What is blue e³?

Blue e³ is the registered trade name used by EREA Energy Engineering to distinguish energy-efficient transformers from traditional transformers. It is pronounced "blue triple e" – “triple e” stands for “EREA Energy Efficiency”.


The 2030 climate & energy framework goals are aimed at a 32,5 % increase in energy efficiency by 2030. Industry is being asked to improve product energy efficiency. This implies the need to achieve at least the same output with less energy.

Join us in the blue e³ world

The launch of the blue e³ product line is EREA Energy Engineering’s response to the 2030 goals. All blue e³ products, whether standard or custom-made for our customers, are developed so as to considerably reduce energy loss. This increased yield translates into euros thanks to the energy savings made during the life span of the product. So the economic value of a blue e³ product is more than just the initial purchase price. The economic value is equivalent to the initial purchase price minus the energy that the product will save.

The EREA blue e³ energy saving insolating transformers (SPT/BTE series) can also be used within the framework of the AREI Art 104 –vital current paths. This is how an isolated system is created to the secondary (IT floating system). Because of isolation monitoring, a first isolation error is detected early on and thus guaranteeing a very high safety level with regard to users, buildings and equipment.


  • Lower operating costs through reduced losses
  • Reduced voltage drop under full load
  • No problems from higher ambient temperatures
  • Also suitable for use as a isolating transformer

Translating words into action

EREA Energy Engineering has set itself the task of mustering like-minded businesses and associations. Companies and associations with similar ideas are getting together with EREA Energy Engineering to promote blue e³ products on the market. The blue e³ charter upholds these good intentions.

Discover the Blue e³-transformers from EREA.