Carbon Emissions and the Need for Improved Energy Efficiency

Carbon Emissions and the Need for Improved Energy Efficiency

OverviewOverview

• 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

TargetsTargets

• 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?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?

UK C Emissions 1970-2050

50

70

90

110

130

150

170

190

210

1970 1980 1990 2000 2010 2020 2030 2040 2050

Year

Em

issi

on

s M

tC

Emissions

Target

Projected

The Carbon Credibility GapThe Carbon Credibility Gap

the emissions the emissions gapgap

projected emissions from DEFRA

Bridging the GapBridging 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 DemandEnergy & 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 DemandEnergy & Electricity DemandDemand and Renewables Output

1.14E+04

3.86E+04

6.37E+04

9.34E+04

0

100000

200000

300000

400000

500000

600000

2002 2004 2006 2008 2010 2012 2014 2016 2018 2020

Year

GW

h electricity demand

renewables output

Built EnvironmentBuilt Environment

Built EnvironmentBuilt 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 TargetsSector 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 SectorExample: 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 SectorExample: Domestic SectorCarbon Emissions MtC

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Mil

lio

n T

on

nes

Car

bo

n

domestic emissionsonly

emissions includingelectrical relatedemissions

current 2020

supply: 0% nuclear40% RE60% fossil

demand:static

target

Carbon Emissions MtC

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Mil

lio

n T

on

nes

Car

bo

n

domestic emissionsonly

emissions includingelectrical relatedemissions

current 2020

supply: 0% nuclear40% RE60% fossil

demand:heat demand reduced by 30%

Example: Domestic SectorExample: Domestic Sector

target

Carbon Emissions MtC

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Mil

lio

n T

on

nes

Car

bo

n

domestic emissionsonly

emissions includingelectrical relatedemissions

current 2020

supply: 0% nuclear40% RE60% fossil

demand:heat and electrical demand reduced by 30%

Example: Domestic SectorExample: Domestic Sector

target

Example: Domestic SectorExample: 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 SavingsAchieving 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 CostLegislation, 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 FabricImproved 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

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 PowerCombined 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 RenewablesIntegrated 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 RenewablesIntegrated Renewables

PV Supply vs Energy Demand

0

50

100

150

200

250

300

350

400

An

nu

al

En

erg

y k

Wh

/m2

Supply from PV (25% floorarea)

Demand (typical high techoffice)

Demand 50% reduction

Demand 75% reduction

demand data: ECGO 19

Heat PumpsHeat 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 TechnologiesEmerging Technologies

• Technologies: – fuel cells– micro-CHP– urban wind power– advanced glazing– etc.

• Potential – unknown

• Current Situation– embryonic stage

Technology CostsTechnology CostsCapital Costs of Various Heat and Power Production Technologies

0.00

500.00

1000.00

1500.00

2000.00

2500.00

3000.00

3500.00

4000.00

PV Fuel Cells Small WindTurbine

GSHP ASHP DieselGenerator

CHP CCGT Boiler

£/k

W o

utp

ut

Capital Costs of Various Heat and Power Production Technologies

0.00

500.00

1000.00

1500.00

2000.00

2500.00

3000.00

3500.00

4000.00

PV Fuel Cells Small WindTurbine

GSHP ASHP DieselGenerator

CHP CCGT Boiler

£/k

W o

utp

ut

ConclusionsConclusions

• 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

ConclusionsConclusions

• 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

ConclusionsConclusions

• 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