High-voltage transmission components – from power transformers to instrument transformers – play a critical role in the global energy transition. Given the speed of electrification, compounded with the spread of renewable energy sources like solar and wind, the industry is facing significant challenges in meeting increasing demand for this equipment. Underscored by the limitations of existing production capabilities, the importance of strategic planning and investment in high voltage transmission technology and infrastructure has become progressively evident.
Aging Infrastructure and the Need for Modernization
A significant number of the current transmission grids were constructed decades ago, and are not built to meet these new requirements. Therefore, modernization is crucial and entails the use of advanced, high performance components that can ensure efficiency and reliability. This process is facilitated by HVDC technology as well as long haul AC transmission, which enables the transmission of electricity over long distances with minimal losses. It is therefore essential for linking power exchanges, offshore wind farms, and solar parks in isolated areas.

Balancing Practical Demands with Creative Innovation

As demand steadily increases, production facilities worldwide are experiencing capacity constraints affecting the development of necessary infrastructure. Additionally, the market for power transformers and components is experiencing challenges due to supply chain shortages. To ensure the functioning of modern energy systems, there is a growing need for technologies that are intelligent, reliable, and sustainable. Manufacturers such as the Trench Group are investing in the research and development of advanced solutions that can address the evolving needs of the energy transition and are significantly increasing their global output by adding capacities.

Transformer bushings as a critical key component
High-voltage condenser graded bushings are key components in modern electricity transmission and distribution networks, connecting power transformers or shunt reactors to busbars and transmission lines. They provide reliable insulation between high-voltage and ground while ensuring that high currents are transferred securely.

Key features and benefits of bushings:

• Electrical Insulation: Resin-Impregnated Synthetic (RIS), bushings effectively isolate the high-voltage conductor from grounded structures. This reduces leakage currents, mitigates risks, and extends the operational life of the whole equipment.
• Consistent and Reliable Power Transfer: Bushings ensure uninterrupted current flow from transmission lines into transformer systems, delivering the reliability expected in high-voltage networks.
• Mechanical connection: Bushings serve as robust junctions for coupling external high-voltage conductors with the transformer’s internal components, providing system stability.
• Optimized Electric Field Management: Through condenser-core technology, the electric field is shaped and distributed evenly.
• Environmental Protection: The external insulator serves as a robust protective barrier, blocking dust, moisture, and other contaminants from entering the transformer.
• Mechanical Stability Under Stress: By securing the conductor against movement caused by mechanical loads, ind forces, or electromagnetic effects, the bushings contribute to the long-term structural integrity of the transformer system.
• Enhanced Safety by Design: Materials used in bushings are non-flammable, fire-resistant, and non-hygroscopic, minimizing fire hazards and preventing moisture ingress.

RIS – The new standard for safe and sustainable high-voltage bushings

A key advantage of RIS is its explosion safety. Instead of a fragile porcelain housing, RIS infuses a robust composite insulator design made of glass fiber and silicone. Since RIS bushings are 100% dry, there are no hazards associated with the use of mineral oil or SF₆.

The condenser core consists of a synthetic nonwoven fabric impregnated with epoxy resin. Nitrogen-based foam material is used between this core and the insulator, keeping the entire bushing free of liquids and gases.

The advantages of RIS bushings over OIP bushings at a glance:

• Reliability and safety
  • No oil, no gas fillings, no leaks.
  • Fire-resistant and explosion-proof.
  • Outstanding resistance to aging.
  • Designed for a wide temperature range from -60 °C to +55 °C.
  • Reliable even in regions with increased seismic activity.
  • High current carrying capacity and reliable overload reserves.
• Easy handling and Low Maintenance
  • No oil changes, no draining, no time consuming inspections.
  • Lower life cycle costs for grid operators.
  • Flexible mounting in differen positions.
• Sustainability
  • Free of oil and SF₆ – no release of hazardous substances.
  • Reduced environmental impact over the entire life cycle.

Sustainability made measurable
With the increasing importance of Sustainability, the environmental footprint of technical components is also coming into focus. Life Cycle Analyses (LCAs) have proven that RIS bushings achieve significantly better results compared to RIP and OIP bushings.
In concrete terms, this means that over an assumed service life of 40 years
under realistic operating conditions, RIS implementations have a 45.8% lower carbon footprint than RIP implementations¹.

