That's probably true, if you don't want to count your influence on the carbon footprints of other people when calculating your "greenness". You should probably count it though.

So then, the very greenest things you can do probably involve mass murder and industrial sabotage.

Further down the list, after those, you have leading an ascetic life of minimal consumption and minimal travel while devoting yourself to the right sort of political advocacy.

A bit further down is dying underground as soon as possible. But it's important to note that a small amount of advocacy, sabotage, or murder per year can make it a net positive for you to continue living.

Way below all that stuff that nobody wants to do (and who can blame them) are (a) living as a hermit in the woods eating only berries and mushrooms or (b) living a normal life with a normal career and making consumer choices like buying solar panels and electric cars when other people might buy various combustion machines.

If you're not counting your effect on other people, (a) is a clear winner. However, people's consumer choices do have an effect on the direction of the economy. And, if you take those effects into account, I honestly don't know how to decide whether (a) or (b) appears higher in the greenness ranking.

I commented because of the claim from the article that this "personal power plant" was green. The people that read that shouldn't be misinformed, it could cause them to make choices that are counterproductive if being (relatively) green is their goal.