Network theory integrated life cycle assessment for an electric power system

Heetae Kim, Petter HolmeDepartment of Energy Science, SKKU, South Korea

Ecobalance2014, 27-30 October, Tsukuba, Japan

Motivation

10km

Santiago

Curico

50km

Cost-benefit mismatch

Electric power system

Transmission

From resources to energy services

Consumption Generation

Power plantsUsers Infrastructures

Electric power system

Consumption Generation

Infrastructures Power plantsUsers

Relationship between generation and consumption

Electric power system

Consumption Generation

CO2

Infrastructures Power plantsUsers

Relationship between generation and consumption

Electric power system

Power plantsUsers

TransmissionConsumption

Infrastructures

Relationship between transmission and consumption

Electric power system

Power plantsUsers

TransmissionConsumption

Infrastructures

Relationship between transmission and consumption

Electric power system

Power plantsUsers

TransmissionConsumption

Infrastructures

Relationship between transmission and consumption

Transmission distance

? km

Inventory to impacts: ideal

Total emissions

Resource combustion

Conversion factorResource

consumptionElectricity

consumption

Transmission facilities Conversion factor Facility use

km

Transmission distance

CO2

CO2

×

×

Functional indexEnvironmental impacts

Conversion factor ×=

measured by

measured by

conversion process corresponding to transmission and generation

Transmission facilities

Resource combustion

=

=

Inventory to impacts: limitation

Total emissions

Resource combustion

Conversion factorResource

consumptionElectricity

consumption

Transmission facilities Conversion factor Facility use

km

Transmission distance

CO2

CO2

×

×

Functional indexEnvironmental impacts

Conversion factor ×=

Transmission load is difficult to consider separately

Transmission facilities

Resource combustion

=

=

measured by

measured by

Inventory to impacts: limitation

Total emissions

Resource combustion

Conversion factorResource

consumptionElectricity

consumption

Transmission facilities Conversion factor Facility use

km

Transmission distance

CO2

CO2

×

×

Functional indexEnvironmental impacts

Conversion factor ×=

Transmission load is difficult to consider separately

Transmission facilities

Resource combustion

=

=

measured by

measured by

Inventory to impacts: limitation

Total emissions

Resource combustion

Conversion factorResource

consumptionElectricity

consumption

Transmission facilities Conversion factor Facility use

km

Transmission distance

CO2

CO2

×

×

Functional indexEnvironmental impacts

Conversion factor ×=

Transmission load is difficult to consider separately

Transmission facilities

Resource combustion

=

=

measured by

measured by

Inventory to impacts: limitation

Total emissions

Resource combustion

Conversion factorResource

consumptionElectricity

consumption

Transmission facilities Conversion factor Facility use

km

Transmission distance

CO2

CO2

×

×

Functional indexEnvironmental impacts

Conversion factor ×=

Transmission load is difficult to consider separately

Transmission facilities

Resource combustion

=

=

measured by

measured by

Inventory to impacts: current

Total emissions

Resource combustion

Conversion factorResource

consumptionElectricity

consumption

Transmission facilities

Conversion factor Facility use

km

Transmission distance

CO2

CO2

×

×

Functional indexEnvironmental impacts

Conversion factor ×=

Transmission facilities

Resource combustion

Transmission facilities

Resource combustion

=

=

measured by

measured by

The merged conversion factor and functional index are used

However, the transmission load will not be negligible because …

Environmental impacts from transmission facility is neglected (< 5 % of total)

CO2 ×=Electricity

consumptionMerged

conversion factor

Environmental impacts timeline

Construction Operation & maintenance

Transmission facilities

Resource combustion

•Increasing cost of transmission facilities - Super conductive material, smart grid

Environmental impacts timeline

Construction Operation & maintenance

Transmission facilities

Resource combustion

•Increasing cost of transmission facilities - Super conductive material, smart grid

•Decreasing fossil fuels- Solar power, wind power, etc.

Environmental impacts timeline

Construction Operation & maintenance

Transmission facilities

Resource combustion

•Increasing cost of transmission facilities - Super conductive material, smart grid

•Decreasing fossil fuels- Solar power, wind power, etc.

