Smart Meters and Net Metering?

**Volusiano** · 11-24-2013, 07:14 PM

I don't have insight to what these readings mean. But I just want to comment that I think the only way you can know for sure what you're producing vs what you're consuming is if you have 2 separate meters, one for the solar production only, and one as the net (final) meter. It sounds like you only have the later (net) meter. So you're not going to be able to know what your actual solar production is.

In my case, my utility company put in 2 meters (one for solar only and 1 for net). Then on their monthly bill, they show the readings of both meters and everything is computed from there. But the billing is still based on the net meter only.

If you're interested to know what your actual solar production is and your utility company doesn't provide you with a solar only meter, you can put in your own meter to monitor this if you want. It can be an inverter monitor option offered by the inverter manufacturer. Or if you have microinverters, the monitoring that may come with it. Or you can go with a third party option like the TED 5000C or something like that where you couple the current transformers to the solar wiring that comes into your circuit panel and transmit that data to a receiving device.

**dmacioce** · 11-24-2013, 07:21 PM

Thanks for the response. I do have a revenue grade meter that measures my solar power generation. However, it is not something that SCE looks at. I am really just interested in making sure that SCE isn't ripping me off by underreporting the amount of energy they buy back from me. I thought I would be able to do this by comparing my own meter with theirs.

**Volusiano** · 11-24-2013, 08:46 PM

Originally posted by dmacioce

Thanks for the response. I do have a revenue grade meter that measures my solar power generation. However, it is not something that SCE looks at. I am really just interested in making sure that SCE isn't ripping me off by underreporting the amount of energy they buy back from me. I thought I would be able to do this by comparing my own meter with theirs.

I don't think their net meter is going to have solar generation numbers shown because their meter is not placed at the solar generation point. At its placement, it can only give you the net measurement between the solar generation and the load demand combined. So you can't just compare your own solar meter with their net meter and conclude that you're not getting ripped off.

If you don't trust the accuracy of their net meter, then you need to come up with an independent way to measure your actual load demand and combine it with your solar meter measurement to calculate what the net result is. Then verify your calculated net against the utility's measured net.

One way to independently measure your actual load demand is maybe to buy a TED 5000C device and hook up the current transformers against the load line and measure the cumulative consumption energy drawn on the load line.

**dmacioce** · 11-24-2013, 09:25 PM

Originally posted by Volusiano

I don't think their net meter is going to have solar generation numbers shown because their meter is not placed at the solar generation point. At its placement, it can only give you the net measurement between the solar generation and the load demand combined. So you can't just compare your own solar meter with their net meter and conclude that you're not getting ripped off.

If you don't trust the accuracy of their net meter, then you need to come up with an independent way to measure your actual load demand and combine it with your solar meter measurement to calculate what the net result is. Then verify your calculated net against the utility's measured net.

One way to independently measure your actual load demand is maybe to buy a TED 5000C device and hook up the current transformers against the load line and measure the cumulative consumption energy drawn on the load line.

Yeah, I understand that they won't be able to tell me how much I generate, but I did expect that the meter would be able to tell me the net measurement (consumption - generation) of my energy usage. As I described in the OP, the meter that SCE installed is not providing me with a net measurement of the usage, but only tells me (1) how much I have pulled from the grid in kWh (counter goes only in one direction: UP), and (2) how much energy is currently being pushed back onto the grid in kW. Their meter is not telling me the net measurement, nor is it telling me the total (in kWh) that has been pushed back on to the grid. I'd be perfectly happy to know on any given day, what my net energy usage is according to the SCE meter, but as it is, their meter does not provide that information, nor does it provide sufficient information for me to be able to calculate it myself using their data.

I'm sorry if I was not clear in my earlier posts, but this is what I want to do. Analogously, with my old meter, and before having solar, I could look at my meter each month, and then I could compare that with what is shown on my bill. In the past, I have caught several discrepancies between the amount billed, and what is displayed on the meter. In the past, I have been able to work with SCE to apply the appropriate credits on my bills in order to compensate for meter-read errors. So, basically, I just want to be able to look at their meter and determine whether I am being billed correctly.

The 35 kWh that are recorded currently on the meter are kWh that were used in nighttime hours when I am not generating electricity. I know for a fact that I am currently generating a NET SURPLUS of electricity, so I was expecting to see something on SCE's meter that would either be a net negative value or value that when added to the 35 kWh would result in a negative number, but I don't see that on the meter.

I assume that the meter is recording the things that I would like to see, but it is perhaps just not exposed on the display of the meter. According to the specs of the meter that SCE installed, it does store data for 90 days, and it does track net usage.

I have ballpark estimates of my usage, and those in combination with the figures from my solar power meter, I should be able to determine whether things are adding up correctly, but I would prefer not to wait 30 days until the bill comes to figure out that something is not right.

**Ian S** · 11-24-2013, 09:52 PM

One thing you could do is keep track of the readings on the meter every morning around the date that the meter is read and try to match up those readings with what's on your bill. I'm surprised your solar installer didn't give you the info on how to interpret your meter readings. Maybe the utility can do so.

**Volusiano** · 11-24-2013, 10:29 PM

Have you tried going online to SCE and see what kind of information they have about how to read the smart meters? I tried briefly and saw them post some short info on how to read the smart meters for NEM customers on the FAQ (with the 001 and 071 codes, etc).

