As global demand for electricity continues to rise and energy grids modernise to accommodate renewable generation, the infrastructure that underpins power transmission has never been more important. From high-voltage substations to utility-scale transformers connecting solar and wind projects to the grid, reliable insulation and cooling systems are essential to the safe and efficient flow of electricity.
To support this expansion, Redox has welcomed Molekulis, a specialist distributor of transformer and specialty oils. Molekulis brings deep technical expertise and long-standing relationships across the energy sector, particularly in the supply of high-performance oils used in electrical transformers and related equipment.
These oils play a vital role inside transformers, acting as both an electrical insulator and a cooling medium. By dissipating heat and preventing electrical discharge, transformer oils help protect the performance and lifespan of essential power assets. As electricity networks become larger and more complex, the need for high-quality insulating oils is set to grow.
Molekulis has supported a wide range of major energy and infrastructure projects across Australia and New Zealand. Over the past seven years, the business has supplied transformer oils to more than 100 solar and wind farms, along with dams, data centres, transmission line projects and distribution substations. Its work includes highly challenging and remote locations such as the Manapouri Dam in the South Island of New Zealand, where Molekulis has supplied every new transformer and is currently supplying oil again for the next round of installations. In Australia, the business has also supplied oil for a large number of transformers tied to Transgrid’s new transmission line projects, including Buronga in New South Wales, home to what is regarded as the largest substation in the Southern Hemisphere.
We spoke with Philippe Reboul, who leads the Molekulis business, about the role of transformer oils and the trends shaping the power sector.
Manapouri Power Station New Zealand
[Q: For those unfamiliar with the technology, what role do transformer oils play inside electrical transformers?
At first glance, transformer oils serve two critical functions: insulation and cooling. Inside a transformer, conductors carry very high voltages, so the oil acts as an electrical insulator to prevent arcing between components. At the same time, it circulates through the transformer and, where applicable, its cooling banks to remove heat generated during operation, helping keep the equipment running safely and efficiently.
However, the role of insulating oil goes well beyond these two functions. The oil must minimise electrical losses, remain compatible with rubber gaskets and all materials it comes into contact with, including metals, glues and paints, resist corrosion, avoid gassing, and meet strict safety requirements. International standards define a long list of characteristics that insulating oils must satisfy.
We often refer to insulating oil as the “blood” of the transformer. It is a highly specialised fluid that must remain within strict physical and chemical limits throughout the life of the asset. Oil samples are analysed regularly, not only to assess the condition of the oil itself, but also to detect trace compounds that can reveal the condition of the transformer, including signs of electrical or thermal stress.
Q: Why is the quality of transformer oil so important to utilities and energy companies?
The oil is fundamental to transformer performance over the long term. High-quality insulating oils maintain their dielectric strength over extended periods and resist oxidation and degradation. This directly affects the lifespan of the transformer, which is an extremely valuable asset for utilities and energy-intensive industries such as mining, smelting and chemical processing. Effective oil management can significantly extend equipment life and reduce maintenance costs.
Unlike engine oils, most transformers will never undergo a full oil change during their 20-, 30- or even 50-year service life. When oil replacement is required, it can cost tens of thousands of dollars, making it crucial to begin with a high-quality insulating oil from the outset.
This becomes even more meaningful when you consider where these oils are used. Molekulis-supplied oils are found in transformers powering Australian Antarctic bases from diesel generators, as well as at airports, train stations, ports, defence sites and major public infrastructure. They are also used in the new Western Sydney Airport, the Sydney Metro network, and data centres around Sydney and Melbourne operated by some of the world’s largest technology companies. Across Western Australia, many transformers used throughout the Pilbara mining region also run on Molekulis transformer oil. Even highly specialised facilities such as the WA radio astronomy observatory rely on transformers using these oils to support critical operations.
Q: What types of products does Molekulis supply to the market?
We supply a range of transformer and specialty oils, including mineral insulating oils and fire-resistant ester oils designed for demanding electrical applications. These products are used by utilities, industrial power users, transformer manufacturers, and service companies responsible for maintaining transmission and distribution infrastructure, as well as industrial facilities.
Photo of Buronga substation, part of Transgrid’s Energy Connect project (image curtesy of Transgrid)
Q: How is the global energy transition affecting demand for transformer oils?
It is having a very positive impact. As countries invest in renewable energy, electrification and grid modernisation, transformer installations are increasing significantly. Every wind farm, solar installation, battery storage facility and new transmission line requires transformers to step voltage up or down, or to convert between DC and AC in applications such as rail. This is creating sustained growth in the need for insulating oils.
The transition now underway also represents major capital investment by governments, utilities and private industry. These are long-life assets expected to perform reliably for decades, and transformers are central to that picture. At a time like this, specialised oils matter enormously because oils are not interchangeable. Transformer oils are carefully engineered to perform for the life of the transformer and beyond, while also meeting strict technical and safety requirements.
Q: Are there particular regions where you’re seeing strong growth?
Growth is occurring globally, particularly in regions investing heavily in renewable generation and expanded transmission infrastructure. The electrification of transport, data centres and industrial processes is also increasing power requirements, which in turn calls for stronger and more resilient electricity networks.
Q: What advantages does Molekulis gain from becoming part of Redox?
Redox brings a strong global logistics network and established relationships across a wide range of industrial sectors. By combining that reach with Molekulis’ specialist knowledge in transformer oils, we can support customers more effectively and help maintain dependable access to these critical materials.
That capability becomes especially important during periods of disruption. In times of crisis, such as during COVID-19 or amid ongoing instability in the Middle East, customers need confidence that essential products will remain available.
As market leaders, Redox and Molekulis are well placed to build robust supply chains and provide access to uncompromised, high-performance transformer oils when customers need them most. Redox also supports sustainability in this category, with mineral transformer oils able to be fully recycled into new transformer oil, something the company already does at its facility in New Zealand.
Supporting the Future of Energy
The acquisition of Molekulis strengthens Redox’s position in the energy sector, adding specialised expertise in transformer and electrical insulating oils to the company’s growing portfolio.
As investment in renewable energy, electrification and grid resilience continues worldwide, the role of dependable transformer technology will only become more important. With Molekulis now part of the Redox network, customers can access specialist product knowledge backed by a global distribution platform, helping support power infrastructure projects now and into the future.
Redox looks forward to working with Philippe Reboul and the Molekulis team to support the industries that keep electricity flowing safely and efficiently across modern energy networks.