I have used the actual solar energy production data discussed in my post Statistical Analysis of Solar Energy Production in Adelaide to compare prices that were actually paid to Simply Energy over the three years, and what would have been paid had we been paying current Simply Energy prices without batteries, current AGL prices without batteries, and current AGL prices with 11.6 kWh of batteries with a maximum useable capacity of 9.9kWh, over that same period. I used our Simply Energy quarterly bills for the three years and the daily solar data via Bluetooth from our SMA 5000TL-21 inverter to derive daily figures for total solar energy generated, solar energy used in-house, solar energy exported, peak energy imported and controlled load (off peak) energy imported. I also did some costs and savings projections based on the actual consumption figures, investigating possible future increases in feed-in tariffs, peak tariffs and controlled load tariffs.
The tabular data in this analysis cannot be reproduced on this blog, so I have provided a link to a full landscape pdf of the document. I strongly urge you to read it if you are wondering whether the economics of the VPP make it worth joining.