Consider the following heavy industries: 1. Fertilizer plants 2. Oil refineries 3. Steel plants. Green hydrogen is expected to play a significant role in decarbonizing how many of the above industries?

1. Fertilizer plants — Correct. Ammonia/urea production uses hydrogen as a feedstock; green hydrogen can replace grey hydrogen made from natural gas, cutting emissions.

2. Oil refineries — Correct. Refineries use hydrogen in hydrocracking and desulfurization; green hydrogen can decarbonize these processes.

3. Steel plants — Correct. In steelmaking, hydrogen can act as a reducing agent in place of coking coal, especially in direct reduced iron (DRI) routes.

Hence, all three industries can be significantly decarbonized using green hydrogen.