Transcript Slide 1

Resilience in complex socio-technical systems
L. Andrew Bollinger
PhD student
Section Energy & Industry
Faculty of Technology, Policy & Management
TU Delft
19 March 2012
SPM 4530
Contents
1. Background – my research
2. Resilience and related concepts
3. Resilience and complex adaptive systems
4. Infrastructure resilience
5. Demonstration models
Background
Adaptation of electricity infrastructures to climate change
Research question:
•
How can we develop effective strategies to support the resilience of the
Dutch electricity infrastructure to climate change?
Approach:
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Socio-technical systems
Complex adaptive systems
Hurricane Katrina (2005)
Pakistan floods (2010)
European heat wave (2006)
Resilience and related concepts
De Haan et al. (2011):
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A flexible infrastructure constellation can be employed differently to keep on
meeting a societal need under changed circumstances
• An adaptive infrastructure constellation can be altered to keep on meeting a
societal need under changed circumstances
• A resilient infrastructure constellation can resume meeting a societal need
under changed circumstances
• A robust infrastructure constellation can keep on meeting a societal need under
changed circumstances
Source: De Haan, J, et al. Framing flexibility. Futures. 43:9, 923–933.
Robustness vs. resilience
Robustness – some definitions:
• The ability to sustain a disruption (Quirk and Fernandez)
• The capacity (of a complex system) to maintain some desired system
characteristics despite fluctuations in the behavior of its components or its
environment (Carlson).
Image source: Husdal, 2009
Robustness vs. resilience
What are some characteristics of a robust (electricity) infrastructure?
Robustness vs. resilience
What are some characteristics of a resilient (electricity) infrastructure?
Resilience
Resilience – some definitions:
1. The ability to bounce back from large scale disruptions (Sheffi).
2. The ability of a system to gracefully degrade and to quickly self-recover to a
normal state (Mili).
3. The ability of a system to recover from adversity, either back to its original state
or an adjusted state based on new requirements (McCarthy).
Image source: Husdal, 2009
Complex adaptive systems
Systems in which macro-level patterns are viewed as emerging from the
actions and interactions of numerous “agents”
• Nonlinearity
• Emergence
• Adaptiveness
• Chaos
• Path dependency
• Multiple attractors
Attractors in complex adaptive systems
Attractor: A set of states to which a complex system is attracted
Point attractor
Periodic attractor
(limit cycle)
Multiple attractors
Resilience in social-ecological systems
Stability landscape
Basin of attraction
Resilience:
“The capacity of a system to absorb disturbance and reorganize while
undergoing change so as to still retain essentially the same function, structure,
identity, and feedbacks—in other words, stay in the same basin of attraction.“
(Walker, et al. 2004)
Resilience in social-ecological systems
Basins of attraction in
shallow lake ecosystems
Attractor 1
Attractor 2
Source: Scheffer, 1999
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What attractors exist in an electricity infrastructure?
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?
?
Attractors in electricity infrastructures
Rolling blackout
Demand-side
regulation?
Fluctuating load demand satisfaction
Fluctuating voltage & power flows
within a particular grid area
(periodic attractor?)
“Normal” operation
100% load demand satisfaction
50 Hz network frequency
220v demand-side voltage
Uncontrolled blackout
0% load demand satisfaction
Brownout
Stable lower voltage
Reduced functionality of loads
Attractors in electricity infrastructures
1. Attractors as “modes of operation” in the power system
2. Attractors as stable combinations of technologies and institutions in
the power system
Current attractor
Fossil fuel combustion technologies
Vertically operated grid
Heavily redundant grid structure (n-1)
Expectation of constant load demand
satisfaction
Alternative attractor
Small-scale renewables
Distributed generation
Horizontally operated grid
Less reliance on HV grid
Attractors in electricity infrastructures
Interaction between timescales
Evolutionary
timescale
Operational
timescale
Adaptive cycles and panarchy
Panarchy
Adaptive cycle
Source: Holling, 1986
Attractors vs. regimes in transition theory
Smith & Stirling, 2010:
Is resilience always desirable in socio-technical systems?
Source: Brugge and Rotmans, 2007
Source: Geels and Kemp, 2000
Resilience in socio-technical systems
Resilience in social-ecological systems:
• The capacity of a system to remain within a given basin of attraction.
A key difference between ecological and technical systems:
• In technical systems, shifts between attractors, and often the existence
of these attractors at all, are managed (albeit incompletely) by the
system’s social components.
Resilience in socio-technical / infrastructure systems:
• The capacity to manage shifts between attractors
(for the purpose of preserving an infrastructure service).
Resilience in socio-technical systems – an example
“Afgelopen winter werd door het extreme weer het hele
treinverkeer een paar keer stilgelegd. Om dit te voorkomen
hebben de NS en ProRail geïnvesteerd in technische aanpassingen
van treinen en het plaatsen van wisselwarmers .... Ook is er
een speciale winterdienstregeling ontworpen, die in kan worden
gezet bij extreem winterweer.” – NOS, Oct. 2010
Resilience in socio-technical systems
Demonstration model 1
Resilience in socio-technical systems
Demonstration model 2
Resilience in socio-technical systems
Demonstration model 2
Operational timescale
Evolutionary timescale
A robust electricity infrastructure?
Average interruption time per customer per year (2007)
Minutes
Source: Renewables International