•Sensitive stakeholder economy - International electric power trade and transmission

Environmental impacts timeline

Construction Operation & maintenance

Transmission facilities

Resource combustion

International transmission projects

International transmission projects

NorNed

International transmission projects

International transmission projects

Asia Super Grid

International transmission projects

International transmission projects

DeserTec

International transmission projects

Research purpose

✴ Allocate environmental impacts of electric power to regions according to both electricity consumption and transmission load

✴ Integrate network theory into LCA

Method outline

Method outline

Total GHG emissions1

Method outline

Energy distance2Total GHG emissions1

Method outline

Energy distance2 GHG allocation3Total GHG emissions1

Inventory analysis

SIC center of Economic Load Dispatch (CDEC-SIC) ✓the main national electricity company ✓serves 92% of country’s population ✓10 regions out of 15 ✓42 provinces out of 57

Data collection ✓2007 to 2012

System boundary

Inventory analysis

SIC center of Economic Load Dispatch (CDEC-SIC) ✓the main national electricity company ✓serves 92% of country’s population ✓10 regions out of 15 ✓42 provinces out of 57

Data collection ✓2007 to 2012

System boundary

Developing Chilean conversion factor

g CO2/ kWh GWh

0.006 325

0.266 13,450

0.157 7,946

0.285 14,385

0.027 1,358

0.020 1,013

0.239 12,072

= 23.02 Mt CO2-eq

Greenhouse gas (GHG) emissions of Chilean electric power system

Network generation

<Transmission system dada>

CDEC-SIC Annual report (2014)

Network generation

<Transmission system dada>

Node (Poser plant)

Link (Transmission line)

Agua santa

PlacillaNode

(Substation)

CDEC-SIC Annual report (2014)

Network generation

Node (Poser plant)

Link (Transmission line)

Agua santa

PlacillaNode

(Substation)

CDEC-SIC Annual report (2014)

466 nodes

↳129 power plants 291 substations 46 towers

543 edges

Network generation

Node (Poser plant)

Link (Transmission line)

Agua santa

PlacillaNode

(Substation)

CDEC-SIC Annual report (2014)

466 nodes

↳129 power plants 291 substations 46 towers

543 edges

Network generation466 nodes

↳129 power plants 291 substations 46 towers

543 edges

Transmission algorithm

Amount of electricity consumption × Transmission distance

i : a substation node j : a power plant node aij: electricity supply from j to i dij : transmission distance from j to i nhd(i) : neighbor nodes of i Edi : energy distance of i

i

j Power plant

Substation

Transmission

distance dij

2

A

B

1

Greedy algorithm ↳the nearest substation has the top priority and the others are supplied subsequently

Poss

ible

p

air

Tra

nsm

issio

n

dist

an

ce

Optimal

Electricity

supply aij

Edi =f (aij ,dij )

j∈nhd (i )

k

∑

f (aij ,dij )j∈nhd (i )

k

∑i=1

n

∑

Energy distance

Result

Transmission distance

Electricity consumption

1200 MWh 4000 km 10 %

Comprehensive system load

0 0 0

Result

Transmission distance

Electricity consumption

1200 MWh 4000 km 10 %

Comprehensive system load

0 0 0

Result

Transmission distance

Electricity consumption

1200 MWh 4000 km 10 %

Comprehensive system load

0 0 0

Result

Transmission distance

Electricity consumption

1200 MWh 4000 km 10 %

Comprehensive system load

0 0 0

Result

Result

by energy distanceby consumption

676

66000

kt CO2

Regional greenhouse gas emissions allocated

30000

Result

by energy distanceby consumption

676

66000

kt CO2

Regional greenhouse gas emissions allocated

30000

Conclusion

Network analysis on electric power grid

↳ Useful complement to LCA analysis

Transmission load adjusted allocation ↳ Consider both of electricity consumption and transmission distance

Re-allocate environmental impacts to users ↳ Life cycle assessment on GHG emissions ↳ Energy distance analysis ↳ Make the fair allocation possible

Acknowledgement

Thank you for your attention! Any question?

Prof. Petter Holme Fariba Karimi Heetae Kim Eun Lee Minjin Lee Prof. Sang Hoon Lee

National Research Foundation in Korea

kimheetae@gmail.com