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 mostly an oil manufacturer and refiner, said on Thursday.

In 2015 Galp participated in a 75%-25% joint venture with Japan's Mitsui to invest 400 million euros ($415 million) in the Hydrogenated Grease (HVO) plant, which will have a production capability of 270,000 metric heaps annually.

It will transform waste products, such as utilized cooking oils, into renewable biodiesel and biojet fuel, likewise referred to as sustainable aviation fuel (SAF), utilizing green hydrogen produced by an electrolyser powered by wind or solar power.

Galp stated in a statement it got on Wednesday the three reactors to biofuels, which will permit the HVO system to "produce SAF and biodiesel in 2026 ... putting Galp at the forefront of establishing low-carbon services important for the energy shift".

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-