Current Situation and Actions for nZEB in Japan

Hideharu Niwa NIKKEN SEKKEI Research Institute, JapanChair of Committee on Guideline for Design of nZEB in SHASE*

REHVA BRUSSELS SUMMIT CONFERENCE (2017.11.14)

*The Society of Heating, Air-Conditioning and Sanitary Engineering

Gyo Onishi TAISEI CORPORATION, JapanObserver of Committee on Guideline for Design of nZEB in SHASE*

1

Background of nZEB in Japan

1. NZEB (Net Zero Energy Building) has become recognized to be important for energy conservation and global warming prevention.

2. In Japan, after the East Japan Great Disaster, the need of self-sufficiency of energy has been recognized from the viewpoint of energy security.

3. Definition and Evaluation method of nZEB is not so clear that design method of nZEB is not yet established.

Discussion on Definition and Evaluation Method of NZEB in SHASE of Japan from 2012

2

Continuous Committee on ZEB in SHASE of JAPAN

#1 Committee for Definition of ZEB 2012.4-2015.3・Research on worldwide trend of ZEB・Research on advanced trial for ZEB in Japan・Discussion on definition and evaluation of ZEB・Case study on definition and evaluation of ZEB ⇒Guideline for Definition and Evaluation of ZEB

#2 Committee on Feasibility of ZEB 2015.4-2017.3・Research on best practice in domestic and overseas・Feasibility study on realizing ZEB using simulation・Extraction elemental for technologies for ZEB realizing

#3 Committee on Guideline for Design of ZEB 2017.4-・Discussion on evaluation of elemental technologies for ZEB・Study on regarding definition, social value, and so on ZEB・Integration of elemental technologies for realizing ZEB ⇒Guideline for Design of ZEB, including pamphlet

3

Today’s 5 Topics on nZEB

1. Design Approach for nZEB in Japan

2. Definition and Evaluation Method of nZEB

3. Research on Best Practice of nZEB

4. Guideline and Pamphlet for Design of nZEB

5. Future Tasks for Spread of nZEB in Japan

4

Design Methods of Traditional Japanese Architecture

Pic.1 Traditional Japanese House “京町屋”

Design Methods for Saving Energy and Resource 1. Enjoying the Fluctuation of Indoor Environment2. Strict Load Control3. Use of Natural Energy4. Use of Natural Materials

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Fig.1 Example of Passive Design for Eco-logical Building in Japan

Shading of Sunlight Purging of Inner Heat

Natural Ventilation

Radiation Cooling

Well Water Cooling

For comfortable summer

Completed in 1995

Design Methods for Eco-logical Buildings in Japan

6

Design Methods of Japanese Modern Architecture

Natural Lighting Natural Ventilation

Examples of Natural Energy Using of Modern Architecture

in 1960’s in 1980’s

A big atrium inside to encourage natural ventilation by chimney effect

Deep shelf to intake natural sunlight

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Design Methods of Sustainable Buildings in Japan

Solar collector PV

Light shelf

Atrium Meeting room

Lobby

Project room

Entrance

Cooling and Heating Trench

Wind PowerLouver

Summer, Mid-season: Natural ventilation

Winter: Heat recovery

1. Natural ventilation2. Day lighting3. Use of underground heat

4. Photovoltaic power 5. Solar heat collector6. Wind power

Passive and Active Design Methods are combined

Completed in 2002

Fig.2 Example of Passive and Active Design for Typical Sustainable Building

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Approach to net Zero Energy Building

0

200

400

600

800

0 200 400 800 1000 1200 1400 1600

Energy Consumption　[MJ／a･㎡]

Gen

era

ted E

nerg

y　 [

MJ／

a･㎡

]

