Green Buildings; Green Cities Why so long? Phil Jones
Green Buildings; Green Cities
Why so long?
Phil Jones
20km (m90%)
Global warming < 1.5oC by 2050
based on pre industrial times
Built environment a major target for reducing CO2 emissions
• A major source of CO2 emissions
• Climate change impact, especially vulnerable groups
Low energy design:
• Energy efficient design
• Thermal insulation
• Air tightness
• Efficient HVAC
Passive design:
+•Solar
• Daylight
• Natural ventilation
• Thermal mass
Sustainable design:
+•Materials
• Renewable energy
• Community
Zero Carbon design:
+• Reduce energy demand
• Renewable energy supply
• Appliance energy
• Low embodied energy
1970’s 2018
Energy Positive design
+• Nearly zero energy demand
• Renewable energy supply
• Energy storage
LOW ENERGY TO ZERO CARBON
Building City Scale
New Build Retrofit
320ppm—409ppm
0.8oC
2030 targets:•Reducing greenhouse gas emissions by 40% (from 1990 levels)• Increasing the share of renewable energy to at least 27%•Continued improvements in energy efficiency (at least 27%)
2020 Targets
• 20% cut in greenhouse gas emissions (from 1990 levels)
• 20% of EU energy from renewables
• 20% improvement in energy efficiency
2040 targets:•Reducing greenhouse gas emissions by 60%
2050 targets:•Reducing greenhouse gas emissions by 80%
POLICY
EUROPE
• The Energy Performance of Building Directive (EPBD)
• new public buildings after December 31, 2018
• all new buildings after December 31, 2020.
• A NZEB is a building that "has a very high energy
performance with the nearly zero or very low amount of
energy required covered to a very significant extent by
energy from renewable sources, including energy from
renewable sources produced on-site or nearby".
• Implemented through Building Regulations.
(D'Agostino et al., Synthesis Report on the National Plans for NZEBs; EUR 27804
EN; doi 10.2790/659611 )|
Nearly Zero Energy Buildings (NZEBs)
POLICY
INCREMENTAL
ELEMENTAL
HOLISTIC APPROACH
0
50
100
150
200
250
300
350
400
450
500
1965
1976
1982
1990
1995
2002
2006
zero carbo
n
An
nu
al
he
ati
ng
lo
ad
kW
h/m
2
0
2
4
6
8
10
12
14
16
18
De
sig
n h
ea
t lo
ss
kW
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
1965
1976
1982
1990
1995
2002
2006
U-V
AL
UE
S wall roof floor
0
50
100
150
200
250
300
350
400
450
500
1965
1976
1982
1990
1995
2002
2006
zero carbo
n
An
nu
al
he
ati
ng
lo
ad
kW
h/m
2
0
2
4
6
8
10
12
14
16
18
De
sig
n h
ea
t lo
ss
kW
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
1965
1976
1982
1990
1995
2002
2006
U-V
AL
UE
S wall roof floor
Thermal Insulation
Energy
Storage
TECHNOLOGY AND DESIGN TOOLS
We have the technologies,
and the modelling capabilities,
to design and construct buildings and cities by
simulating energy and environmental performance.
Transpired Solar Air Collectors (TSCs)
Energy Generating Building Envelopes
Solar PV and Solar thermal
Renewable Energy
Cardiff University researchers completed energy-harvesting façade and roof retrofit
in Tibet as part of its HABITAT Global Challenge Research project.
0.0
100.0
200.0
300.0
400.0
500.0
600.0
700.0
800.0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Monthly energy supply, PV power storage and exportation
Direct from PV From Battery Heating storage by PV power Surplus power to grid From grid
Energy: kWh
AIR
CO
LL
EC
TO
R
SYSTEMS APPROACHREDUCE DEMAND
RENEWABLE SUPPLY
ENERGY STORAGE
Structurally insulated Panel Construction
After retrofit
Before retrofit
1 2 3 4 5
1 2 3 4 5
RETROFIT
EMPA near-zero carbon office, Zurich
TECHNOLOGIES + TOOLS
WINTER
SUMMER
COMFORT IN GREEN BUILDING ?
Surface heating and cooling
Solar gains
Chilled beams/panelsVentilation
Internal gains
Façade design
H2020 EeB-07-2017 EU contribution €6m
2017-2021
Plug-n-Harvest
OPTIONS:
Thermal insulation; PV generation; battery storage;
solar thermal air heating; mechanical ventilation;
Renewable generationPV and Thermal
Technical Zonestorage; ventilation
Thermal insulation
URBAN SCALE
Sustainable High Density Cities Lab
CityComfort+
Air Ventilation Analysis:
Daylighting Analysis:
Building Energy:
Thermal comfort:
URBAN SCALE TOOLS
Option1
Option2 Option3
Existing condition
0.00
20.00
40.00
60.00
80.00
100.00
120.00
140.00
160.00
180.00
200.00
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59
Energy supply per building
Heating Cooling Lighting Small power Fan power
kwh/m2/annual
Building ID
0.00
5.00
10.00
15.00
20.00
25.00
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Energy supply per area
Heating Cooling Lighting Small power Fan power
kwh/m2/month
Large Scale low carbon Urban Developments
50% Building Integrated
Renewables
Integrated Model:
Urban Microclimate (UMM) + Energy (HTB2)
UMM HTB2 Surface temperatures
Air exhaust
Air temperatures Wind flow
3-D Geometry / Weather data / Building properties Plants cooling Traffic heat gains
Improve external comfort
Reduce building energy demand
URBAN TEMPERATURES
Model Testing on a Scale Concrete City (Guangzhou)
A zonal model for assessing street canyon air temperature of high-density cities, Weihui Liang, Jianxiang Huang, Phil Jones, Qun
Wang, Jian Hang, Building and Environment Vol 132, 15 March 2018, Pages 160-169
CITY AS A BUILDING
Heat gains
Ventilation
Cooling
Daylight
Noise
Renewable
energy
After retrofit
Before retrofit
1 2 3 4 5
1 2 3 4 5
Energy
Positive
Zero
Carbon
Near-Zero
Carbon
Low
Carbon
NE
W B
UIL
DR
ET
RO
FIT
UR
BA
N
SC
AL
E
BUILT ENVIRONMENT
Buildings
Communities
Grids
Renewable Energy
+
Energy Storage
Future Energy Systemsand
The Built Environment
BARRIERS AND BENEFITS
WHY SO LONG?
• Lack awareness
• Industry resists change
• Government does not push
• Procurement lock-in
• Uncertainties: costs / performance
• Who owns it - architect, engineer,
building physicist?
BENEFITS (MULTIPLE)
Building / Community
• Energy cost savings
• Comfort, health and well-being
• Productivity increase
• Increase asset and rental value
• Less pollution
National / Global
• Carbon emissions reduction.
• Reduced use of resources.
• Security of energy supply.
• Reduced environmental damage
• Public health savings
Chinese Vice Premier Liu Yandong visits the SOLCER House
Thank You