A ticking time bomb? Why we should be talking about our ageing transformer fleet
It takes a lot to keep the lights on. Fuelled by global population growth, increased per capita consumption of energy and the growing proportion of energy supplied as electricity, energy demand is on the up, and so is the world’s appetite for an uninterrupted power supply.
In the US and Europe, an industrial growth boom from the 1950s to 1980s led to significant investments in critical infrastructure, particularly in electrical power grids.
But while demand for power has continued to rise, those investments have failed to keep pace, and the number of new transformers – vital cogs in the electricity transmission machine – has actually been in decline.
Skyrocketing costs have been a key factor; the average transformer cost has risen by 5.5% annually for around 20 years, equivalent to a 100% increase in the cost of a transformer every 12-15 years.
An ageing population
Deterred by these costs, owners have been postponing capital investments. Rather than upgrading the transformer fleets, they are ever more reliant on existing assets coping with a job that becomes more demanding with each passing year.
But an ageing asset population cannot be ignored. As they move through their life cycles, transformers require costly utility component replacements and safety system maintenance, while the very real threat of failure grows stronger.
Growing with this risk of transformer failure is an even greater threat: transformer fire. The impact of such a blaze can go far beyond asset failure and loss – with power outages, evacuations of the surrounding areas and even risk to life in urban areas.
A fluid solution
Changing the type of fluid used in transformers could play a vital role in mitigating this growing fire risk and extending the life of transformers.
For many years, mineral oil has been used both for cooling and electrical insulation in transformers.
It has been largely effective, but rising electrical loads in power transmission equipment have exposed the shortcomings of this fluid – most notably its inherent potential flammability.
Where performance used to stand as the primary goal, safety has now joined it at the forefront of the transformer agenda, and with it the demand for fire-safe transformer fluids is growing.
An alternative to mineral oil, synthetic and natural ester fluids can meet both the performance and safety demands of the ageing transformer fleets. Their use can also defer the cost of new transformers while enjoying the benefits of fire safety and environmental protection.
Ester fluids are fire-safe, and eliminate the risk of transformer fire. With a high moisture tolerance, they can absorb greater amounts of water than mineral oil, and even allow transformers to run safely at higher temperatures.
In addition to addressing this fire risk, ester fluids will, by extending the life of the insulation paper, also extend the life-cycle of transformers, easing the challenge of costly infrastructure upgrades and ensuring that the lights don’t go out.
By Barry Menzies, Managing Director MIDEL Dielectric Fluids Global