Sir John Acton once said "Power tends to corrupt. Absolute power corrupts absolutely".
Unison increasing its line charges to clients who self generate is nothing more than abuse of monopoly power. The excuse that it wants to be fair to those who don't self generate lacks any credibility whatsoever.
For starters power users that have chosen to reduce the power bill through self generation have paid out thousands of dollars for the self generation equipment and installation. This is not taken into consideration in terms of alleged fairness.
Secondly Unison does not supply power, only the lines that carry the power for the power provider; in my case Trustpower. For that service, it charges a fixed line fee (showing on the power account) regardless of the power the consumer uses. So my power savings relate to my Trustpower account only and have nothing to do with Unison. Its line costs have not altered at all despite the significant drop in power consumption from the grid.
Here is an analogy to illustrate the lack of credibility in Unison's reasoning;