600

net Zero Energy net 200 net 400

Reference BuildingLow Energy Building

nearlyNet Zero Energy Building

Net Zero Energy

Energy Consumption

Ener

gy G

ener

atio

n

Fig.3 Approach to Net Zero Energy Building

X

y

Traditional Japanese House

Large Energy Increase

Passive and Active Approach for Energy Saving

RenewableEnergyGeneration

9

LoadReduction

Optimizationof Indoor

Environment

Use ofNaturalEnergy

Optimizationof Outside

Environment

Use ofUnutilized

Energy

High EfficiencySystem

EnergyManagement

Use ofRenewable

Energy

#1 Passive Design Methodsfor Low Energy Building

#3 EnergyManagementMethod

Design Approach to Net Zero Energy Building

#2 Active Design Methodsfor Low Energy Infrastructure

Fig.5 Design Approach to Net Zero Energy Building

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PV（太陽電池）

光庭風庭

熱交換器

１．Optimization of Outside Environment1.1 Location of Building

Ventilation, Location of Building1.2 Outside Environment Planning

Green and water, Surface Material

２．Optimization Indoor Environment2.1 Thermal Environment

Temperature, Humidity, Radiation2.2 Lighting Environment

Optimization of illumination2.3 Air Quality

Outside Air Volume

４．Use of Natural Energy4.1 Natural Lighting

Top light, Light shelf, Light Duct4.2 Natural Ventilation4.3 Earth heat Using

Earth Tube, Geo-HP4.4 Solar Heat Using

Passive and Active

５．Use of Unutilized Energy5.1 Temperature Difference

Ground Water

６．High Efficiency System6.1 Lighting

LED、Natural LightingTask & Ambient Lighting

6.2 HVACHigh Efficiency Equipment

6.3 Heat SourceHigh Efficiency System

6.4 ElectricityHigh Efficiency Trans

6.5 OthersHW Supply system

6.6 ControlBlind Control Task & Ambient Control

３．Load Reduction3.1 Shading of Sunlight

Tree, Building Shape3.2 Insulation of Envelope

Window Surface, Pair GlassDouble Skin、Roof Greening

3.3 Reduction of Inner heatWaiting Power, Clouding

７．Resource and Material7.1 Resource7.2 Materials7.3 Waste

８．Use of Renewable Energy8.1 PV8.2 Wind Power8.3 Biomass

９．Energy Management9.1 BEMS9.2 LCEM9.3 Visualization

Design Methods of Net Zero Energy Building

Fig.6 Design Methods to Actualize Net Zero Energy Building

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Definition of NZEB in SHASE of Japan

Qualitative Definition

A Net Zero-Energy Building is a building

that has a high energy saving through load reduction, natural energy use and high energy efficiency

without decreasing the environmental quality both indoor and outdoor.

With the introduction of on-site renewable energies, the energy generation will be greater than or equal to the energy consumption.

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Fig.7 Approach to NZEB（Net Zero Energy Building）

Definition of NZEB in SHASE of Japan

Net Zero Energy Building

Net Zero Energy

Reference Building

Quantitative Definition

Exported Energy

Energy use

Others

・A Site boundary identifies the physical boundary (used for zero energy accounting).・G (Energy Generation)/C(Energy Consumption) balance・ D (Dlivered Energy)/ E(Exported Energy) balance・In principle, ZEB is measured through actual annual source energy.・Energy generated on-site is used for building needs; HVAC, lighting, plug load, others (ventilation, sanitary system、EV, etc.)・In the case the appliance energy is measured, it is possible to exclude appliance energy consumption from the building needs because it does not influence the building quality and also it's out of the building designer's control.

HVAC Lighting Plug load

Ｒ：Renewable Energy

G：Energy Generation

E：Exported Energy

Building

(On-site)

electricity

fuel

heat

electricity

D：Delivered Energy

C：Energy Consumption

Site boundary

heat

electricity

Demand

Supply

Building needs

Fig.8 Energy Demand and Energy Supply Balance of NZEB

Definition of NZEB in SHASE of Japan

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Net Zero EnergyBuilding is defined as G=C or D=E

Site BoundaryBuilding

E Exported Energy

D Delivered EnergyG Energy Generation

C Energy Consumption

R Renewable Energy

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Fig.9 Quantitative Definition of NZEB（Net Zero Energy Building）

Definition of NZEB in SHASE of Japan

・The weighted demand and the supply should be in principal primary energy consumption. ・If multiplied with coefficient, CO2 emissions and energy cost can be replacable by weighted supply and demand.

・Physical definition of ZEB is represented by Ｇ≈ Ｃ or D≈ E.

00

weighted demand（kWh,MJ,kg-CO2, etc.）

net Zero Energy

weig

hte

d su

pply

（kW

h,M

J,k

g-C

O2,

etc

.）

Reference Building

net Zero Energy Building

C

G

D

E

Ｇ Ｃ

D E

ZEB Definition

G≈Cor

D≈E

Net Zero EnergyBuilding is defined as G=C or E=D

Reference Building

Net Zero Energy Building

Net Zero Energy

Weighted Demand

Wei

ghte

d Su

pply

G=C

E=D

0.5

1.00.50.250.125

0

0

基準化需要量 C*Demand

net Zero Energy Building

基準

化供

給量

G*

Reference Building

ZEB

Oriented

net Plus

Energy Building

ZEB

Ready

G*：基準化需要量＝評価対象建築物の生成エネルギー／レファレンスビルの消費エネルギーC*：基準化供給量＝評価対象建築物の消費エネルギー／レファレンスビルの消費エネルギー

nearlyZEB

レベルⅡ

0.65

nearlyZEB

レベルⅠ

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Fig.10 NZEB（Net Zero Energy Building） Evaluation Path

C*︓normalized energy consumption

Ｇ*：normalized energy generation = energy generation of target building/ energy consumption of reference buildingＣ*：normalized energy consumption = energy consumption of target building/ energy consumption of reference building

ZEB Oriented Buildings

nearlyZEB

ZEBReady

PositiveZEB

Evaluation Standard of NZEBNet Zero Energy

Reference Building

Ｇ*︓

norm

aliz

ed e

nerg

yge

nera

tion

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Definition and Evaluation of nZEB METI, Japan

Fig.11 Definition of NZEB（Net Zero Energy Building） METI, Japan

METI’s ZEB Definition is based on SHASE’s ZEB definition.Therefore these are almost same.

