I was never impressed with PowerShop. First, whenever I ran their tariffs through my historical usage spreadsheet (I have a quarter of a million rows of 5-minute data) they came in the bottom half of the pack cost-wise for my usage patterns.
But what irritated me most is the way that, when I last looked at them in detail in 2019, they weren’t super clear that they only carbon-offset their electricity purchases from the generators (which included coal and gas-fired gens). They were not 100% GreenPower suppliers by default. If you wanted 100% GreenPower, you had to pay a kWh surcharge, like with all other retailers - and their surcharge was actually higher than that offered by the big retailers.
People might have assumed they were buying 100% GreenPower from PowerShop when they were merely buying carbon-offset dirty power.
Carbon-offsetting should be the last resort when there is no other way to abate emissions. That is not the case with electricity generation, since zero-emission generation options exist.
To me, buying 100% GreenPower is an order of magnitude more important than the retailer you buy it from. I buy mine from Origin because they offer the best deal for my usage pattern, even though according to GreenPeace, Origin is something approximating the devil reincarnate.