Transcript Closing the Gap

Carbon Emissions and the Need
for Improved Energy Efficiency
Overview
• The carbon credibility gap
• How can it be bridged: renewables vs
demand reduction?
• Where can we reduce our energy
consumption
• Technologies and mechanisms for
improved energy efficiency
Targets
• In response to the increasing body of
evidence pointing to global warming the
government has signed up to targets for GHG
emissions:
– Kyoto protocol (ratified 2005) emissions 12.5%
below 1990 levels during 2008-12 [DEFRA]
• Also has aspirations for
– 18% renewables by 2010, 40% by 2020 [S. Exec]
– 60% cut by 2050 [SEPN]
Credibility Gap?
• Are we on target to achieve the 60%
target?
• Equates to a reduction of approx. 90
million tonnes per annum in carbon
emissions
• How do we achieve this?
The Carbon Credibility Gap
UK C Emissions 1970-2050
210
190
Emissions MtC
170
150
the emissions
gap
130
110
90
70
50
1970
1980
1990
2000
2010
Year
projected emissions from DEFRA
2020
2030
2040
2050
Emissions
Target
Projected
Bridging the Gap
• Closing the emissions gap requires action in
both energy supply and demand
– increased use of energy efficient and renewable
sources of energy
– and improved energy efficiency resulting in
reduced energy consumption
Energy & Electricity Demand
• 50% of anticipated C savings from energy efficiency [SEPN]
• Target of 10 MtC per annum by 2010 from energy efficiency (Scotland
1MtC) and 10MtC from the domestic sector alone by 2020 [SEPN]
• A range of measures implemented to attain this objective: CCL, EEC,
updated building regs, etc.
• Electrical consumption is increasing at 2% per annum & energy
consumption increasing at 1% per annum [DTI]
• Required increase in UK renewables output to meet 15% target: 50
TWh or 425 new 40MW wind farms
• Potential increase in UK electrical demand with current trends: 90 TWh
Energy & Electricity Demand
Demand and Renewables Output
600000
500000
GWh
400000
electricity demand
300000
renewables output
200000
9.34E+04
100000
6.37E+04
3.86E+04
1.14E+04
0
2002
2004
2006
2008
2010
2012
Year
2014
2016
2018
2020
Built Environment
Built Environment
• Energy efficiency improvements in the built
environment will have a major impact on emissions
• accounts for >50% of delivered energy consumption
• large scope for energy savings due to poor levels of
energy efficiency (particularly domestic sector)
• built environment can also impact upon transport 60% of vehicle journeys related to domestic use [S.
Exec]
Sector Targets
• Government GHG emissions targets in energy
efficiency are defined in MtC
• The magnitude of required energy savings kWh will
depend upon:
– supply mix
– performance of other sectors (particularly transport)
• If transport fails to deliver (e.g. hydrogen fuel) built
environment may have to take up the slack
• What scale of energy savings are required?
• Scenario based modelling approach is useful ...
Example: Domestic Sector
• Using a simple housing stock model the C emissions
for the domestic sector are calculated for the current
electricity supply mix and post 2020 mix (0% nuclear,
40% RE, 60% fossil fuel) for the following scenarios:
– continuing current trends (increasing heat and electricity
demand)
– 30% reduction in heat demand
– 30% reduction in heat and electricity demand
• The desired reduction for carbon from the domestic
sector is also shown
Example: Domestic Sector
Carbon Emissions MtC
4.5
domestic emissions
only
4
Million Tonnes Carbon
3.5
emissions including
electrical related
emissions
3
2.5
supply:
0% nuclear
40% RE
60% fossil
2
1.5
1
target
demand:
static
0.5
0
current
2020
Example: Domestic Sector
Carbon Emissions MtC
4.5
domestic emissions
only
4
Million Tonnes Carbon
3.5
emissions including
electrical related
emissions
3
2.5
supply:
0% nuclear
40% RE
60% fossil
2
1.5
1
target
demand:
heat demand
reduced by 30%
0.5
0
current
2020
Example: Domestic Sector
Carbon Emissions MtC
4.5
domestic emissions
only
4
emissions including
electrical related
emissions
Million Tonnes Carbon
3.5
3
2.5
supply:
0% nuclear
40% RE
60% fossil
2
1.5
1
target
0.5
0
current
2020
demand:
heat and electrical
demand reduced by
30%
Example: Domestic Sector
• Only through reducing domestic heat and power
demand do we achieve any carbon savings
• Even with 40% renewables but with increasing
demand carbon emissions are still greater in 2020!