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Overview of Best Practices of nZEB in Japan

Fig.12 External Appearance of Best Practices of NZEB in Japan

Location of 14 Best Practices in Japan10 around of Tokyo, 2 in Kansai area , 2 in other areas

#1 #2 #3 #4

#5 #6 #7 #8

#9 #10 #11 #12 #13 #14

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Mapping of Best Practices of nZEB in Japan

Fig.13 Mapping of Best Practices of nZEB in JapanClimo-Graph of Tokyo

Location of Tokyo

4 buildings have been reached to Net Zero Energy.2 buildings are ranked in Nearly ZEB, 7 are ranked in ZEB Ready and another is ZEB Oriented.

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Guideline for Design of nZEB METI, Japan

For small office

For super marketFor hospital

For large office

Guidelines for various types of building

Design Guidelines for various types of building has been prepared.

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Pamphlet “ZEB Advanced Case Collection in Japan”

Front Cover Foreword Definition and Evaluation method of ZEB

Overview of Best Practices in Japan

14 page of Details of each Best Practice

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ZEB Demonstration Building by Taisei Corporation

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ZEB Demonstration Building by Taisei Corporation

• Location

• Building type

• Total floor area

• Number of floors

• Completion

• Certification

Basement 3 stories Penthouse 1 story1,300m2

Yokohama city （N35.42o、E139.54o）

Office

June 2014CASBEE S rank, LEED platinum, BELS☆☆☆☆☆

ZEB Demonstration Building by Taisei Corporation

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ZEB Demonstration Building by Taisei CorporationTarget of annual energy balance

Annual Energy consumption

AnnualEnergy

Generation

EnergyGeneration

TypicalBuilding

ZEBOffice

Energy Savings

25％

25

ZEB Demonstration Building by Taisei Corporation

Sensing technologyT-Zone Saver

Daylighting technologyT-Light Cube

Organic thin film PV Facade unit

Air-conditioning technologyT-Radiant Slab

Technologies

26

ZEB Demonstration Building by Taisei Corporation

Day-lighting systemWhite ceiling

Diffusion light

Overhead LightingMirror

Day-lighting System（T-Light Cube）

Day-light can be introduced to the back of room without being influenced by the sun altitude.

27

ZEB Demonstration Building by Taisei CorporationDay-lighting System（T-Light Cube）

28

ZEB Demonstration Building by Taisei Corporation

Slab-embedded piping

Fuel cell Absorption chiller

Radiant cooling from the slab

Automatic-controlled personal Floor diffuser

Personal airConditioning unit

Smart Sensor

28℃

26℃

Exhaust Heat

T-radiant slab

T-Personal air

Task & ambient AC system

29

ZEB Demonstration Building by Taisei Corporation

Roof Top Monocrystal PV

External Wall OrganicThin Film PV

PV installation

30

ZEB Demonstration Building by Taisei Corporation

Light weightUnited wall material

4.8kg/m2 7.5kg/m2

Window frame

Organic thin-film

Aluminum panel

Organicthinfilm

CrystallinePhotovoltaic

cells

PV installation

ZEB Demonstration Building by Taisei Corporation

127 kWh prim/m2･yr

Predicted energy

119 kWh prim/m2･yr

Predicted energy

137 kWh prim/m2･yr

Measured energy

129 kWh prim/m2･yr

Measured energy

Solar Radiation

Dec.Nov.Oct.

0

Apr. MayJune July Aug. Sept. Jan. Feb. Mar.

Generation

Consumption

＋

－

MeasuredPredicted

Results of annual energy balance- JUNE 2014~May 2015

31

32

ZEB Demonstration Building by Taisei Corporation

0.26(129 kWh prim/m2･yr)

0 0.125 0.5 0.65 0.75 1.0(505 kWh prim/m2･yr)

Ｇ*︓

norm

aliz

ed e

nerg

yge

nera

tion

0.5

0.375

Reduction of 74%

Generation of 27%

(134

kW

h pr

im/m

2 ･yr

)0.

27

(+8 kWh prim/m2･yr)

C*︓ normalized energy consumption

- JUNE 2014~May 2015

PositiveZEB

ZEB Evaluation

33

ZEB Demonstration Building by Taisei Corporation

LEED-NCPlatinum

BELS5-star rating

Minister of the Environment Award

“Building Energy-efficiencyLabeling System” in Japan

First Certificationin Japan

Certification and Achievements

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Future Interesting Tasks for SHASE of Japan

#1 Review of ZEB definition and evaluation method ⇒Evaluation method of biomass energy, green energy and natural energy. ⇒Definition of ZEC ( Zero Energy Community ）

#2 Framework of social value of ZEB（including Labeling）⇒Reasonableness of return on investment or cost optimization of ZEB

#3 Design method for realizing and spreading of ZEB⇒Guideline for design of ZEB

#4 Elemental technologies for realizing and spreading of ZEB⇒Especially technologies for large building

#5 Policies and incentives for realizing and spreading of ZEB#6 Tools for realizing and spreading of ZEB#7 Roadmap for realizing of ZEB

Thanks for your attention