Edit: since people are asking for examples, I would have to point to the insane cost of training modern ML models. For instance, according to [1], training a single big NLP model can burn up to 620,000 lbs of CO2.
I say a lot of energy consumption is hidden because it's generally moved to data centres, which by the way use up astronomical amounts of energy [2]
[1] https://arxiv.org/abs/1906.02243
[2] https://ec.europa.eu/jrc/en/publication/trends-data-centre-e...