Too much water, or not enough: why climate change could threaten our power supplies
It’s 2035, and severe flooding has hit the country once again. As the waters inundate electricity substations, hundreds of thousands of homes suddenly lose power. Desperate customers try and telephone the network companies – but no-one’s picking up.
The Intergovernmental Panel on Climate Change (IPCC) predicts climate change will increase the incidence of both extreme rainfall events and very hot summers in this country. Both could potentially pose threats to our power supplies – and the power companies are working with government to try and protect customers from more power cuts in the future.
But it’s not just the electricity system that needs to be prepared. Changing weather patterns could hit our systems across the board – transport, emergency services and telecommunications systems included – and they all need to cope.
Defending against water and storms
The government identifies flooding and high winds as two of the most significant risks threatening the country’s power supplies.
During this year’s storms, most power cuts have happened as a result of high winds bringing trees down onto power lines, according to industry group the Electricity Networks Association (ENA). But homes can be cut off in other ways. In 2007, an electricity substation in Gloucester was nearly flooded. If it had been, 500,000 consumers would have been cut off at a stroke.
The 2007 floods worried the government, prompting it to commission planning expert Sir Michael Pitt to review what needed to be done to improve the nation’s defences. Sir Pitt’s report identified protecting power and water supplies as one of six key priorities.
In response, the energy industry organised a ten year programme to improve flood defences for electricity substations. Oxford University Professor Jim Hall, an expert on how the nation can adapt to changing conditions as the climate warms, tells Carbon Brief, “although it’s not all the way there yet”, the electricity industry has made significant progress in defending itself against future flooding.
The research isn’t clear on whether climate change will lead to more high winds and pose a greater threat to power lines, according to the ENA. It says it’s currently working on a project with Newcastle University on this issue.
So while the power sector may have come under fire in recent months for allowing power cuts from storms, it’s clearly taking some action to protect itself against the future storm and flooding damage.
Not enough water
While the power system is making progress preparing for too much water, it could also suffer from too little of it.
Power stations need a lot of water to cool down. And they may need more in the future, as different technologies are brought into use. Carbon capture and storage (CCS), which the government wants to use to reduce emissions from gas- and coal-fired power stations, is extremely water intensive, for example.
The government’s plans for expanding the use of CCS, combined with increased energy demand, could more than double the amount of freshwater the sector uses by the middle of the century, according to a new paper co-authored by Professor Hall.
Government plans to bring exploiting the nation’s shale gas resource could also have an affect on supplies, as the extraction process uses a lot of water. Industry group Water UK recently signed a memorandum of understanding with the water industry in order to mitigate the “potential risks to water and wastewater services” from the shale gas industry.
Climate change could also make water scarcer in this country as the century progresses. The projections the government uses suggest climate change will lead to hotter summers. What will happen to rainfall is less certain. A few models suggest that could get wetter, but on the whole scientists think drier summers are more likely.
If the country needs more water, it’s not really clear where it’s going to come from.
Cascade failures: it never rains but it pours
The power sector may be making strides in developing a response to climate change, but it’s relationship to other industries also needs to be considered.
Under government plans, different sectors – including the financial services industry, the health sector and the energy industry – are required to report on their preparation for future threats, including their response to climate change.
But it’s unclear if there is much communication going on between the different industries. While Professor Hall is complimentary about the electricity industry’s plans for responding to threats in the future, he says:
“I don’t get a strong sense that things are being joined up with a great deal of determination”.
This could be a problem – because when extreme events occur, the country’s infrastructure tends all to be affected at the same time. As a Royal Academy of Engineering report put it in 2011:
“Extreme events highlight the interdependencies in infrastructure as they are liable to lead to ‘cascade failure’ where the failure of one aspect of infrastructure, such as flood defences, can lead to other failures, e.g. flooded power stations leading to power cuts which thereby affect telecommunications networks.”
Or, to put it another way – flooding could prevent key staff getting the train to work at a power plant, affecting the power companies’ plans for how to protect it, or respond to affected customers.
Overall it’s clear the country’s power industry is taking steps to protect our energy system from extreme weather events. But it’s hard to know which risks are going to predominate in the future, because we don’t know for sure what effect climate change is going to have. And in the end, the greatest problem may result from a lack of integrated response across many different sectors, rather than a failure in this one.