Gross generation meter Q

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romex jockey

Senior Member
Location
Vermont
Occupation
electrician
fellas, is there some sort of gross generation meter, something made by a manufacturer (Milbank, etc) dedicated to accepting a gross meter sitting next to a net meter.....?

~RJ~
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
fellas, is there some sort of gross generation meter, something made by a manufacturer (Milbank, etc) dedicated to accepting a gross meter sitting next to a net meter.....?

~RJ~
Not exactly sure what your asking...
As in utility style meter or recording style meter?
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
Also not quite sure what you're asking, or why.

If you need a socket for a generation meter on the load side of the utility meter just install a standard meter socket in the circuit. I have never seen such a thing pre-configured nor can I imagine there'd be a market to justify it over existing standard components.
 

romex jockey

Senior Member
Location
Vermont
Occupation
electrician
Also not quite sure what you're asking, or why.

I'm usually parking a milbank meter/main next to the net meter, nipple on it.

It's just a normal meter/main 100A

I'm asking if any metering company manufactures something exclusive? Or maybe i should be asking what you folks do?

~RJ~
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
I'm usually parking a milbank meter/main next to the net meter, nipple on it.

It's just a normal meter/main 100A

I'm asking if any metering company manufactures something exclusive? Or maybe i should be asking what you folks do?

~RJ~
I think I’ve got it..

the old style mechanical meters would register kWh forward with the numbers incrementing up when the power was flowing to the customer. When power was being exported to the utility they would register backwards and the numbers would decrement. This amounted to a true “net metering”

electronic meters have many advantages. You can set them up with all kinds of programs. We actually lock ours in secure forward. This means no matter which way the power flows the numbers always register forward. We can see there has been some reverse flow, but the customer will always be charged for forward power. Don’t tie to our system without our knowledge.. “totalizing meter”

then we get into something like the kV2c. A meter that has all kinds of functionality. It will register forward, backwards, give phasor magnitude and angles,net, and gross meter if that’s what you want. (kWD,kWCum, etc)

we have started a program where we are paying a premium for all power exported during our peak times. For this we use something like a TOU meter that keeps up with time.

Our old metering setup was a two meter policy where everything produced went through one meter at our buy rate, then the consumption went through a second meter that charged the retail rate.
inly problem with this is it didn’t allow you to use what you produced.
 

winnie

Senior Member
Location
Springfield, MA, USA
Occupation
Electric motor research
electronic meters have many advantages. You can set them up with all kinds of programs. We actually lock ours in secure forward. This means no matter which way the power flows the numbers always register forward. We can see there has been some reverse flow, but the customer will always be charged for forward power. Don’t tie to our system without our knowledge.. “totalizing meter”

Does this mean that the meter doesn't run in reverse, or does it mean that the meter runs forward even when power is flowing in reverse? Meaning that you add PV, export power, and then _pay_ full retail price for the exported power? Well, as you say, don't tie into your system without your knowledge, so I can't really say this is unfair.

But if the meter charges for total power flow no matter which direction, what happens with displacement power factor when energy is shuttling back and forth twice a cycle?

-Jon
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
Does this mean that the meter doesn't run in reverse, or does it mean that the meter runs forward even when power is flowing in reverse? Meaning that you add PV, export power, and then _pay_ full retail price for the exported power? Well, as you say, don't tie into your system without your knowledge, so I can't really say this is unfair.

But if the meter charges for total power flow no matter which direction, what happens with displacement power factor when energy is shuttling back and forth twice a cycle?


-Jon

Yes.

what I meant is the meter reads forward (delivered power, 0 degrees, +) usage, and reverse “usage” or export power (received power, 180 degrees, -)

Think CT if polarity is switched.
 

Carultch

Senior Member
Location
Massachusetts
If you want to control the direction your meter will count the power it accumulates, plan accordingly for which way you wire the top and bottom terminals of the socket. The meter globe is built for power to flow down from the top terminals from the utility, and out the bottom terminals to the load. Overhead rated sockets only have enough room for top-down wiring, and typically have a built-in hub or hub provision on the top for the service mast. Underground-rated sockets, have enough extra space to U-turn the wires inside. Dual-rated OH/UG sockets are just like UG rated sockets, except with the additional provision to attach a conduit hub on the top.

A customer-owned production meter that uses a utility-style meter socket, is typically wired in a manner, to count production as positive. Any meter whose purpose doesn't concern the utility, or whose purpose doesn't concern program with a policy that requires otherwise, is usually wired this way. Such as a Locus data logging production meter, that is built for utility meter socket housing. It is wired so the most common power flow direction, will cause it to count positive.

Depending on the application of this meter, there may be a specific reason why you would have to arrange your meter wiring the other way around. For instance, you may have an incentive program that requires such a meter, and that program may have a standard for it to be wired in the same orientation as a utility service meter. This way, power drawn from the utility, is assigned a positive sign, consistent with the utility's standards. Such a production meter, would count to the negative by design.
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
does it mean that the meter runs forward even when power is flowing in reverse? Meaning that you add PV, export power, and then _pay_ full retail price for the exported power?

-Jon

we have actually had people come into the office to complain because their bill went UP after installing PV behind the utility meter and export power.

Without an interconnect agreement and our approval, along with required anti-island testing...
That’s a no-no.

This is the easiest way to find them we have found yet..
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
we have actually had people come into the office to complain because their bill went UP after installing PV behind the utility meter and export power.

Without an interconnect agreement and our approval, along with required anti-island testing...
That’s a no-no.

This is the easiest way to find them we have found yet..

OMG :LOL:
 

Flicker Index

Senior Member
Location
Pac NW
Occupation
Lights
If you want true production metering for tracking purposes, you'd need to slip in CTs n between the photovoltaic static converter and everything else.
Why? If the alternative energy setup is producing 1kW and the premise is using 1.5kW and this goes on for an hour, any other meter would register 500Wh importing.

EKM meters for example are made to report the sum of all power going through the meter, and a separate value for exported power. I don't know what you would use the sum of import + export for though. It reports the import+export, and export value.
To get import kWh, you take the total kWh and subtract export kWh.
To get net kWh, you deduct export kWh again.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
It is not uncommon for third parties to require an independent production meter that uses a standard base meter and socket. (In other words, it doesn't have to be a meter that uses separate CT components.) And yes, the socket would go between the inverter output and everything else.
 
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