What does it mean, that the greens hold the balance of power in the senate?
The Greens don’t really hold the balance of power at the moment; they will in the new Senate that comes into effect next year. There are 76 seats in the Senate. The ALP currently hold 32, the Coalition have 37, there are 5 Greens, 1 Family First and one independent (Nick Xenophon). So the ALP and the Greens together only have 37. Family First will generally vote with the Coalition, so even with Xenophon on board the ALP wouldn’t actually get a majority. A tied vote in the Senate is resolved in the negative. To pass the ETS, the ALP needed either the Coalition or everyone else (not just the Greens) to support it. In the new Senate it looks like the ALP will have 31 seats, the Coalition will have 34, and the Greens will have 9. So the Greens voting with either major party would constitute a majority, hence they will have the balance of power when the new Senators take their seats in the middle of next year. These are still provisional results at this stage.