LISBON, Dec 19 (Reuters) - Portugal's Galp Energia expects to begin 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 manufacturer and refiner, stated 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 loads each year.

It will change waste materials, such as used cooking oils, into and biojet fuel, also known as sustainable aviation fuel (SAF), using green hydrogen produced by an electrolyser powered by wind or solar power.

Galp said in a statement it received on Wednesday the 3 reactors to process biofuels, which will allow the HVO system to "produce SAF and biodiesel in 2026 ... placing Galp at the leading edge of developing low-carbon solutions necessary for the energy transition".

Galp is likewise 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-