The €100 million, seven-year loan will also be used or fund the Nemo interconnector between Belgium and the UK.
The Stevin project will see the installation of a double 380kV line between substations at Zeebrugge – near the border to the Netherlands – 47km south-east of Zomergem, where it can be more easily distributed around the country.
The link will help integrate power generated from Belgium's growing offshore fleet. It will link to the modular offshore grid (MOG) system due to connect four offshore projects currently under construction or in development: 309MW Rentel, 252MW Seastar, 224MW Northwester 2 and 266MW Mermaid.
Work on the Stevin cables is ongoing and due to be commissioned by the end of 2017, Elia said.
"It is important that this energy is transmitted as efficiently as possible to the national network, and that is what this loan is all about," said EIB vice-president Pim van Ballekom.
According to Elia, the upgraded Belgian grid is also needed as part of the 1GW Nemo interconnector with the UK, currently under construction.
Work on the interconnector is due for completion in 2018. It will link the countries between Ramsgate, in south-east England, to Herdersbrug, north-west Belgium. Commissioning of the link is expected in 2019.
"The energy transition means that more and more thermal power-plants that emit CO2 are replaced by wind and solar energy. We consequently need more transport capacity to bring renewable energy to the consumer. Stevin will also enable the interconnection with the UK, which gives Belgium an even more central role in the European energy system," said Elia CFO Catherin Vandenborre.