Paula Díaz and Oscar van Vliet

IDRiM Isfahan, 03.10.2016

Resilience of Electricity Transmission grids

▪  Discuss some drivers for change in electricity grids that influence the development of grid over the next decades

▪  Focus on how the drivers become more important in the face of climate change and an increase in extreme weather events

▪  Update to existing work on adaptation of electricity infrastructure (e.g. Sieber (née Schulz) 2011)

Objective

HV Power line in France after a storm in 2009 Source: http://www.gettyimages.pt

▪  Total demand is growing slowly, by ~0.5% per year (Eurostat)

▪  Building new lines is expensive ▪  Building new lines is time consuming ▪  The grid is trimmed for financial efficiency

General trends in electricity demand

Lower transmission capacity margins

▪  As production of renewables increases, transmission grid will move more electricity further away

▪  Increasing likelihood of climate-induced migrations, causing: ▪  Transmission system operators (TSOs) will pay reparations

in some places with damaged infrastructure and shortage of clients

▪  Growing demand for electricity from impoverished migrants in others places

Climate-induced trends in electricity demand

▪  Approx. half of past outages are due to weather

Vulnerability of the grid to climate change and natural hazards

Source: E.ON, via Boston, 2013

▪  Future climate with more extreme events will lead to a correspondingly larger number and more extensive outages

(Ward 2013).

13-year analysis of weather outages in Finland

▪  Successfully operation of the grid in extreme circumstances

▪  Redundant links ▪  Isolate outages ▪  Restore services ▪  Repair & rebuild infrastructure

Resilience seems to conflict with most of the current grid trend

Resilience in electricity networks

4 Pillars

Concept: Multiple ways of getting to each destination ▪  Transmission grids operate with an n-1 redundancy (or more) ▪  Extra corridors will be exposed to the same weather events

by geographic proximity à risk of concurrent failures

1. Redundant links

Concept: sacrifice part to save the whole ▪  Avoid natural hazards turning into cascade failures ▪  How to build a decentralised and integrated grid?

Challenges: Complexity ▪  Less ‘network mass’ for demand shifts ▪  Expensive additional equipment ▪  Possible new power lines

2. Isolate outages

Concept: Get electricity flowing again as soon as possible ▪  Duration matters: 15 second is a glitch, 15 minutes is usually

fine, 15 hours is bad, 5 days can be lethal ▪  Impact depends on place, season and service

Challenges: Logistics, funding ▪  How to have sufficient equipment (generators, …) available? Climate change: If outages will become more prevalent ▪  May help in mobilising more resources for disaster

management ▪  Sparsely populated areas have lower priority in response

3. Restore services

Concept: Get electricity flowing for the long term ▪  TSO reroutes power and/or rebuilds network

Challenges: Logistics and resources ▪  Grid equipment is typically specialised and large, and some is

custom-built. ▪  Large transformers are rare or unique, leads to long delays ▪  If we standardise parts, how to avoid ‘monoculture’ risks?

4. Repair & rebuild infrastructure

Repair & rebuild infrastructure

Source: www.alamy.com

Source: www.tdworld.com

▪  The trends in electricity production ▪  Demand under climate change conditions ▪  Improvement of grid resilience

Challenges: ▪  Public acceptance ▪  Permit procedures in the EU often take 6-7 years (up to 20) ▪  ENTSO-E plans 10 years ahead, but national TSO implement ▪  Expert-driven processes, often low on the Arnstein ladder

Grid Expansion Require

new power lines

▪  Physically adapting the grid to shifting centres of demand and supply is not a matter solely for technocrats and engineers

▪  Grid vulnerability can be reduced by sharing best practices

▪  Efforts by scientists and some TSOs to do participatory processes had encouraging results

▪  Adapting the grid to mitigation and effects of climate change is primarily a challenge of management and communication

Conclusions

Thank you

Paula Díaz Paula.diaz@usys.ethz.ch

This research project is part of the National Research Programme "Energy Turnaround" (NRP 70) of the Swiss National Science Foundation (SNSF). Further information on the National Research Programme can be found at

www.nrp70.ch.