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Customer Success Story

REC Solar in Singapore monitors transformers in real-time with digital solutions from Hitachi Energy

REC Solar in Singapore monitors transformers in real-time with digital solutions from Hitachi Energy


Once installed solar photovoltaic panels provide clean energy for decades; their manufacturing however is an energy intensive process requiring reliable power supply. 

Transformers are critical assets in electrical networks. They are designed for decades of operation but the probability of failure increases with age. 

REC Solar[1], is a multinational solar energy company, it has about 10,000 megawatts (MW) of installed capacity worldwide. Reliable and quality power supply is critical for it to maintain high quality in the solar photovoltaic panels being manufactured at its facilities worldwide.

Customer Highlights

“Thanks for introducing the valuable online monitoring product CoreSense™ M10, which is helping us to detect possibility of premature failure and the status of critical transformer health in real-time”, said Padmanabhan Sivakumar, Senior Electrical Engineer of REC Solar, Singapore. “I certainly believe that for major distribution systems it is good to equip transformers with digital monitoring and diagnostics. This will develop the organization’s confidence on power supply reliability and provide business continuity".


With the objective of ensuring high power supply reliability at its manufacturing facility in Singapore, REC Solar has adopted online monitoring and diagnostics sensors from Hitachi Energy for the two 75/95 MVA transformers at the unit. Digital sensors will enable continuous monitoring of gases being built-up in transformer oil – a major indicator of transformer health. The TXpert™ Ready CoreSense™ sensor[2] will be used for continuous monitoring of hydrogen and moisture levels in the oil of both transformers - the first warning indicators of deterioration in transformer health. The TXpert™ Ready CoreSense™ M10 that can measure nine gases has been mounted on a  movable skid and provided as a Nursing Unit. When the CoreSense™ indicates high hydrogen levels in any one of the transformers, the Nursing Unit will be quickly moved to it for a more detailed analysis, giving high flexibility to monitor both transformers with one multigas sensor. The Nursing Unit can also be offered as a service to support extending operations of a sick transformer until a scheduled shutdown.


For many years analyzing gases dissolved in transformer oil has been the method for transformer diagnostics, detectiong incipient faults and checking suspect transformers. Samples are taken manually typically once a year or once in 6 months for laboratory analysis.

Compared to the above time-based methodology continuous gas monitoring with digital sensors has major advantages, greatly reducing risk of unplanned incidents and costly consequences of related outages. It provides valuable input to plan for maintenance, repair or replacement for aging transformers.

The CoreSense family of DGA sensors are part of the TXpert™ Ecosystem for digitalization of transformers. The ecosystem is open, scalable and manufacturer agnostic with a complete suite of products, software, services and solutions.


[1] REC Group is an international pioneering solar energy company dedicated to empowering consumers with clean, affordable solar power in order to facilitate global energy transitions. Committed to quality and innovation, REC offers photovoltaic modules with leading high quality, backed by an exceptional low warranty claims rate of less than 100ppm. Founded in Norway in 1996, REC employs 2,000 people and has an annual solar panel capacity of 1.8 GW. With over 10 GW installed worldwide, REC is empowering more than 16 million people with clean solar energy. REC Group is a Bluestar Elkem company with headquarters in Norway, operational headquarters in Singapore, and regional bases in North America, Europe, and Asia-Pacific.

[2] CoreSense™ gives continuous online monitoring of a single transformer gas (hydrogen) and moisture. It monitors hydrogen levels in transformer oil to provide an early warning for most incipient transformer faults and complement traditional offline laboratory Dissolved Gas Analysis (DGA) of the transformer oil. CoreSense™ M10 provides real-time, continuous, online monitoring of dissolved gases and moisture levels in transformer oil. It measures nine gases: hydrogen, methane, acetylene, ethylene, ethane, carbon monoxide, carbon dioxide, propane and propene. Dissolved gas readings can be used to provide early identification and warnings for most transformer faults; whereas moisture monitoring can prevent premature aging of a unit. Early identification and detection of such incipient faults thereby allow you to take preemptive measures, when needed. Both sensors are qualified as TXpert™ Ready Sensors to connect with CoreTec™ 4, the TXpert™ Hub.