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Grid Sell and Electric Meter

Posted: Sun Apr 07, 2019 10:57 am
by Yoe
Do you need a special meter in order to "sell back" to the grid?

What would happen if someone enabled it before full utility approval for testing purposes?

Re: Grid Sell and Electric Meter

Posted: Sun Apr 07, 2019 4:33 pm
by Mike Curran
For my initial grid-tied system of 1,440 watts capacity (2007), I got a permit from my utility but (I'm assuming) because my output to the grid was so low, they never changed out my original meter, until I added 6,450 watts in 2012. Still, with the old meter I could observe the disk that turns as you're using grid power and on sunny days it would slow or even start to turn "backwards".

However, I have heard that some non-net meters may not account for your grid feedback at all and may even erroneously show your feedback as use, charging you for energy you've fed to the grid. For testing purposes probably not a problem but best to get the permit, and if your system is large enough, a new, net meter. Without it you really can't accurately account for what you're selling to the grid.

Re: Grid Sell and Electric Meter

Posted: Mon Apr 08, 2019 1:02 pm
by gregorio
When my 10kW system was getting inspected for approval in 2015, I left it on after it passed inspection. However, my utility company (PGE) did not credit me for any power I sent to the grid until they got all paperwork in order. That took about 3 weeks. My meter was already net metering capable because it was not changed.

Re: Grid Sell and Electric Meter

Posted: Wed Apr 10, 2019 4:48 am
by jbakker
On my system I have played with a couple of grid tie cards.
I have one of the so called smart meters. Now when using from the Grid there is a little arrow that scrolls from left to right facing the meter.
When I was feeding the grid back the arrow from right to left and there was an exclamation symbol on the display as well, so I was feeding the grid.
The question is was can the utility company sense this? I have no agreement to feed back as the town has no interest in net metering.

Re: Grid Sell and Electric Meter

Posted: Wed Apr 10, 2019 5:48 am
by mexsudo
Last month when my grid connection was first made we stepped out to the meter, it was indeed spinning backwards.
it was a 20 year old conventional meter.
I recorded the readings and it was counting down at a rate that made sense, and again ran normally when the sun was not out.
This would raise huge red flags with CFE (our federal electric agency) if the meter reader saw it turning backwards, or it was noted in the office that my use went down radically (power theft).
Grid-tie is permissible, and encouraged here, but a contract is required.
They bank my power for one year, and I draw from it as needed, 1:1 ratio. I think that is cool.

After my installer had me connected he prepared the paperwork for the formal contract with CFE and submitted it for me.
A few days later the meter was replaced with a modern digital one that has an elaborate display that I don't quite understand, but it does have an arrow showing the direction of flow. It supposedly collects more data, has a wifi indicator. The meter reader said that wifi does not work, he will still return and read the meter as before.
I checked on line, the contract was approved. My next invioce should reflect the changes.

Re: Grid Sell and Electric Meter

Posted: Wed Apr 10, 2019 11:40 am
by Megunticook
Yoe wrote:Do you need a special meter in order to "sell back" to the grid?
My POCO, Central Maine Power, replaced my analog meter with a pair of analog meters--one "in" and one "out." When CMP pushed the smart meters on all their customers I opted out, which is why we got the double analog meters. From what I understand most modern smart meters can measure current flowing in either direction.
Yoe wrote:What would happen if someone enabled it before full utility approval for testing purposes?
That's not a good idea. You'd certainly be jeopardizing your interconnection agreement. From the POCO's perspective, they want to make sure your system is safe and won't backfeed during an outage and get someone hurt. In my case I it only took about 5-6 weeks to get the meters installed and get the green light to put our system online.

Re: Grid Sell and Electric Meter

Posted: Wed Apr 17, 2019 4:45 am
by AntonyH
Hi, My first post about my Outback power system. I have had a system working for about 5 years , using 12x 300w panels, 12x100ah batteries linked to supply 48 volts,
I have a Flexmax M80 inverter and a grid tie systwm to sell on line which has been working very well until the batteries over heated. I have changed to 4x200ah gel batteries as well as installing 6x 350volt extra panels. How do I change the settings to use these batteries and new panels?.
Control is thro a Mate3s
Hope you can help?

Re: Grid Sell and Electric Meter

Posted: Fri Nov 08, 2019 5:08 pm
by badwolf
So I have a real problem with this.

Inverter: GS 8048
Batteries: 860Kwh lead acid
CC: 2 Midnight Classic 150s
Solar: 24 275w panels

I am out in the Ozarks of Missouri and there is nobody that knows these grid interactive systems in the whole state.

I had about 7.5KW of panels installed in 2014, but it didn't get finished. I changed contractor in the middle because they didn't want to deal with the grid for issue, so I went with a guy who said he could finish it. He botched everything (years later I found out that he had wired one string backwards and it had been causing the breaker to trip in the junction box).

In any case, when it came time to get it approved, he told me that we needed to dig a separate line to the poll and sell back on that line. After many weeks of working with this system he had no idea how it worked!! So we got on the phone with the utility (CoMo electric, it's scoop). The utility said that anything that would spin the meter backwards was a no-go. Could never find a way to get them to approve it.

So for the past 3 years since I commissioned it, I have been running the system without an agreement in place and using battery backup mode only (no sell back). I have a 3 pile transfer on the shed so it just looks like I am switching back and forth to the grid manually.

In the mean time I have been using the HBX mode or "grid use time" to run batteries down to store the extra energy. I estimate that I have been using losing about 30 to 40 percent of the available production and have also been depleting the lead in the batteries. I have been tempted to sell back and run meter backwards instead of killing batteries and wasting energy but I don't want to push my luck since I don't have an agreement.

If anyone knows how to talk to utility company or could help me out then it would be highly appreciated.

Re: Grid Sell and Electric Meter

Posted: Fri Nov 08, 2019 5:23 pm
by Mike Curran
I couldn't find anything on CoMo's website re net metering. But according to this website https://renewmo.org/missouri-clean-ener ... ction-act/ net metering is legally required to be available to all residential utility customers in Missouri. There's a phone number on the site, I'd give them a call. Good luck!

Re: Grid Sell and Electric Meter

Posted: Sat Nov 09, 2019 4:03 pm
by badwolf
Mike Curran wrote:
Fri Nov 08, 2019 5:23 pm
I couldn't find anything on CoMo's website re net metering. But according to this website https://renewmo.org/missouri-clean-ener ... ction-act/ net metering is legally required to be available to all residential utility customers in Missouri. There's a phone number on the site, I'd give them a call. Good luck!
This is super helpful. Can you also point to a resource that defines net metering in such a way that energy is being bought and sold from the same L1,L2, and neutral and not separate for buy and sell?

Thanks!