panel

3.3 sq.ft. Office area

1 sq.ft. PV Panel

2.3 sq.ft. Residential area

Center for Sustainable Building Research Center for Sustainable Building Research

From Regenerative Design for Sustainable Development, John Tillman Lyle, 1994

Office Prototype

Design Strategies

Load ProfilesOffice - Code Residential- CodeOffice - Improved Residential - Improved

Rendering Key Plan

Design Strategies

Residential Prototype

1. Office Building Prototype

2. Residential Building Prototype

3. Residential Building Prototype Back Yard with Urban Agriculture

On December 2011, Ford Motor Company closed its Twin Cities Assembly Plant, which had operated in Saint Paul for over 80 years. The 157 acre property is located on the east bank of the Mississippi River, surrounded by a vibrant residential community and business district. The redeveloped Saint Paul Ford site is envisioned to be a global model of ingenuity, cutting edge sustainability, and vibrant, transit-oriented urban living that attracts the generations of tomorrow and today. This project will build on Saint Paul’s demonstrated success of initiatives to improve energy efficiency, reduce fossil fuel use and expand renewable energy generation, but will take it to the next level by striving for a net-zero community. The underpinning of this requires a site-wide,integrated energy system that incorporates renewable energy sources and design efficiencies to reduce demand and reuse energy. The site will be redeveloped from scratch starting in 2018 with installation of new utilities, streets, sewers and water providing a unique opportunity to design an integrated energy system.

A fundamental understanding of the energy goals for the site, demonstrated feasibility and an implementation framework were analyzed for three options to achieve a resilient and sustainable energy system. All options assumed very energy efficient buildings with performance guided by the Sustainable Buildings 2030 program the state of Minnesota adapted from Architecture 2030. The pathway to a Net Zero community is an integrated energy design concept that could serve as a model of future sustainable development.

This chart describes the relationship between energy use intensity and photovoltaic panel production potential in St. Paul, Minnesota. Various building uses are listed on the left, and the square feet of building powered by 1 square foot of PV panel is indicated by the bar. The building type highest floor-to-pv ratio is warehouse, at 3.6 sq.ft. of floor to 1 sq.ft. of PV. The building type with the lowest ratio is supermarket, at 1.25 sq.ft. of floor to 1 sq.ft. of PV. These EUI numbers are based on SB2030 80% reduction targets established for each use type.

This parametric study examines the relationship between one square foot of PV panel and the area of building able to be powered by it. The PV generated numbers calculated were established with NREL’s PV Watts software and assume a premium, roof mounted module with an 18% efficiency. This results in 73.8 kBtu (21.63 kWh) per square foot per year potential to be generated. 100% of the roof area is assumed to be available for PV generation - 33,500 ft2 for the residential building and 30,000 ft2 for the office building. The building energy use values are the result of the energy efficiency measures established above. The residential building consumes 32.0 kBtu/ft2/year (9.38 kWh/ft2/year). The office building consumes 22.5 kBtu/ft2/year (6.59 kWh/ft2/year).

THE PATH TO NET-ZERO Richard Graves, AIA - CSBRLiz Kutschke - CSBR

CARRYING CAPACITY AND NET ZERO DEVELOPMENTATES System

PV Panels

Efficiency, 57%

Hea�ng,

4%

Cooling, 5%

Fans, Pumps, and Controls, 6%

Lights, 8%

Equipment, 14%

Hot Water, 6%

Hea ng, 30%

Cooling, 5%

Fans, Pumps, and Controls, 12%

Lights, 3%

Equipment, 50%

Energy Grid

ATES System

PV Panels

Efficiency, 66%Hea�ng ,

3%

Cooling,

2%

Fans, Pumps, and Controls, 5%

Lights, 12%

Equipment 6%

Hot Water, 7%

Net-ZeroPV Electricity Poten al: 10,448,449 kWh / year55% of Roof Area, 100% Of Non-Hea ng and Cooling Demand40% of Total Energy

Net-Posi vePV Electricity Poten al: 15,219,152 kWh / year100% of Roof Area, 145% of Non-Hea ng and Cooling Demand4,770,703 kWh back to grid, electricity for 491 single family homes

Hea ng and Cooling Energy Transferred by Aquifer Thermal Energy Storage System

15,672,673 kWh / year60% of Total Energy

Total Energy Use:26,121 MWh / year

SB 2030 80% Better BuildingsOn-Site Renewable EnergyBuilt Up Area:Low Density Housing - 534,000 2Med Density Housing - 1,296,000 2High Density Housing - 570,000 2Civic - 50,000 2Retail and Mixed Use - 375,000 2Ins tu onal - 194,000 2

Total - 3,019,000 2

source sinks

efficiency waste

inputs outputs

consume

EXISTING THROUGHPUT SYSTEMS

· Efficiency as end goal · Degenerative linear flows