My utility company provides online information on how to read our smart meters, and even displays day-by-day charts showing our on-peak and off-peak consumption. After our solar turn-on date, we can start to see the net on-peak and off peak consumption going negative on days that we over produce.

**bcroe** · 11-25-2013, 02:12 AM

2 Meters

Originally posted by Volusiano

In my case, my utility company put in 2 meters (one for solar only and 1 for net). Then on their monthly bill, they show the readings of both meters and everything is computed from there. But the billing is still based on the net meter only.

A grid tie billing system is built around the net meter. But I don't understand why the utility would
need a meter to measure solar output. How does that figure into the billing?

I know my solar production, because the inverters keep a running record. Bruce Roe

**Volusiano** · 11-25-2013, 03:30 AM

Originally posted by bcroe

A grid tie billing system is built around the net meter. But I don't understand why the utility would
need a meter to measure solar output. How does that figure into the billing?

I know my solar production, because the inverters keep a running record. Bruce Roe

I don't know why the utility would "need" a solar meter either, because all they really need to go by is the net meter and that should be good enough for billing purposes (and that's all they use for billing purposes). But they do provide the 2nd meter to measure solar generation, nevertheless. But it doesn't look like they use that meter for billing. If anybody cares to guess why this solar generation meter is useful to the utility company, I'm all ears. It seems like just a nice-to-have for them.

In my monthly bill, they do provide information on what the on-peak and off-peak on-site renewable generation values are (from the solar meter presumably). I know you can get solar generation information from your inverter, too. But it cannot differentiate generation between different time-of-use periods. The utility's solar generation meter can.

**inetdog** · 11-25-2013, 03:48 AM

Originally posted by Volusiano

I don't know why the utility would "need" a solar meter either, because all they really need to go by is the net meter and that should be good enough for billing purposes (and that's all they use for billing purposes). But they do provide the 2nd meter to measure solar generation, nevertheless. But it doesn't look like they use that meter for billing. If anybody cares to guess why this solar generation meter is useful to the utility company, I'm all ears. It seems like just a nice-to-have for them.

In those states which provide for a production credit (SRECs) as part of an incentive system, the POCO may be given the task of annually reading the production meter and reporting the results to the state.
In the case of either a lease or a power purchase agreement, a third party other than the utility may furnish or require a production meter. The installation at the house I purchased had a production meter in addition to the running production total kept by the SMA Sunny Boy GTI, but nobody ever reads it but me.

**Ian S** · 11-25-2013, 12:19 PM

Originally posted by inetdog

In those states which provide for a production credit (SRECs) as part of an incentive system, the POCO may be given the task of annually reading the production meter and reporting the results to the state.
In the case of either a lease or a power purchase agreement, a third party other than the utility may furnish or require a production meter. The installation at the house I purchased had a production meter in addition to the running production total kept by the SMA Sunny Boy GTI, but nobody ever reads it but me.

Yes, I believe the solar production meter is for SREC's. Part of the deal with APS was that they would receive the SREC's associated with my system. The solar installers put in a mechanical meter for the monitoring of the solar production. A few months later, APS swapped that meter out for a smart meter that presumably transmits the data back to them without having someone go out and read it.

**bcroe** · 11-25-2013, 12:45 PM

Originally posted by Ian S

Yes, I believe the solar production meter is for SREC's. Part of the deal with APS was that they would receive the SREC's associated with my system. The solar installers put in a mechanical meter for the monitoring of the solar production. A few months later, APS swapped that meter out for a smart meter that presumably transmits the data back to them without having someone go out and read it.

OK, SREC's. Apparently not done in NW ILL. Here, such a meter would need to be placed on a building
450' back and not visible, with no road access. Far away from my net meter. But maybe that wouldn't
matter, the net meter seems to be read by a cell radio. Currently getting light snow and 2 KW, guess
that is good. Bruce Roe

**SunEagle** · 11-25-2013, 01:31 PM

Originally posted by bcroe

OK, SREC's. Apparently not done in NW ILL. Here, such a meter would need to be placed on a building
450' back and not visible, with no road access. Far away from my net meter. But maybe that wouldn't
matter, the net meter seems to be read by a cell radio. Currently getting light snow and 2 KW, guess
that is good. Bruce Roe

Did you raise your panels to the upright "snow" condition?

**bcroe** · 11-25-2013, 03:03 PM

Originally posted by SunEagle

Did you raise your panels to the upright "snow" condition?

Been busy with other winter prep, the "panel platform lifter" is still in the design stage. Looking
at the snow on the low angle surface, I'm sure raising them would clear them faster & increase
power. Power is holding at 2 KW, but I have some panels near vertical, nearly clear. My clamp
on ammeter says those are doing about 3 times the output per string of those with snow cover.

This pic pretty much shows the snow advantage of near vertical angle. When the sun comes back,
I expect the snow to slide off the lower angle panels, but meantime I lost much of their days'
production. Learning more as I go... Bruce Roe

Attached Files

NS1snow.jpg (354.5 KB, 14 views)

**Volusiano** · 11-25-2013, 03:24 PM

^^^ It seems like it shouldn't be too big of a deal to manually brush the snow off the panels since they're at ground level, no?

Smart Meters and Net Metering?

Smart Meters and Net Metering?

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