Some customers are into solar to save the environment. Some customers are into solar to save money. And most of my customers are trying to do a bit of both.
When it comes to analysing the financial savings from solar there's a couple bits to remember.
Your cost of energy is a combination of 3 things
1) Your use of energy - imported from the grid
2) Your use of energy - supplied by your solar system
3) Your sale of energy - excess energy from your solar system which, because you don't use it, gets exported or sold to the grid
Now, the Feed-In Tariff (or FiT) only affects no. 3.
However the same guy that's offering you a good FiT is also the same guy that's selling you the electricity you use in no. 1.
Which means you need to consider both 1) and 3) when deciding on which electricity retailer (that's the AGL, Origin, Energy Australia, etc of the world) to use.
Typically customers will find that the amount of energy they sell (no. 3) is far less than the energy they import (no. 1) from the grid.
Now, if the electricity retailers were so nice as to all charge the same rate for 1) then all you'd have to do is pick the highest FiT to maximise your sale of energy for 3).
However the electricity retailers are too smart to do that. You'd find that those offering a high rate for 3) tend to also charge a bit more for 1).
So if a company is paying you 20 cents / kWh for FiT but charges you 5 cents / kWh more for 1), then because the amount of energy for 1) is higher than 3), you'll end up losing out in the end.
Luckily there are a couple of website that try or purport to help you. I'm merely pointing out that they exist. How useful they are to you, that depends on your own circumstances.
- CanStar Blue - Victoria Solar Feed-In Tariffs https://www.canstarblue.com.au/solar-power/solar-feed-in-tariffs-vic/
- Wattever - Best Solar Feed-in Tariffs by State and Territory https://wattever.com.au/retailer-solar-feed-in-tariffs-by-state-and-territory/
- Solar Choice - Which electricity retailer is giving the best solar feed-in tariff? https://www.solarchoice.net.au/blog/which-electricity-retailer-is-giving-the-best-solar-feed-in-tariff/