With innovative technology and a global footprint, Exel Composites is transforming power transmission 

As one of the largest manufacturers of composite profiles and tubes made with pultrusion and pull-winding technologies, Exel Composites (Exel) is a global operator with a wealth of local and international knowledge spanning more than 60 years. With unrivaled expertise, a collaborative approach, and a global footprint, Exel’s solutions help customers save resources, reduce products’ weight, and improve performance and energy efficiency in a diverse range of industries including wind power, transportation, and building and infrastructure. 

Exel is headquartered in Finland and now employs more than 600 professionals around the globe, with sales, manufacturing, or R&D facilities in the UK, the US, Finland, Austria, China, and India. The business was established in 1960, by three chemists who began producing electric detonator caps, followed by carbon fiber brushes, and then, ski poles. Throughout the 1980s and 1990s, Exel continued to expand, and in the 2000s, the sporting division was sold to focus on business-to-business sales. In the following decade, Exel consolidated its market position by acquiring the Chinese company, Nanjing Jianhui Composite Materials, and Diversified Structural Composites in the US. 

Heini Kloster, Product Manager for conductor cores, elaborates on the company’s evolution: “With a long history in composites manufacturing, we produce many different profiles using continuous production methods like pultrusion and pull-winding and we’ve grown to be a publicly listed company with global coverage. We’ve always served a wide range of industries like transportation, buildings, infrastructure, machinery, defense, and energy. However, in recent years, we’ve seen significant growth in the energy segment due to global trends in electrification and the energy transition, which has led to new product categories like conductor cores. 

“Our solutions are tailored to each customer’s needs, but as a simple definition, we can produce any 2D shape in varying lengths. We use different materials for fibers in our composites, and our resin systems are also tailored in-house. For the energy sector specifically, we manufacture a lot of profiles used for electric insulation so naturally insulating glass fiber composites are suitable for this application. We approach our conductor core product relationships by providing a range of expertise to manufacturers, and tailoring the profile’s size, shape, and lengths to give the customer freedom to make their own conductor design.” 

In terms of sustainability, Exel has partnered with Fairmat, a producer of second-generation carbon fiber composites. “We first worked with Fairmat to recycle carbon fiber scrap from pultrusion and pull-winding processes at our Finnish sites in Joensuu and Mäntyharju,” Heini explains. “The scrap was mechanically processed into CFRP chips, used for structural reinforcement, impact surfaces, and other lightweight applications, using minimal energy. This partnership creates a second life for our carbon fiber waste, supporting our long-term goals to reduce both waste and emissions.” 

Heini then turns her attention to the company’s recently conducted extensive market study, which was completed alongside several stakeholders from different regions related to electrical transmission, including the transmission grid owners (TSOs). “In Europe, the challenges of the electrical infrastructure are mainly related to ageing grids, inadequate transmission capacity, and increased sustainability requirements,” she explains. “Unlike here in Finland, most European countries are quite densely built, and the land is privately owned and in use, meaning it can be difficult to build new lines and projects like this can sometimes take over a decade! 

“Therefore, the most promising and interesting solution is to reconductor the existing lines with advanced conductors. This retains the existing structures, with the capacity increase coming from the new conductor having more conductive material and being more efficient. Different countries, however, have their own challenges, including density of population, fluctuating terrain from fjords to mountain ranges, or the long transmission distances from production to usage.” 

Commenting on Exel’s partnership with De Angeli Prodotti (De Angeli), Heini says: “Our partnership with De Angeli is very important for us, as well as other conductor core manufacturers we’re partnering with. As we’re focusing only on the composite component of the complete conductor, we’re partnering up with conductor manufacturers, who’ll take care of the conductive part of the conductor and put the actual conductor together. De Angeli was one of the first to approach us to supply these composite rods to be incorporated into their conductors and since then, we’ve done extensive technical development together for these advanced conductor products, for both single and multi-wired cores. 

“Compared to traditional steel core conductors like ACSR, composite core conductors are stronger, yet lighter, carry electricity more efficiently, and withstand higher temperatures without elongating. Generally speaking, conductor cores can be divided into two categories: single wire and multi-wire cores, but both include several variations. The sensitivity of first generation single-wire conductor cores caused De Angeli to develop the ACCS-Sens conductor, where single-wire core is combined with optical fibers to ensure its integrity during and after installation. Second-generation multi-wire conductor cores alleviate worries about structural sensitivity and integrity as their flexibility is comparable to the traditional ACSR. For many TSOs, this makes them a more favorable solution.” 

Turning to the future, Heini shares her thoughts on what’s next for Exel and the wider sector. “We’re constantly developing our products and production processes to meet the industry’s evolving requirements, and we’re actively working with different communities shaping the future of the transmission industry, such as CIGRE and IEC,” she says. “In May, we’ll be presenting a technical paper at CIGRE symposium in Trondheim, Norway, for instance, where we describe a study that showcases the reliability of the multi-wire core. The topic was proposed by Belgian TSO, Elia, and we conducted the study with De Angeli to show what happens inside a multi-wire core if an individual strand gets damaged or broken. 

“Interest towards composite core conductors is growing in different regions, and as more TSOs are starting to prototype these products, more experience is gathered and shared between them, making these solutions more attractive and adaptable. I firmly believe that pultrusion is the best way to produce conductor cores, which are needed in long lengths and uniform quality. Pultrusion processes love these kinds of products as that’s when they get to highlight their advantages, so I see Exel’s expertise in this method, combined with global production capacity, being a key attribute in supplier decisions. 

“In five years’ time, I’d also like to see the industry guiding IEC standardization from technical specification to a verified standard, as that would be a welcomed addition to the tool kit of comparing different composite core solutions,” Heini concludes. “The industry has rapidly evolved in recent years, so I expect us to have several lines up and running over the next few years.”  

https://exelcomposites.com