Author Topic: Grid Tied inverters for household use will soon be useless?  (Read 3459 times)

0 Members and 1 Guest are viewing this topic.

Online Cerebus

  • Super Contributor
  • ***
  • Posts: 9164
  • Country: gb
Re: Grid Tied inverters for household use will soon be useless?
« Reply #25 on: September 19, 2021, 02:05:47 pm »
With electricity rates tied to peak hours, I don’t think to many Tesla owners are charging when they come home at 5pm, that would be foolish.

An assumption based on your domestic market that doesn't translate to a whole world picture. Some places have peak pricing, some don't.

For instance, in the UK domestic market we don't generally have peak pricing although some alternative providers are now experimenting with it; we have an off-peak overnight tariff (typically midnight-7AM) that can be used for storage heaters and the like and have had that for a long time. Perhaps the canniest UK EV users are using off-peak pricing but I suspect most don't give any consideration to what time it is when they plug in to charge - the peak pricing disincentive just isn't there.
Anybody got a syringe I can use to squeeze the magic smoke back into this?
 
The following users thanked this post: Someone, Faringdon

Online Jester

  • Frequent Contributor
  • **
  • Posts: 594
  • Country: ca
Re: Grid Tied inverters for household use will soon be useless?
« Reply #26 on: September 20, 2021, 11:33:02 am »
With electricity rates tied to peak hours, I don’t think to many Tesla owners are charging when they come home at 5pm, that would be foolish.

An assumption based on your domestic market that doesn't translate to a whole world picture. Some places have peak pricing, some don't.

For instance, in the UK domestic market we don't generally have peak pricing although some alternative providers are now experimenting with it; we have an off-peak overnight tariff (typically midnight-7AM) that can be used for storage heaters and the like and have had that for a long time. Perhaps the canniest UK EV users are using off-peak pricing but I suspect most don't give any consideration to what time it is when they plug in to charge - the peak pricing disincentive just isn't there.

Good point, apparently (first google hit), smart meter deployment is > 40% worldwide, 67% in North America. First comes the smart meter followed shortly after with peak pricing, it won’t be long.
« Last Edit: September 20, 2021, 11:36:24 am by Jester »
 
The following users thanked this post: BrokenYugo, Faringdon

Online Cerebus

  • Super Contributor
  • ***
  • Posts: 9164
  • Country: gb
Re: Grid Tied inverters for household use will soon be useless?
« Reply #27 on: September 20, 2021, 12:48:04 pm »
Good point, apparently (first google hit), smart meter deployment is > 40% worldwide, 67% in North America. First comes the smart meter followed shortly after with peak pricing, it won’t be long.

It won't for the UK then because smart meters will never be universal here as there's a "right to refuse" enshrined in law so they just can't do it. If they tried to invent a new "you don't have a smart meter" tariff they would soon get pummelled (by the courts) for punishing people for exercising their rights.

I'm actually a smart meter refusenik, for two reasons. (1) The ability to remotely extract usage patterns for individual households is a proxy for "when is this house unoccupied". When, not if, but when some bunch of organised housebreakers get their hands on this data it's obvious what will happen. (2) The ability to remotely cut off electricity. I don't want to be in the situation where someone makes a mistake about a bill having been paid or not and can cut me off remotely. If you have to send a body out to cut me off (a) I can stop them and say "no, you've made a mistake" (b) bodies going out is expensive, remote cutoff isn't - ergo eventually the time between "payment overdue" and "cutoff" will get shorter and shorter and the grace period you currently enjoy if there's a genuine mistake, or you're just desperately waiting for payday will vanish.
Anybody got a syringe I can use to squeeze the magic smoke back into this?
 
The following users thanked this post: Faringdon

Offline tszaboo

  • Super Contributor
  • ***
  • Posts: 5773
  • Country: nl
  • Current job: ATEX certified product design
Re: Grid Tied inverters for household use will soon be useless?
« Reply #28 on: September 20, 2021, 01:34:16 pm »
Yes, this is an issue already. Belgium has great solar penetration, and it affects customers.
That being said, we analyzed about 10K solar installations, with "big data", and only a few % of customers lost income more or less 50 EUR per year. This can be prevented if the DSO installs larger diameter cables (fat chance) or changes the feedline transformer turns ratio. Old transformers were installed so that the house closes to the feed line has as high voltage as possible. If you reduce that voltage, the issue becomes lesser.

