During spring 2025, the company renewed parts of its 20 kV overhead network, moving aging power lines from forested areas closer to roads for easier maintenance and reliability. For the new 7+ kilometer line, Ensto’s latest composite insulators were selected to help ensure a durable and modern grid for decades to come. The upgraded line aims to further improve network reliability and make fault detection faster and easier.
Composite as Part of a Modern Grid
The choice to use composite line post insulators was a clear one for Lappeenrannan Energiaverkot. Project Manager Jarno Kähö explained that they were immediately interested after learning about the product:
“This has been a much-anticipated innovation. Composite enables the construction of stronger and more reliable power networks.”
That anticipation paid off in spring 2025, when Ensto’s new composite insulators and matching crossarms were completed just in time for installation in the Savitaipale project. The grid contractor, Eltel, was the first to install the new solution.
Eltel’s Project Manager Mikko Rautio was impressed by the technology: “Switching to composite is a step into the modern age. Installation is easier when we no longer have to worry about fragile porcelain insulators breaking during assembly or in use.”
Jarno Kähö from Lappeenrannan Energiaverkot, Ensto's Marko Siira and Eltel's Mikko Rautio in Savitaipale, Finland.
More Durable, Robust, and Reliable
The composite line post insulator is highly durable and reliable by design, making it a significant step toward more sustainable and modern overhead lines. This is especially important in Finland’s demanding weather conditions, where insulators must withstand extreme temperature changes and storms.
Lappeenrannan Energiaverkot has been satisfied with their early experience with the product. Porcelain insulators are vulnerable to lightning strikes and mechanical stress, while composite insulators avoid these issues thanks to their silicone-coated fiberglass core.
Familiar Ease of Installation
Ensto’s composite insulators include features like a plastic sleeve integrated into the top groove of the insulator, which enables easy conductor pulling – and thus no separate pulling wheels are needed. According to Rautio, Eltel’s installers gave positive feedback: “Installation into the new crossarm was easy, just like with Ensto’s previous products. The conductor also moved smoothly through the insulator.”
At first, the darker color of the insulator raised some questions, but once installed, it blended in well with the environment and was hardly noticeable.
Rautio noted that while this was their first time installing composite line post insulators, they would gladly use them again. Kähö agreed, and Lappeenrannan Energiaverkot plans to adopt composite insulators in future line projects.
Get to Know the Products
Lappeenrannan Energiaverkot in Brief
Lappeenrannan Energia is an energy and water utility group fully owned by the City of Lappeenranta, responsible for managing the local electricity, water, and district heating networks. Our goal is to become Finland’s first carbon-neutral energy and water utility. We aim to offer our customers the world’s best tap water, smart and secure networks, and locally produced heat from renewable energy sources. We employ around 120 skilled professionals across the water and energy sectors.
Lappeenrannan Energia’s subsidiary, Lappeenrannan Energiaverkot, is responsible for delivering energy and water to customers, as well as maintaining, managing, and developing the energy and water networks.
