Increasing the capacity and resilience of overhead power lines
Increasing the capacity and resilience of overhead power lines
This startup is turning to robotics and advanced material science for more cost-effective uprating
Innovators like SuperNode and SUBRA are developing next-generation superconductor technologies. But boosting existing technologies and uprating overhead lines is also essential – not least because renewable electricity targets are imminent, and superconductors are several years away from widespread commercialisation.
Boosting overhead capacity today requires the building of brand-new lines or the replacement of the wires and cables that make up existing lines. Both options are expensive and require heavy engineering that involves complex planning and outages. Now, however, UK company AssetCool is providing a more cost-effective option for capacity expansion by tackling challenging ‘surface phenomena’ that constrain capacity, reduce the lifetime of infrastructure, and cause other unwanted side effects, such as noise pollution. The startup does this through a suite of functional power line coatings that can be applied in the factory or retrofitted to existing infrastructure using advanced robotics.
"‘When it comes to overhead conductors, higher temperatures result in lower capacity, so cables that operate at lower temperatures for a given cross-sectional area and current are preferable."
When it comes to overhead conductors, higher temperatures result in lower capacity, so cables that operate at lower temperatures for a given cross-sectional area and current are preferable. The key parameters that influence these ‘thermal capacity’ constraints are the rate at which a line absorbs incoming solar radiation (solar absorptivity) and its effectiveness at emitting heat (thermal emissivity). Two of AssetCool’s products (SE01 and SE02), optimise these parameters to passively cool overhead conductors, thereby boosting capacity by up to 30% while reducing losses by up to 10%. SE01 is designed for factory application, while SE02 is a retrofit solution.
Corrosion, meanwhile, reduces efficiency and increases the risk of power failures – particularly when lines are installed in extreme environments, such as coasts and deserts. To address this, AssetCool has developed SE03, an anti-corrosion product that can be applied to existing lines. This uses three different techniques to protect cables from corrosion, reducing maintenance issues.
AssetCool has applied its SE02 coating to a 132-kilovolt line in Alberta, achieving a transfer capacity increase of
AssetCool has applied its SE02 coating to a 132-kilovolt line in Alberta, achieving a transfer capacity increase of
Power lines can also create noise, particularly in wet weather conditions, where water droplets form on the lines – a phenomenon known as “wet audible corona noise”. This noise can breach regulations and cause disruption for neighbouring communities. AssetCool’s inorganic nano-coating, SE05, reduces noise by altering the surface properties of lines to make them superhydrophilic. This means that water rapidly and uniformly spreads across the lines’ surface rather than forming droplets.
Through partnerships with cable manufacturers, AssetCool is developing efficient techniques for applying its coatings at point of manufacture. Its state-of-the-art solution, known as ‘CAM-ACU’, can achieve production speeds of 20 metres per minute, and the company’s products for new lines are already commercially available.
For existing lines, AssetCool has created CAPACITY-N, its advanced robotic system for applying coatings in the field. This system has already been tested through several pilots, with commercial projects in the pipeline.
AssetCool has applied its SE02 coating to a 132-kilovolt line in Alberta, achieving a 20-megawatt increase in transfer capacity without reconductoring. It has also demonstrated SE02 on a test line in partnership with Slovenia’s transmission company Eles. In this test, the coating resulted in a 20% capacity uplift, verifying the technology’s performance in European conditions. The company’s noise-reducing SE05 coating, meanwhile, has already been deployed in a nine-kilometre project in the UK, and is currently being scaled up, with the SE03 corrosion coating also set to be rolled out with utilities facing corrosion problems.
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AssetCool’s technology is applicable to both distribution and transmission. The startup’s products for new lines enable cable manufacturers to produce higher performance and more efficient conductors for the grids of tomorrow. Its retrofit solutions, meanwhile, are also set to play a crucial role by uprating the capacity of conductors without the need for costly rebuilding of transmission and distribution assets. In fact, the company estimates that CAPACITY-N could reduce costs by 90-95% compared to reconductoring, while also reducing outage time by 80-90%. Once fully commercialised, AssetCool could help DNOs and TSOs rapidly and cost-effectively expand the capacity of their networks in response to surging demand.