Achieving Energy Savings
• How can we bring about the necessary
energy savings?
– drivers: legislation, planning and cost
– mechanisms: better fabric, controls,
renewables, design, etc.
Legislation, Planning and Cost
• Planning
– building location
– orientation & solar access
• Legislation
–
–
–
–
–
–
maintenance
insulation levels
component specs
passive solar
integrated renewables
energy monitoring
• Energy costs
Improved Building Fabric
• technologies:
– advanced glazings and frames,
– improved insulation
• primary benefits:
–
–
–
–
increased internal temperatures
reduced energy consumption
reduced condensation and dampness
reduced fabric damage from moisture
• secondary benefits:
– improved occupant health
• potential:
40-80% savings in heating energy consumption [Oliver, 2001]
•
Improved Systems and
Controls
technologies:
–
–
–
–
–
–
•
daylight responsive controls
low energy lighting
occupancy responsive control
condensing boilers
controls and services zoning
variable speed drives
benefits
– reduced heat and power demand
– improved internal conditions
•
potential:
– 50-90% savings in power consumption
with efficient lighting and daylighting
control [Knight, 1999]
•
current status
– being promoted through CCL
Combined Heat and Power
• Technologies
– gas/diesel fuelled ICE
– gas turbine
– micro turbines & micro CHP (domestic)
• Potential
– reduces emissions by 10-50% depending upon
alternative heat and power sources
• Current situation
– 10GW target by 2010 [DTI]
– currently hampered by NETA, SRO and poor
gas/electricity price differential
– reduction in CHP installed capacity since 2001
[CHPA]
Integrated Renewables
• Technologies
– photovoltaics
– solar thermal
– micro wind turbines
• Potential
– solar thermal can significantly
reduce domestic hot water heating
requirements
– PV and micro-turbines energy
potential ~ 90-120kWh/m2
• Current situation
– 42,000 solar thermal systems in UK
[STA]
– 11 MWp of installed PV [IEA]
Integrated Renewables
PV Supply vs Energy Demand
Annual Energy kWh/m2
400
350
Supply from PV (25% floor
area)
Demand (typical high tech
office)
Demand 50% reduction
300
250
200
150
Demand 75% reduction
100
50
0
demand data: ECGO 19
Heat Pumps
• Technology:
– ground source heat pumps
– air source heat pumps
• Potential:
– newer air source heat pumps
potential for 50% reduction in CO2
emissions [Ustrath]
• Current situation
– very few systems installed in the UK
– hampered by gas/electricity cost
differential
Emerging Technologies
• Technologies:
–
–
–
–
–
fuel cells
micro-CHP
urban wind power
advanced glazing
etc.
• Potential
– unknown
• Current Situation
– embryonic stage
Technology Costs
Capital Costs of Various Heat and Power Production Technologies
4000.00
3500.00
3000.00
£/kW output
2500.00
2000.00
1500.00
1000.00
500.00
0.00
PV
Fuel Cells Small Wind
Turbine
GSHP
ASHP
Diesel
Generator
CHP
CCGT
Boiler
Conclusions
• Reducing energy demand is essential if GHG
reduction targets are to be met
• Renewables alone will not be sufficient
• Magnitude of reduction in energy
requirements will depend upon
– supply mix
– conversion efficiencies
– reductions in other sectors
Conclusions
• The built environment offers rich potential for energy
savings
• Emissions reductions targets can me met with
relatively modest reductions in energy consumption
• Significant savings can be made with simple
measures
– improved building design
– maintenance
– better use of existing technologies
Conclusions
• A range of energy supply technologies are also
becoming available as design options but most are
hampered by high cost
• Hopefully UK energy policy is moving towards a
balance of demand and supply measures
• Only with this balance do we have the possibility of
drastically reducing emissions
• … and only with demand side improvements we can
also begin to address our problems of fuel poverty
and ill health