Another major coal unit has tripped in Victoria, leaving the state without some 2,130MW of so-called “reliable” thermal power now offline, and increasing fears of a potential supply squeeze in the coming summer.

The latest failure came from the increasingly challenged Yallourn brown coal generator, which according to The Australia Institute lost two units in the last 24 hours, one for “scheduled” maintenance, and another an unexpected trip.

This, combined with the event that has taken a unit out at the Mortlake gas generator until Christmas at least, and a unit out at Loy Yang A for long term repair, and another off-line, means that 2,133MW of coal and gas capacity is currently out of action.

That includes two of four units at Loy Yang A, and two of four units at Yallourn. If repeated in the heat of summer, that will again cause problems for the market operator, which had to deal with a similar level of outages, some planned, mostly un-announced, in last summer’s record heatwave.

“So much for reliability in fossil fuel generation,” The Australia Institute noted in its tweet.