Challenges in the US energy system
The demand for energy in the USA is growing at a rate that was hardly conceivable just a few years ago. Security, resilience and flexibility of the grid infrastructure are key issues, driven by far-reaching changes:

• Growth of data centers
• Reshoring of production
• Increased use of electric vehicles
• Technological innovations
• Expansion of renewable energies
• Regional imbalances in the grid

Various factors are placing increasing demands on the US-power grid infrastructure:

• Age-related replacement needs: Many parts of the grid date back to the 1960s and 1970s.
• Geographical shifts: New industrial centers and metropolitan areas are emerging in regions that were not previously designed for high loads.
• Data centers and AI: The energy requirements of data centers are growing exponentially and require powerful high-voltage connections.
• Critical infrastructure: The power grid is increasingly seen as part of national security and must meet the highest reliability standards.

An analysis by McKinsey² underscores this development: After almost two decades without any significant increase in load, electricity demand in the US is expected to surge by more than 3% per year until 2040. The Environmental and Energy Study Institute (EESI)³ shows how quickly the importance of data centers is growing. In March 2025, there were already 5,426 data centers in the US, compared to just 1,000 in 2018.

Trench and HSP: Investing in supply security and future viability
The Trench Group is responding to this development with a firm commitment to the US market. HSP US, a part of Trench Group, is investing more than US$60 million in the construction of an bushings manufacturing plant in Charlotte, North Carolina. At the same time, a new HSP production facility in Canada was opened to bridge the construction period of the US plant and ensure security of supply throughout North America. The new US factory’s capacity includes AC bushings up to 800 kV and additional capacity for a possible future HVDC expansion.

New manufacturing capacity for high-voltage technology
With production scheduled to start in March 2026 and capacity gradually expanding to several thousand units per year, HSP US is soundly positioned as a key player in the North American high-voltage market. The new facility with full vertical integration is being built on approximately 170,000 square feet, complemented by a state-of-the-art high-voltage test laboratory.

The significance of this investment goes far beyond a mere expansion of
capacity:

• Strengthening grid security
• Supporting decarbonization
• A prerequisite for the digitalization boom

A key component of this endeavour is the transfer of technology and manufacturing processes from Germany. All training programs would be supervised by experts from HSP Germany.
Charlotte is a compelling choice of location for this facility due to its central East Coast location, excellent transportation infrastructure including proximity to ports and major highways, a supportive business environment with tax incentives and grants, a skilled and growing workforce, and access to advanced technologies and reliable energy resources.
Benefits for the region and society

• Over the next five years, more than 110 jobs with above-average salaries will be created.
• Regional suppliers, service providers, and educational institutions will benefit.
• The plant meets high environmental standards. It is supported by the Inflation Reduction Act’s 48C Clean Energy Program⁴.

Trench Group – leadership in high-voltage technology
The challenges of the energy transition require partners such as the Trench Group, which not only develops innovative solutions, but also has decades of experience and offers maximum reliability.The group’s history of energy technology:

• 1893: Founding of Meirowsky & Co., the predecessor company of HSP.
• 1906: Start of production of capacitor bushings
• 1937: Emil Haefely laid the foundation for Trench’s bushing business.
• 1960s: Tony Trench developed the first environmentally friendly air-core reactor

Today, the Trench Group is a leading global supplier of high-voltage bushings, coils, and instrument transformers with over 2,800 employees at nine production sites and five regional sales centers. The combination of proven manufacturing processes, consistent quality control, and practical testing ensures that every product meets the increasing demands of modern energy infrastructures.

REGENERA® – The Future of Sustainable Energy Transmission
The Trench Group believes that sustainability is not only an obligation, but also an opportunity to innovate, optimize, and future-proof energy transmission.
REGENERA® is that opportunity.
REGENERA® represents the Trench portfolio of innovative products and services designed to:

• Reduce environmental impact – Lower greenhouse gas emissions, support the circular economy, and ensure transparency through life cycle assessments.
• Improving safety and reliability – improving safety, eliminating hazardous substances, and ensuring reliable performance.
• Maximizing efficiency – reducing losses, optimizing energy consumption, and extending the service life of equipment.
• Ensuring compliance and future viability – regulatory compliance and futureproof energy transmission.

High-voltage bushings are essential to today’s energy systems, both in terms of design and long-term reliability. Trench has the expertise to comprehend these details and has the ability to offer thorough direction when required.

References:

• [1] https://www.hspkoeln.de/media/pages/rise-to-new-horizons/4c19f338ba-1721639867/whitepaper_ris.pdf
• [2] https://www.mckinsey.com/industries/public-sector/our-insights/powering-a-new-era-of-us-energy-demand
• [3] https://www.eesi.org/ar ticles/view/data-center-energy-needs-are-upending-power-grids-and-threatening-the-climate
• [4] https://www.energy.gov/infrastructure/qualifying-advanced-energy-project-credit-48c-program