Recently moved to Amber Electric for their wholesale price. I know there is a risk that the price could spike. On the other hand, there is a protection that it won't be more than VDO over the year. I was previously with AGL, which was better than VDO.
Here is my take on Amber based on the last two months' usage.
The price spike is guaranteed around before and after school hours most days.
The price spike happens even in winter. Up to now, I had 3 spikes of over 1$ per KWH, which swallowed half of my savings for that month compared to my AGL rate.
Even after all these, I managed to get few $ savings over my AGL plan roughly per month.
So the dilemma is that even in winter I don't save much, what will happen in summer when it is guaranteed to spike. Anyone out there still sticking with Amber? or moved out of Amber? How much you save?
Anecdotally from my own take on Amber is it seems to be suited better for people who's electricity usage would be suited for the usual "Time of Use" (TOU) billing rather than flat rate (anytime, etc). This is due to the rate being much lower off-peak (middle of the day). i.e. work-from-/stay-at- home people.
If you can keep most of your power usage to during the day (when the rate is lowest) it could be well worth it.
Not sure on the trade-off with solar - you get a cheaper rate during the day, but that's when your generating the most power from your solar, so not only are you potentially not benefiting from the lower rate, your also not getting paid much for any power you're exporting.
Amber looks like a great concept, but without people timing their usage I'm not sure on the benefit to them.