Is there no end to government avarice via tax? 
If you must tax, use it to disincentivise bad behaviours such as gambling.

Let people live their lives as free from intervention as possible. Using a free resource as the sun is a good thing.

Agree with Ricky T that this "Sun Tax" will be an unnecessary disincentive - albeit applied (if it proceeds) by the Energy Companies themselves (not the government).

Better to retain the incentives for roof-top solar and fix up the grid (which is problematic but possible) to fully utilise the excess electricity. This excess (exported energy) is generated by over 3million already installed roof-tops in Australia and will increase considerably while energy prices keep rising.