Grid Resilience
How resilient is your grid connection? Most operators of key infrastructure are not aware of the risk of a grid failure from an external single point of failure.
Power Cut
30,000 homes and businesses off supply in London - where do you start?
In November 2015, a power cut hit West London with 30,000 homes off supply. Simon Gallagher, the senior executive in charge of the electricity network in central London and a hands-on electrical engineer was first on the scene.This 'High Impact, Low Probability Event' was resolved within just 2 hours, restoring supplies to all 30,000 properties. Simon Gallagher is now our Managing Director here at UK Networks Services and we still use the lessons learned from this event in our resilience assessments today.
Are you aware of your 'Single Points of Failure'?
The UK has one of the most reliable electricity networks in the world, which is operated in line with stringent security of supply standards. However, things can and do go wrong, which can lead to a loss of supply to critical national infrastructure. We find most infrastructure operators do not understand the resilience of their grid supply in terms of 'High Impact, Low Probability' events - often caused by hidden single points of failure which can be miles away from site.
These single points of failure are often hidden and upstream from the sites own infrastructure. Common examples we find:
- High voltage supplies from a common DNO substation
- High voltage supplies from a single bus bar or bus bar section
- High voltage supplies with the main supply as well as the back up in the same trench
- All supplies on site from a common substation
- No spares for critical single points of failures
- Transformers with no fire separation
When the single points of failure are identified, mitigation can be put in place to ensure they do not present an unacceptable risk. Mitigation can include permanent standby generation, high voltage interconnection and multiple independent grid supplies.
Kingsway, April 2015 - the classic 'HILP'
In 2015, a High Voltage (HV) cable faulted in a cable subway tunnel that ran under Kingsway, London. Possibly caused by other infrastructure damaging the HV cable, the electricity company's automatic systems isolated the faulted cable quickly and re-routed power, keeping the theatres and businesses in the West End on supply. Unfortunately, natural gas in the the subway caught fire causing a major incident.
Within the same subway were x4 oil filled Extra High Voltage (66,000 V) cables that supplied all the power to a critical electricity company substation, as well over 20 High Voltage (11,000 V) cables that then distributed this power to the local area. All were destroyed in the fire, which burned for 3 days.
For this incident, Simon Gallagher (UKNS Managing Director) was the on site incident commander for the electricity company. On the first night, over 400 engineers worked to connect more than 50 large generators and build a new high voltage network across the streets of London to restore power. This had never been attempted in the capital before.
This is a classic 'high impact, low probability' event that network operators risk with single points of failure.
How we can help
Resilience Report
Mitigation Cost Benefit Analysis
Disaster Recovery
We can analyse both your on and off site electrical high voltage infrastructure and identify single points of failure From this analysis we will create 'High Impact, Low Probability' scenarios. Authorised by all DNOs in Great Britain to design their networks up to 132kV, we are the true experts in the field.
Once the level of risk has been determined, mitigation can be put in place. Key to the decision on what mitigation to put in place is cost - the cost needs to be considered alongside the risk rating and the economic cost of power failure. We provide full costings for the identified mitigation to allow informed decision making.
How long would it take to recover operations after a power cut? We help you put in place operational plans to enable a quick recovery. This could involve upgrades to your private HV network to allow rapid re-configuration or pre-prepared contracts for emergency generation to be deployed quickly to pre-prepared sites.
We are the experts.
UK Networks Services is internationally recognised as the leading experts on the grid, having provided in-depth commentary and detailed analysis on air for Bloomberg, The New York Times, CNN, BBC News, Times Radio, The Today Programme, Channel 4 News, the Financial Times and The Economist.
