Storm Risk Assessment of Interdependent Infrastructure Networks

Lead Research Organisation: Newcastle University
Department Name: Sch of Engineering

Abstract

Electricity infrastructure provides a vital services to consumers. Across the UK there are thousands of miles of overhead lines and other assets that are vulnerable to a number of environmental risks. Wind risks have caused more disruptions to power supplies in the UK than any other environmental risks. Despite their importance, the future risks associated with windstorm disruption are currently highly uncertain as the coarse spatial resolution of climate models makes them unable to properly represent wind storm processes.

STRAIN will address two challenges for infrastructure operators and stakeholders who are urgently seeking to understand and mitigate wind related risks in their pursuit to deliver more reliable services:

(i) Build upon state-of-the-art modelling and analysis capabilities to assess the vulnerability of electricity networks and their engineering assets to high winds. This will consider the impact of different extreme wind events, over different parts of the electricity network, the households and businesses connected, and also apply a model representing infrastructure inter-connections to understand the potential impact on other infrastructures that require electricity such as road, rail and water systems.

(ii) Climate models provide very uncertain wind projections, yet infrastructure operators require an understanding of future climate change to develop long term asset management strategies. To provide the necessary information we shall work with the Met Office and benefit from new high resolution simulations of future wind climate using a 1.5km climate model. These simulations have proven capable of representing convective storm processes, that drive many storms across the UK, and have already proven that they better capture extreme rainfall events.

These methods will be applied to a case study of an electricity distribution network. These are more vulnerable to windstorms than the high voltage national transmission network.

STRAIN will therefore, by synthesising and translating cutting-edge research, provide electricity distribution network operators with a significantly improved understanding of wind risks both now and in the longer term. This will improve the reliability of electricity supply to UK consumers including other infrastructure providers reliant on electricity distribution networks, and reduce costs by enabling more effective allocation of investments in adaptation and asset management. Furthermore, it will help other infrastructure service providers better understand the impacts of electricity disruption on their own systems, and plan accordingly. The improved understanding of future extreme wind storms will provide benefits across an even wider group of infrastructure and built environment stakeholders.

Planned Impact

A reliable supply of electricity is fundamental to the UK and global economy, and to the health and wellbeing of citizens. In the UK, windstorms pose the most significant threat to electricity distribution, yet long term changes in wind are one of the most uncertain climate model outputs posing challenges for long term planning and asset management.

Assessment of these risks is complicated by a complex infrastructure: half a million miles or so of cable across the UK, and many other assets such as substations and transformers, that deliver this service. For example - case study partners, Northern Powergrid, serve 3.8m customers, manage an enormous infrastructure asset base, including 91,000 miles overhead lines and cables and 31,000 substations, that sprawls across an area of 25,000km2.

Future investment in the electricity sector will be significant - the 2014 National Infrastructure Plan identified £38bn investment in electricity transmission and distribution by 2020-21. Electricity is fundamental to the continued operation of other infrastructures (including transport, water and ICT), and globally some $40trillion (over 3% gross world product) is forecast by the World Bank to be invested in infrastructure over the next twenty years.

The most significant initial impact on the electricity sector will be in the Norther Powergrid (NPG) region as they are our case study partners. Their 3.8m customers will therefore be the first to benefit from their electricity provider exploiting the latest science and understanding of wind related risks to enhance the resilience of their system. However, we will work with NPG and our other partners that include infrastructure providers and engineering consultancies, to disseminate and promote wider uptake and impact of the STRAIN modelling capabilities to reduce environmental risks to infrastructure systems and to allow UK consultancies to extend their reach.

The better understanding of wind risks to electricity network, and the utility of this analysis to enhance energy resilience and reduce asset management costs through better-targeted interventions, that STRAIN will provide will therefore have huge economic and social benefits.

Publications

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Description Electricity infrastructure provides a vital services to consumers. Across the UK there are thousands of miles of overhead lines and other assets that are vulnerable to a number of environmental risks. Of these, wind has caused more disruptions in the UK, moreover the future risks associated with windstorm disruption are currently highly uncertain as climate models are unable to represent these processes.

STRAIN benefitted from new high resolution simulations of future wind climate using the UK Met Office's 1.5km climate model that can represent convective storm processes that drive many storms across the UK. Integration of this high resolution climate modelling data with information on the structural properties of electricity network assets, and an infrastructure network model has enabled significant improvements in the analysis of current and future wind risks.

The two methods were adapted in order to be integrated together, and subsequently applied to a case study. Wind storms can cover a large geographical area, have peaks of intensity at multiple locations, and wind intensities that vary in time. To assess the impacts of variations in time and space of wind storms to the resilience of electricity systems, a time series analysis approach is used to assess current and future wind risks. Timeseries of spatial patterns of wind, on the 1.5km grid, are mapped over the electricity network to provide a wind loading at the transmission towers. Using the fragility function the wind loading is then converted into a failure probability. A line fails if any of its supporting towers collapse and the network link becomes inactive, disconnecting any generation capacity, or removing any associated demand from the system. Performance metrics such as loss of (generation) load, length of line disrupted, customer energy not supplied, were calculated under current and future wind conditions.

