LISBON, Dec 19 (Reuters) - Portugal's Galp Energia anticipates to begin producing biodiesel and biojet fuel from waste in an industrial-scale unit it is building at its Sines refinery in 2026, the company, which is primarily an oil producer and refiner, stated on Thursday.

Last year Galp participated in a 75%-25% joint endeavor with Japan's Mitsui to invest 400 million euros ($415 million) in the Hydrogenated Grease (HVO) plant, which will have a production capacity of 270,000 metric lots each year.

It will transform waste products, such as utilized cooking oils, into eco-friendly biodiesel and biojet fuel, also called sustainable air travel fuel (SAF), utilizing green hydrogen produced by an electrolyser powered by wind or solar energy.

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

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