Alternative transformer fluids for people and the environment

Reliable energy supply provided to shopping center thanks to “green” ester-filled transformer. Safety for people and goods –  and even environmentally friendly. When building a transformer for the power supply of a large shopping center, some prerequisites need to be met. Therefore the Shopping Center New World was chosen for a power transformer filled with natural ester, an environmentally friendly and operationally safe alternative to conventional mineral oil.

Reliable energy supply for large shopping center

A secure power supply is indispensable for a shopping center.  This is also the case for the New World shopping center in the Ningbo, Zhejiang Province. A transformer was needed to reliably transport electricity from a subway station to the shopping center – and fulfill an important prerequisite: high safety for people and the environment. 


Normally, transformers are filled with mineral or silicone oil for electrical insulation and cooling. However if there is any leakage, it is harmful to the environment and easily combustible. With the transformer for the shopping center an alternative fluid had to be put in place that is on the one hand biodegradable, and on the other hand hardly flammable. However, the change of the insulation fluid calls for an expert to adjust the transformer to the specific characteristics of this component. Siemens Transformers has been driving this technology for decades and has profound expertise in the design and manufacturing of ester-filled transformers.

Natural ester-filled transformer

The customer, a leading energy company in China, chose two units of 50MVA / 110kV transformers from Siemens. Compared to mineral oil filled transformers they contain vegetable and naturally biodegradable ester oil, which has a high flame and flash point. That they are environmentally friendly, and highly safe for people, makes them particularly suitable for facilities and buildings which necessitate a high degree of fire protection, for example hospitals, schools, airports and even shopping centers. It is also the first choice for places where high environmental standards are required, such as offshore wind platforms.

Environmentally friendly and high operational safety

The units will be delivered to the customer in December 2018, the installation will be finished at the end of that month. "Thanks to the transformer with natural ester oil filling, the power supply for the shopping center is not only reliable, but also safe and environmentally friendly," comments Dr. Beatrix Natter, CEO of Siemens Transformers.