In partnership with the electricity distribution network operator Northern Powergrid we applied this integrated assessment model to part of their region around Humberside which was one of the areas identified to be of particular interest. Data was exported from their in-house GIS database. The domain included over 1000km of power lines and 7000 pylons, and served more than 260,000 customers but did not include distribution lines of lower than 33kV as the length of cabling would be at least an order of magnitude greater, besides many of the lower voltage lines are the 'last mile' into houses and are buried underground. Northern Powergrid provided extensive support and access to technical and operations staff to help access, interpret and use their large dataset.
Exploitation Route We have developed network analysis tools that we intend to make widely available. The work provides a platform and framework for other infrastructure risk and resilience studies - either to develop new research directions, or to apply it in industrial decision making in different sectors.
Sectors Energy,Environment

 
Description Transforming UK public services: Improving the resilience of Northern Powergrid's (NPG) infrastructure is huge: they serve 3.8m customers in an area of 25,000km2 that contains an enormous infrastructure asset base (including 91,000 miles overhead lines and cables and 31,000 substations). They have been notably impacted by storms in April 2012 and winters of 2013/14 and 2015/16. Understanding the risks associated with wind, both now and in the longer term, are of enormous importance to long term strategic investment planning: the 2015-2023 business plan involves £4bn investment. A key finding is that the improved climate dataset shows no statistically significant increase in wind risks in the case study site (although analysis of the wind field for the entire UK suggests this will not be the same across the country). However, windstorms are currently a sufficiently frequent and serious event that the key output of this work has been a risk-based approach to identify and prioritise assets for upgrade, replacement and additional redundancy. UK Policy Leadership: Wind risks to infrastructure were identified by the 2017 Climate Change Risk Assessment as one of the biggest uncertainties to UK infrastructure. Although this work was completed too early to feed into the 2017 assessment, it goes some way to reducing these uncertainties, and quantifying future risks, for the 2022 assessment. UK Competitive advantage and Replicability: We quickly recognised that each electricity operator has slightly different platforms, but they do collect a lot of similar data. The consistent datasets (e.g. line location, generation capacity, customer numbers) have been used to ensure the model is transferable to other UK electricity distribution network operators, and in earlier work we tested the approach on the National Grid transmission network. The work is already shown to be of interest to other sectors and internationally (see What Next?).
First Year Of Impact 2017
Sector Energy,Environment
Impact Types Societal,Economic

 
Description Appointed to National Infrastructure Commission Technical Expert Group
Geographic Reach National 
Policy Influence Type Membership of a guideline committee
Impact I advise the National Infrastructure Commission on their infrastructure planning and policies.
URL https://www.gov.uk/government/organisations/national-infrastructure-commission
 
Description Chaired the Infrastructure Section of the 2017 UK Climate Change Risk Assessment (CCRA)
Geographic Reach National 
Policy Influence Type Membership of a guideline committee
Impact The CCRA conclusions were accepted by government. They are currently developing an adaptation strategy to address the risks identified.
URL https://www.theccc.org.uk/tackling-climate-change/preparing-for-climate-change/climate-change-risk-a...
 
Description National Infrastructure Commission
Geographic Reach National 
Policy Influence Type Gave evidence to a government review
URL https://www.gov.uk/government/organisations/national-infrastructure-commission
 
Description Richard Dawson appointed to UK Government's independent Committee on Climate Change
Geographic Reach National 
Policy Influence Type Membership of a guideline committee
Impact The committee provides independent advice to government. They oversee the 5 yearly climate change risk assessment, mandated by the 2008 Climate Change Act and assess the UK's progress in terms of adaptation to climate change impacts.
URL https://www.theccc.org.uk/about/asc-members/
 
Description TERSE: Techno-Economic framework for Resilient and Sustainable Electrification
Amount £1,024,786 (GBP)
Funding ID EP/R030294/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Academic/University
Country United Kingdom
Start 05/2018 
End 04/2021
 
Description Met Office 
Organisation Meteorological Office UK
Country United Kingdom 
Sector Public 
PI Contribution Research expertise and case study problems
Collaborator Contribution New modelling data from high resolution climate model
Impact Ongoing
Start Year 2016
 
Description Northern Powergrid Collaboration 
Organisation Northern Powergrid
Country United Kingdom 
Sector Private 
PI Contribution Results and new analysis
Collaborator Contribution Data, expert knowledge, access to modelling tools
Impact Ongoing
Start Year 2016
 
Description Presentation at the Resilient Infrastructure 2018 Conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact Presented research on infrastructure resilience from the STRAIN project
Year(s) Of Engagement Activity 2018
URL http://resilienceconference.ethz.ch/
 
Description Project workshop 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Industry/Business
Results and Impact Introduce project and set out research priorities
Year(s) Of Engagement Activity 2016
 
Description Project workshop with Northern Powergrid 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Industry/Business
Results and Impact Project workshop to disseminate key findings from project to main industry partners
Year(s) Of Engagement Activity 2017
 
Description Research dissemination workshop 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact Update on project progress, explore results, identify new research priorities.
Year(s) Of Engagement Activity 2016
 
Description Richard Dawson: Adaptation Sub Committe 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact Richard Dawson gave a briefing to the Adaptation Sub Committee of the Committee on Climate Change on Climate Change Risk Assessment and Infrastructure Interdependencies.
Year(s) Of Engagement Activity 2017