Utility Week

24 | 28TH SEPTEMBER - 4TH OCTOBER 2018 | UTILITY WEEK Operations & Assets Targeting investment HV solid cable prioritisation means replacing only those assets that are at risk of failure. W e are committed to delivering a safe and reli- able service to our 8.2 million customers at the lowest possible cost. Our networks in London, the South East and East of England span more than 140,000km of underground cables, some of which have been in service for many years. Our aim is to invest in these assets to maintain reliable supplies and keep costs down for our customers. Sometimes it can be a challenge to understand exactly the cause of a cable fault on our network because several different factors such as environmental, electrical or mechanical issues all have an impact on life expectancy. Traditionally, age alone was used in deter- mining when to proactively replace cables. More recently we've developed a proactive and methodical approach for prioritising investment based on their performance. In order to achieve this, we set out to understand more about the condition of high voltage (HV) underground cables and to develop an HV cable prioritisation model. UK Power Networks' innovation team has developed a tool for HV solid cables that can help us identify HV cables for early replacements before their failure. We carried out detailed studies on HV underground cables and the reasons they had failed. This work enabled us to develop a methodology that assesses the condition of an HV underground cable, and proactively replace under- ground HV cables before faults occur. We're improving the reliability of the network and reducing disruption to customers by ensuring cable replacement is carried out at the right time. The HV solid cable prioritisation tool is now a key part of how we maintain a safe, reliable electricity network. Case study Maxi Faridi Innovation engineer, UK Power Networks follow-on projects working with stakehold- ers to test some of the findings. "We have got ideas for how we take some of the research forward and look much more into underground space and how we use that space. It's broader than just utilities – we're looking at basements, tunnels and so on," says Metje. "We need to think differently about the whole underground space. And that's including the surface up to about 50m. We don't currently understand the value of this space and how this could support urban living by moving functions from above ground to below ground." Taking a more holistic view of the sub- terranean space will be critical as more regions across the UK seek to deliver "smarter" cities by disrupting conventional approaches to planning, maintenance and investment. Van der Kleij believes that as part of this holistic approach, there is the potential for assets owners to share more information, thus benefitting individual utilities and the entire network. "The chal- lenge is that as individual organisations you work towards many different commitments, so it's not always possible to work closely together," he admits. "If we invested in a high level of assets in a certain area, it would be ideal to work in collaboration with all the other utilities that also have commitment in the network at that particular location so that you look at it collectively." Metje agrees that the way people live and operate in the cities of the future could hinge on successfully utilising the under- ground space as a holistic asset: "It's not just about the underground infrastructure that's already there, we need to treat the subsur- face space as an asset which has enormous value, if only we can harness it. "We need to really value this subsurface asset, not just for today but also looking for- ward. Assets in the ground nowadays have a life of 100-plus years… you really need to take a long-term view. "Can you use the potential of the under- ground space to deliver far better city liv- ing? That's what I think should be done, but not enough people think of that as a third dimension. They only look upwards and not downwards, thus neglecting the under- ground space and its enormous potential and value." While government and local authorities are urged to consider the underground space as a complete asset, utility suppliers should similarly consider their subterranean asset base and the co-ordination of co-located assets with increasingly joined-up thinking. The way in which underground asset invest- ment is planned, delivered, monitored and maintained in the future must be approached with a holistic view of the subsurface space. Failure to do so will be a serious impediment to creating the smart, sustainable and resil- ient cities of the future. Data challenges Data sharing and the accuracy of data is a big challenge. In Holland, the Cadastre is a land registry and mapping agency responsible for national mapping and maintenance of the country's reference co-ordinate system. Com- panies must record their buried infrastructure on the centralised system and the information is available predominately online. In contrast, much of the UK's data on underground assets is held individually by companies. However, it is important to note that there are far fewer utility providers in Holland. The proliferation of utility firms in the UK aer privatisation has resulted in a system that is more fragmented, and ultimately more challenging when it comes to data sharing. continued from previous page Taking a more holistic view of the subterranean space will be critical as more regions across the UK seek to deliver "smarter" cities. Utilities should similarly consider subterranean asset base and the co-ordination of collocated assets with increasingly joined-up thinking.

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