Solar & Smart Meters

bart

We got our new Smart Meter a few months ago. But the monthly bills seem to be going higher. The bill shows both consumed and generated kWh. However, according to my TED5000, the consumed was fairly close (1007 vs 1055), but generated was -284 vs -667. I'm going to check again on the next bill in March to see if this consistent.

I'm wondering if anyone else has noticed this. Can I trust the smart meter and TED?

Thanks, Bart

BB.

Re: Solar & Smart Meters

Don't know... There have been enough issues with smart meters to know that errors are not impossible, but they are also pretty rare (I have also wondered if the complaints of "over charging" for may new digital meters was really the result of under billing by 20-40+ year old mechanical meters). When we got GT Solar ~8 years ago, the billing computer read our old mechanical meter running backwards as a "miss-read" by the meter reader--And added ~1,000 kWH to our (near zero kWH) bill.

It was common at the time for the first bills for GT systems to have some sort of errors in them with our utility.

I forget if it was here, or I read it somewhere else--The "high tech" method for verifying a meter's accuracy. Plug in an electric heater at the house for an hour or so and have the service tech see if the reading of the "known load" was correct.

Today, with digital meters that have different registers for different rates (Time of Use) and possibly logging power used vs power generated in different registers, it is pretty much impossible for a customer to verify the meter's functions.

In general, if the data difference between the TED and your meter is within 5%, then that is probably "A OK"... If the difference is 10% or more, then you may want to try a different power meter brand/model to see if they disagree with the TED/Utility or not.

-Bill

Dashadeaux

Re: Solar & Smart Meters

A neighbor complained his bills were also unexpectedly high after getting the new smart meter when his solar went online. A few months of the behaviour was enough. He call the power company and upon investigation it was determined the meter had been incorrectly programmed for his rate plan. After the power meter was reprogrammed, he's a happier person.

waynefromnscanada

Re: Solar & Smart Meters

I'm not grid-tie, but use extremely little from grid. Few days ago Nova Scotia Power came and changed my meter to a new digital one. No one else around here has had theirs changed. Spoke with the guy, he was very aware I was using very little power. That's why they changed it. Hahahaha We shall see how it works out. Still showing all zeros after 3 days.
Notice it's specs list it as ".5 to 200 amps". Wonder if .5 is the lowest it will read, or is it only accurate above .5 ?
If it only reads above .5 they'll probably be back to change it again.

Photowhit

Re: Solar & Smart Meters

They guys driving around in the trucks are all curious about my solar and a great asset, They even gave me 12 feet of #6 ground when I complained that the local source wanted to sell me 100' at 60 cents a foot. They even gave me a clamp to save me a trip to town. In general the Coop is managed by and outside group, so the "us against them" has the workers of the power company on the 'us' side. When my big forklift battery came, one group watched me use some landscape timbers as ramps and side it into my battery box. The next time out they had to stop and show the setup to a new worker. All in all, it's a very friendly relationship.

solar_dave

Re: Solar & Smart Meters

In general my TED is darn accurate, within about 1% of actual load tests and what the inverters report. Where I have question with the comparison is how the smart meter samples and accumulates the kWh and reports them. I think mine does so on a 15 minute frequency with some sort of averaging or smoothing while the TED does 2 second adds of the loads. All in all the TED lines up well with instantaneous generation and loads.

bart

Re: Solar & Smart Meters

What's interesting is that my consumption was nearly the same as the TED. SCE=1007 and TED=1055, only .048% difference. While Generation was way off. SCE=-284 TED=-667. Nearly .57% difference. I started logging with the Sunny Data Control today. At least I can compare TED's readings with the SMA7000. If it turns out TED is accurate, I might have a case with SCE. Now I wish I never allow the Smart Meter to be installed. I Google Smart Meters and found many people saying their bills went up! But none that I could find involved solar generation. I'm thinking it might be worth you check your bills and generation for a problem.

Bart

BB.

Re: Solar & Smart Meters

Your numbers are 4.8% and 57% error (move decimal point two places to the right for %). It sure sounds like there is a generation error. Does your digital meter say what the kWatt rate is? Many of the digital meters in our area have a two number display. The large one displays net power used/generated. And the small display cycles between line voltage (244 VAC or so) and the current power draw/generation in kWatts (1.300 would be 1.3 kW or 1,300 Watts).

You can look up the meter for an online manual... One meter, I could take a small magnet and have it cycle through the display and show a bunch of different values (power factor, phase to phase voltage, current, harmonics, etc.). You may also be able to read your 15 minute meter values through your utility's website.

-Bill

bart

Re: Solar & Smart Meters

Yep, you are right. Didn't move that decimal point I'll investigate the meter today.
So far in my testing comparing TED to SMA outputs, they are real close to each other. TED was about 30 Watts higher.
So, I'm thinking I can trust TED and its history. I guess next I show find all the billing since the Smart Meter was installed and compare generation.
Monday, call SCE and have them explain why the generation are low. Maybe request to go back to analog meter - I like to see the meter spin backwards again

Bart

bart

Re: Solar & Smart Meters

I think I found out what's happen. Putting TED in Multi-panel mode indicates a percentage of power generation is used by the house. Even though I'm generating say 5611 watts, the meter is only seeing the excess of 3610. The rest (2101 watts) stays in the house about. I guess I need to reduce my consumption even more

Thanks everyone, Bart

solarvic

Re: Solar & Smart Meters

Bart, Depending on your state you might be required to have the smart meter. In Pennsylvania there is a law that all customers will be switched to smart meters. solarvic

Blackcherry04

Re: Solar & Smart Meters

Thats why they call it a " Net meter " , after my second call they got someone to explain it to me and it was crystal clear.....lol

solar_dave

Re: Solar & Smart Meters

Bart I am not sure how you have your TED setup, with a dual CT setup you need to have one set on your mains and then the other on your solar. Then tell ted the configuration is Load and Generation combined on the mains CT/MTU and generation on the Solar back feed CT/MTU. Footprints will then do the math correctly.

http://www.theenergydetective.com/solar_installation
Shows the installation diagram for the various install types. If you back feed your main panel and have CT setup on the main line and the solar back feed then you have to call the main CT/MTU "adjusted" so it can do the subtraction properly and separate your back feed from your loads per the left hand diagram in the link.

I have mine setup as pure generation and isolate all the loads so mine is setup as pure loads (on 3 CT/MTUs house, shop/office, Volt chargers) and generation (on a separate CT/MTU).