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

In 2015 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 heaps per year.

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

Galp stated in a statement it received on Wednesday the 3 reactors to process biofuels, which will allow the HVO unit to "produce SAF and biodiesel in 2026 ... placing Galp at the forefront of developing low-carbon options essential for the energy shift".

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