Old Dog, New Tricks: Ensto Brings Innovation to Overhead Lines

While underground lines may be trendier, the overhead line business is thriving – with Ensto making noteworthy innovations.

Underground lines are all the rage. They're trendy and talked about everywhere. But they're not suitable for all situations and environments. Overhead lines are still the backbone of any electricity distribution infrastructure, and while they may be less fashionable, thanks to Ensto they are definitely not less innovative.

A growing business

In Europe, the OHL business is quite stagnant with only moderate room for growth. But look beyond it – to Southeast Asia, Africa, the United States – and the business has much more growth potential.

“Africa, volume wise, is as big as our sales to Finland, even though we don’t have our own presence in Africa,” says Harri Vaara, Head of Sales, Overhead Lines. “Since it’s just too expensive to go underground in rural areas, OHL will be the business of the future.”

Small, technical details

For Ensto to remain a key player in the OHL business, its products must grow along with the market. But just because OHL is a legacy technology, doesn’t mean that it should be low-tech.

"Ensto's OHL trump card is FCCS – fully covered conductor solutions – accessories that contain a lot of small, technical details that add up to something greater than the sum of its parts," says Petteri Pulkkinen, Head of OHL Product Management at Ensto. "We've developed a new insulator with a plastic insulator top clamp. Our materials are robust enough to last a half century. Our products are fully type-tested. We offer lots of complete structures, a handbook to help line designers, plus YouTube videos for installers. We have customer training to support customers in implementing their own specifications of a fully covered conductor solution."

What Pulkkinen describes as a lot of small, technical details done right, is complemented by one of Ensto’s highly innovative advances in OHL, line condition monitoring technology that was designed to solve problems the product management team saw while working with customers.

Smart Sensors for FCCS

“Petteri and his team had noticed issues with fallen lines while in the field with customers,” says Roman Jałoza, Ensto’s R&D Manager of the Smart Technology Team. “If the covered medium-voltage lines fall, even with no breakage, it’s still dangerous. We saw this problem and decided to investigate.”

Downed lines aren’t always easy to detect. If a tree falls or touches the line there isn’t always a highly visible arc or sparks, thanks to the covered conductor. Current safety guidelines call for crews to patrol thousands of kilometers looking for problems after heavy storms have passed. These crews operate via helicopter, drone, snowmobiles, or skis — expensive or time-consuming methods.

Ensto’s investigation led to the creation of the first Ensto smart sensor for FCCS using the internet of things (IoT) technology. "We are developing a family of sensors that use IoT mesh technology," says Jałoza. "The sensors communicate among themselves, then send data to the cloud where we have smart analytics and data crunching. If there’s a problem, the customer’s user interface – in PC or mobile, whatever they like – alerts them that there’s something wrong. The IoT mesh self-defines the structure, increases the solutions' robustness and scalability. Ensto Line Condition Monitoring System helps with daily maintenance, network capacity optimization, predictive maintenance and even fault detection. It's a revolution in the DSO business and it's the only solution of its kind in our target markets." Jałoza says the ultimate goal is a full range of sensors for both overhead and underground lines and accessories, secondary substations and transformers. "On the system level we want to have digital twins of the lines so the end customer can do condition monitoring and network capacity optimization – we're bringing IoT technology to the DSO business."

Thanks to a high density of sensors, faulty locations can be identified by the customer within 100 meters. This translates to improved reliability, fewer interruptions in service, and lower wildfire risk in dry areas. “It’s far more cost effective than underground,” adds Pulkkinen. “And FCCS pays for itself in the form of reduced faults, lower maintenance costs, and higher quality electricity.”

But Ensto’s FCCS product offerings and smart sensors have implications beyond just the customer. “This is a technology that could allow the industry guidelines to be changed,” says Jałoza.

The Porvoo pilot

Ensto’s smart sensors are not yet on the market, but they have been undergoing tests on a 200-meter, medium-voltage pilot line built in the forest next to the Porvoo factory in Finland. The R&D team has put the line through the rigors, even dropping trees on the line to test the sensors. What is more, we use the capabilities of our accredited Ensto Laboratory to verify the sensor operation in the most demanding conditions.

“We are fully committed to providing cutting-edge solutions and products that will revolutionize distribution network maintenance in the coming year,” says Jałoza. “We currently have two proof-of-concept installations underway, one in southern Finland and another in the north. The northern location was chosen to prove the robustness of the technology in the tough Nordic winters, and also gain knowledge about conditions of snow and ice.” It is clear that extreme weather has become a real and global challenge nowadays. “Our solutions are designed for whatever conditions come their way,” says Jałoza.

Harri Vaara says Ensto’s R&D work is a real differentiator when it comes to the competition. “We have fantastic testing facilities and an accredited lab to support our OHL business. It’s a real asset we should be proud of.”

Known and trusted

The smart FCCS technology makes sense for any market where there is snow or storms, a natural for the Nordic region. But Vaara says it makes sense for “anywhere you find trees, wind, or snow” – markets like Australia, California, Africa, Malaysia, and Indonesia, where extreme conditions threaten lines. Ensto’s work has already been recognized in California, where local DSOs are using Ensto drawings when they specify installation regulations.

“Ensto has been known for decades in overhead lines,” says Vaara. “Ensio Miettinen’s first factory was to produce for the OHL market, so we have 65 years of knowledge, experience, and solutions driven by customer needs that make us a globally known and trusted player.”