How to optimise the cost of transformer use and save money
The targets of the 20/20/20 EU program led to general performances review of the transformers and introduction of the Ecodesign Regulation in order to ensure that new transformers put into service in the EU become progressively more efficient. The resulting energy savings have been estimated at 16 TWh per year from 2020 onwards, which corresponds to 3.7 Mt of avoided CO₂ emission.
Keywords: ecodesign, efficiency, losses, CO₂ emission, total owner cost
The targets of the 20/20/20 EU program led to general performances review of the transformers. The Ecodesign Regulation, adopted in 2014 and its new amendment adopted in 2019 by the European Commission, ensure that transformers become progressively more efficient as new power transformers are put into service in the internal EU market. Transformers have to fulfil minimum energy efficiency requirements starting from July 1st 2015. The second step in the energy efficiency improvement process is to be made in 2021. The resulting energy savings have been estimated at 16 TWh per year from 2020 onwards, which corresponds to 3.7 Mt of avoided CO₂ emissions. This is equivalent to saving half of the annual electricity consumption of Denmark (32 TWh per year). This review of performance, done by the amendment adopted in 2019, has also shown how the transformer specifications should be implemented to achieve economical benefits for the user. In this article, we will develop an approach regarding how to specify a transformer to optimise the total owner cost for the user by mastering the energy performance phenomena. The range of transformers in the EU is divided into 2 families, one for repetitive transformers in general with a nominal power less than 3,150 kVA, in which the standardization of components is relevant in terms of cost and another, without repetitive transformers (without series), in which the standardization components are not possible and not relevant. Therefore, fixed losses for transformer which have a rated power less than 3,150 KVA, identical components and optimal prices for the users have been chosen. The standardisation body has decided to introduce peak efficiency index (PEI) for larger transformers above 3,15 MVA to reduce the cost of use if the user is able to define its load factor well during the period when the transformer is in use.