グレー水すい素そグレーすいそじ字FuriganaMeanings1noungray hydrogen; grey hydrogenTechnical term in energy and environmental contexts; hydrogen produced from fossil fuels (typically natural gas) with CO₂ emissions, as opposed to green or blue hydrogen.グレー水すい素そは製せい造ぞう時じに二に酸さん化か炭たん素そを排はい出しゅつする。