Following several calls to AGL no-one can tell me the exact method used to calculate the net position on my solar installation costs. Loads fluctuate minute by minute, the tech support team tell me a smart meter has 30 minute updates here on the community blog it is reported as every 15 minutes. The bill analysis and bill overview in the AGL app both give different results which is in itself confusing. So does AGL calculate the net energy position based on the integral of all samples taken over an hour, day, week or the entire billing period. Depending on the formulae used you end up with vastly different costs. The energy used from the grid and the feed in tariff are based on different rates, and because of this I can end up with an overall period charge that can vary by as much as 3 to 1 depending on the method used to calculate the net position. Origin energy were also unable to give me an answer to the same question. Further if you record the daily usage of a customer, to work out a usage pattern if you skew the smart meter sample times i.e. not necessarily at the top or bottom of the hour, you can change the net position to optimise the billing charge in favour of AGL. I would just like to know the answer.
Thank you for your post!
The solar content shown on the online account and bills are a total of only what is put back into the grid. Digital (Smart Meters) provides 15 minute consumption data and you can find more information on these meters here. You can view and track how much energy you usage via your My Account online or the AGL app.
The rate we pay you is the feed-in tariff which is different to the rate we bill per kwh which is the energy price in which you use.
This does not answer my question "how does AGL actually calculate the net position and charges?" (what is the formula used to cost the bill)
How the calculation is made determines the cost. This cost can vary say from $1000 a quarter to $3000 per quarter depending on how you make the calculation. It's not a simple matter of adding up all power generated less that supplied, and paying the difference, or being paid the difference at the feed in rate, for a 91 day period. This would be what most people would expect but that's not what my bill says. In our case after solar installation our bill has increased not decreased as you would expect.
The calculation of an AGL bill is shown on the page where it has "How we've worked out your bill"
Information of kwh usage is provided by the meter coordinator Active Stream. If you have solar, there would be 2 registers, one for usage and the other for the solar input that's not used and put back into the grid.
We take this information and multiply this by our current price per kwh. The daily metering supply charge is also calculated and applied to the bill.
The Standard Feed-in Tariff is the solar total kwh that's fed back into the grid.
I found the problem, we have a 3 phase inverter, 3 phase air-conditioner, and the remainder of the house is wired to L2 (phase-2), mostly L2 shows we are importing around 2.2 amps as a background usage while L1 and L3 are exporting around 3.9amps each during the day. As such both the 03 and the 13 registers are continuing to increment at the same time as we are using energy from L2 but putting back twice this with L1 and L3. Should not the smart meter be smart enough to work out the real time position is that we should be in credit not debit during the day. One would think the smart meter would add up L1+L2+L3 then subtract usage and then bill us in that manner. One would think you can't consume and export at the same time but our atlas MK 10D somehow does. An explanation would be great