Last spring, a worker installing pipes in the roof of a Tesla Motors shop in Fremont, Calif., slipped and fell three stories onto a concrete floor. He broke both legs, and was concussed so badly that he drifted in and out of consciousness in a San Jose hospital for days.

In the hospital, the worker, Gregor Lesnik, asked for a lawyer. He was part of a crew of about 140 workers who had been brought over on a temporary B1 visa from Eastern Europe by a Slovenian construction company. According to Lesnik, he was paid less than $5 an hour — half the current California minimum wage, and a fraction of the going rate of $52 an hour for similar work in the area. The crew worked 10-hour shifts, six or seven days a week, with no overtime pay.

Lesnik’s accident was a reminder of a very old problem — just because a job is better for the environment, doesn’t make it better for the person who has it. Without strong labor standards, new green jobs can be just as dangerous and exploitative as the old ones they’re meant to replace. Treating workers poorly also risks the political goodwill that has brought the industry so many subsidies and tax breaks over the years.