LISBON, Dec 19 (Reuters) - Portugal's Galp Energia expects to start producing biodiesel and biojet fuel from waste in an industrial-scale unit it is constructing at its Sines refinery in 2026, the business, which is mainly an oil producer and refiner, said on Thursday.

In 2015 Galp got in into a 75%-25% joint venture with Japan's Mitsui to invest 400 million euros ($415 million) in the Hydrogenated Vegetable Oil (HVO) plant, which will have a production capacity of 270,000 metric loads per year.

It will change waste products, such as utilized cooking oils, into eco-friendly biodiesel and biojet fuel, likewise understood as sustainable aviation fuel (SAF), utilizing green hydrogen produced by an electrolyser powered by wind or solar power.

Galp said in a statement it received on Wednesday the three reactors to process biofuels, which will permit the HVO unit to "produce SAF and biodiesel in 2026 ... positioning Galp at the forefront of developing low-carbon solutions essential for the energy transition".

Galp is also investing 250 million euros in a 100 megawatt (MW) to produce green hydrogen to power the refinery in Sines. ($1 = 0.9637 euros) (Reporting by Sergio Goncalves;-RRB-