The media has given considerable attention to efforts aimed at mitigating climate change, but not so much has been heard about adaptation. John McKenzie, National Grid’s UK Gas Transmission Asset Engineering Manager, explains why this is an important principle in the fight against global warming.
What the weather might be in the future is the subject of a great deal of study in the UK. Most researchers predict hotter summers, colder winters, more flooding, more severe storms – generally more unpredictable weather.
Companies like National Grid have made firm commitments to do their part in tackling the causes of climate change. For our part, we have committed to cut our carbon emissions by 80 percent by 2050.
But what about dealing with those consequences of climate change that are affecting us now?
The changes we’re seeing in our weather are having a massive impact on our facilities and systems. For example, remember the floods in 2007, when England and Wales had their wettest May and June since records began in 1766?
That July, we were transfixed by the ‘battle for Walham’, when combined military and civil emergency services tried to prevent flood waters from the River Severn from reaching the electricity substation at Walham, Gloucestershire. At stake was the electricity supply to half a million people.
National Grid made the news with its ability to respond and keep the lights on. But while we were able to maintain supplies to our substations, the local electricity company lost supplies to 48,000 homes for two days. More than half the homes of Gloucestershire – 135,000 – were without drinking water for up to 17 days, and 1,950 people (including 490 children) needed temporary accommodation.
Meanwhile, in South Yorkshire, there were fears of a major disaster when cracks appeared in the dam at Ulley reservoir, near Rotherham. Nearby residents were evacuated and a section of the M1 motorway was closed as a precaution. It was a tense time for National Grid too. Downstream of this reservoir, we have critical infrastructure, including an above-ground gas installation and an electricity substation serving Sheffield, which could have been severely damaged had the dam given way.
We might think of each of these as a one-off, an exception; however, the list of incidents is getting longer, and they seem to be getting more and more common.
National Grid is responding to the challenge. We have invested in 1.7 kilometres of temporary flood defences, which are stored on a 40-tonne articulated lorry and can be deployed anywhere quickly.
We regularly work with DEFRA on identifying and planning contingencies for potential flood risks. At the moment we’re looking at some of the more vulnerable electricity transmission sites on the East Coast – we’ve already built permanent flood defences around some critically important installations.
Obviously there are costs involved, but we believe we’re getting the balance right with the permanent and temporary precautions that we’re taking.
More than flooding
Climate change isn’t all about flooding, however. National Grid feels the impact of higher summer temperatures too – especially on our electricity circuits – and of colder winters.
In the winter of 2010, at some of our sites in Scotland, we recorded temperatures of -210C, which put our compressor fleet under strain. Our operational teams did a marvellous job keeping air intakes clear so our engines could run and keep the gas flowing across the UK.
And it’s not just the deep freeze of winter that we’re watching. Soaring summer temperatures and changing patterns of consumer demand have prompted us to look at the engines on our gas transmission sites. As a result, we’ve changed their cooling systems on some of the sites so the engines will run more efficiently.
With the flooding and rainwater runoff in certain areas becoming more aggressive, we are experiencing increased river erosion. This is causing us to adapt by looking at how we lay our pipelines across rivers and estuaries so they will be secure for the future.
Now, instead of using the open-cut method of trenching to lay pipes or cables below the bed of a river or body of water, we’re looking at directional drilling. This will bury the infrastructure a long way down, so it’s undisturbed by changes to the water course.
The challenges are vast for National Grid as we design, procure and build the nation’s infrastructure.
We need to meet the demands of our customers not just for today, but for the next 40 years. Our challenge is to ensure our systems and assets can cope with whatever the weather throws at them, now and in the future.