First Month Production Doesn't Match Electric Bill

[Ward L]

I suppose it is too much to ask, but my Enphase system monitor says my panels produced 1,810 kWh but my SoCal Edison electric bill says I only produced 1,384 kWh. I would expect it to match up closer than 25%. What am I missing? My bill shows my Consumption and Net Generation. What kind of accuracy have others found with the Enphase Envoy system? Wonder what I should expect for accuracy?

[slopoke]

I suppose it is too much to ask, but my Enphase system monitor says my panels produced 1,810 kWh but my SoCal Edison electric bill says I only produced 1,384 kWh. I would expect it to match up closer than 25%. What am I missing? My bill shows my Consumption and Net Generation. What kind of accuracy have others found with the Enphase Envoy system? Wonder what I should expect for accuracy?

Is your bill and the enphase numbers for the same time period? Also did your installer turn on your system before getting the go ahead from the utility? If the installer turned it on prior to the ok, all of the production prior to the ok won't count.

[Ian S]

I suppose it is too much to ask, but my Enphase system monitor says my panels produced 1,810 kWh but my SoCal Edison electric bill says I only produced 1,384 kWh. I would expect it to match up closer than 25%. What am I missing? My bill shows my Consumption and Net Generation. What kind of accuracy have others found with the Enphase Envoy system? Wonder what I should expect for accuracy?

Maybe the key is in the phrase "Net Generation." My APS bill shows only the amount of solar production that is sent to the grid. My total production is typically far more.

[HX_Guy]

Yeah, I remember reading a thread on here or another forum that the electric company only sees the net production, as in, what' sent to them. Your house will actually use up some of the energy as it's being produced so the electric company never sees it.

[Ward L]

Consumption - Net Production = Total Electricty Used this Month

The numbers are the same date consistent with the bill. There was a little power production to test the system, but it was minimal and doesn't explain the difference. The bill shows Consumption and reflects a number that I would expect for my monthly consumption of kWh. I agree the Net Generation could and should be the export to the grid since I made more electricity than I used. But Edison shows on my bill: Consumption - Net Generation = Total electricity usage this month in kWh.

[silversaver]

SCE will only show your net production after consumption during solar production + your consumption. At end of billing, it shows either + or - net credit.

For example: -730kWh is the credit I have with SCE, but that doesn't mean my solar only produce 730kWh. There is no way SCE will know what is your solar production for the month.

[Ian S]

The numbers are the same date consistent with the bill. There was a little power production to test the system, but it was minimal and doesn't explain the difference. The bill shows Consumption and reflects a number that I would expect for my monthly consumption of kWh. I agree the Net Generation could and should be the export to the grid since I made more electricity than I used. But Edison shows on my bill: Consumption - Net Generation = Total electricity usage this month in kWh.

I think the problem is in their reference to "Total Electricity Usage." They should have called it something else as an ordinary mortal would think it referred to all the electricity one used both from their own production and from the grid. What I think they really mean is total billable electricity i.e. what you took from the grid less what you sent to the grid.

[J.P.M.]

I suppose it is too much to ask, but my Enphase system monitor says my panels produced 1,810 kWh but my SoCal Edison electric bill says I only produced 1,384 kWh. I would expect it to match up closer than 25%. What am I missing? My bill shows my Consumption and Net Generation. What kind of accuracy have others found with the Enphase Envoy system? Wonder what I should expect for accuracy?

It could be a problem with the Enphase monitoring, and that's worth checking out. But, before I called the installer, I'd be more inclined to think the discrepancy lies in differences in dates and periods between the POCO billing and rate structure, and the Enphase monitoring dates. I'd start there and see what gives. As I suggested in a prior post, welcome to POCO rate hell.

[Ward L]

Like I said...

I've done the comparison for the same dates as shown on my June power bill. Take a look at the first page of your June SCE bill. I believe they have recently changed their bill format slightly. Right under the amount you owe: "Compare the electricity you are using" It says Consumption. I believe this to be my home electricity consumption for the billing period.... It seems about what I would expect.

[Wy_White_Wolf]

Ian S has the right answer in post 3.

Net generation as reported by the PoCo and Total production as shown by Enphase are not the same thing. Net generation only shows what you sent to the grid. The 25% difference is what you used straight from the system so it didn't get sent back to the grid.

Conversely, consumption as reported by the PoCo does not include what you used directly from the system. Only what you consumed from the grid. If you add that 25% difference to the comsumption figure you will get the total you used during the time period.

WWW

[russ]

Conversely, consumption as reported by the PoCo does not include what you used directly from the system. Only what you consumed from the grid. If you add that 25% difference to the comsumption figure you will get the total you used during the time period.

WWW

Right - No way for the POCO to know what one uses internally - doesn't pass through their meter.

[Ian S]

Right - No way for the POCO to know what one uses internally - doesn't pass through their meter.

Generally that's true. However, for those of us who have separate utility grade production meters, the POCO could get that info. When my system was installed, the installer put in a mechanical meter to track my production. Within a few months, the POCO swapped it out for a smart meter that I assume has the capability of being read remotely. Not sure why the POCO would go to the trouble if they weren't interested in my production.

[russ]

Generally that's true. However, for those of us who have separate utility grade production meters, the POCO could get that info. When my system was installed, the installer put in a mechanical meter to track my production. Within a few months, the POCO swapped it out for a smart meter that I assume has the capability of being read remotely. Not sure why the POCO would go to the trouble if they weren't interested in my production.

If the cables from the PV system pass through a meter then OK but if they don't then no way.

[gregvet]

Not sure why the POCO would go to the trouble if they weren't interested in my production.

Our POCO placed a smart meter on our PV system. It has something to do with a mandate requiring our POCO to obtain a certain percentage of power from renewable resources by a certain date (percentage/date I am not sure of). They count all of the GT installations from wind turbine/solar PV as part of this in addition to purchasing power from renewable resources.

[Ian S]

Our POCO placed a smart meter on our PV system. It has something to do with a mandate requiring our POCO to obtain a certain percentage of power from renewable resources by a certain date (percentage/date I am not sure of). They count all of the GT installations from wind turbine/solar PV as part of this in addition to purchasing power from renewable resources.

I think that's the same here in AZ.