The extra energy can be used to generate apparent power BTW. Basically reducing the slip between the current and voltage. This thing costs a lot of money. Or orient the panels to "less than optimal" azimuth. West facing solar installations might generate less power, but it can do it in times, when it is actually needed.
Former username: NANDBlog
 
The following users thanked this post: Faringdon

Offline richard.cs

  • Super Contributor
  • ***
  • Posts: 1129
  • Country: gb
  • Electronics engineer from Southampton, UK.
    • Random stuff I've built (mostly non-electronic and fairly dated).
Re: Grid Tied inverters for household use will soon be useless?
« Reply #29 on: September 20, 2021, 02:10:27 pm »
It won't for the UK then because smart meters will never be universal here as there's a "right to refuse" enshrined in law so they just can't do it. If they tried to invent a new "you don't have a smart meter" tariff they would soon get pummelled (by the courts) for punishing people for exercising their rights.
Everything I've read suggests that you can refuse to have one installed in the short term, but when your current meter reaches end of life (basically when the calibration expires) you can't refuse a meter change, and they are not obligated to offer you a dumb meter at that point.

https://www.smartme.co.uk/customer-rights.html

In any case the law can and probably will change over time.
 
The following users thanked this post: Faringdon

Offline madires

  • Super Contributor
  • ***
  • Posts: 6375
  • Country: de
  • A qualified hobbyist ;)
Re: Grid Tied inverters for household use will soon be useless?
« Reply #30 on: September 20, 2021, 02:13:11 pm »
Looking at reference designs for universal input power supplies, they're tested up to 265V, some up to 270V.

You seem to be making the unwarranted assumption there that everything connected to the mains has an SMPS at the front of it. This is not the case.

Back in the 220 V era EEs were taught that PSUs should support a tolerance of +/- 10 %. So old devices (many with transformers) should be fine up to 242 V. BTW, in my case there are a few PV installations in the neighborhood (maybe 30 - 50 kW in total) and the mains voltage is around 236 V.
« Last Edit: September 20, 2021, 02:16:52 pm by madires »
 
The following users thanked this post: Faringdon

Offline madires

  • Super Contributor
  • ***
  • Posts: 6375
  • Country: de
  • A qualified hobbyist ;)
Re: Grid Tied inverters for household use will soon be useless?
« Reply #31 on: September 20, 2021, 02:19:41 pm »
It won't for the UK then because smart meters will never be universal here as there's a "right to refuse" enshrined in law so they just can't do it. If they tried to invent a new "you don't have a smart meter" tariff they would soon get pummelled (by the courts) for punishing people for exercising their rights.
Everything I've read suggests that you can refuse to have one installed in the short term, but when your current meter reaches end of life (basically when the calibration expires) you can't refuse a meter change, and they are not obligated to offer you a dumb meter at that point.

Over here you'll get a smart meter when your power consumption exceeds 6000 kWh per year or if you feed power into the grid.
 
The following users thanked this post: Faringdon

Offline themadhippy

  • Frequent Contributor
  • **
  • Posts: 864
  • Country: gb
Re: Grid Tied inverters for household use will soon be useless?
« Reply #32 on: September 20, 2021, 03:17:03 pm »
Quote
If they tried to invent a new "you don't have a smart meter" tariff they would soon get pummelled (by the courts) for punishing people for exercising their rights.
Without a smart meter good luck getting the cheapest energy price  from most suppliers
 
The following users thanked this post: Faringdon

Offline Gyro

  • Super Contributor
  • ***
  • Posts: 7452
  • Country: gb
Re: Grid Tied inverters for household use will soon be useless?
« Reply #33 on: September 20, 2021, 07:48:25 pm »
Quote
If they tried to invent a new "you don't have a smart meter" tariff they would soon get pummelled (by the courts) for punishing people for exercising their rights.
Without a smart meter good luck getting the cheapest energy price  from most suppliers

Yes, it's become a condition that you have one fitted for some tariffs. It worked for me though, I got a free mains isolator and tails upgraded to 100A 25mm2 out of it (you have to remember to ask the fitter nicely mind you ;)).
Regards, Chris

"Victor Meldrew, the Crimson Avenger!"
 
The following users thanked this post: Faringdon

Offline Shivamraj243

  • Newbie
  • Posts: 1
  • Country: in
Re: Grid Tied inverters for household use will soon be useless?
« Reply #34 on: September 26, 2021, 10:49:53 am »
you can also go to google
 
The following users thanked this post: Faringdon

Offline Faringdon

  • Frequent Contributor
  • **
  • !
  • Posts: 434
  • Country: gb
Re: Grid Tied inverters for household use will soon be useless?
« Reply #35 on: October 10, 2021, 02:10:48 pm »
Actually, this video,
https://www.eevblog.com/2021/10/10/eevblog-1426-this-problem-can-drop-solar-output-by-20/
..at approx 7:50,  brings into question  that GTI's can possibly deliver into voltages above 253Vac.

This is above 230VAC +10%.

So this would, in fact,  kind of squash the theory that GTI's will all start cutting out when mains goes above 253V. It was also mentioned that the upper trip point may possibly  be user programmable.......so this has flummoxed me.

However, i am sure there is some  regulation somewhere which says that GTIs (at least in UK/AUS/EU) must trip out at 230 -10%,+10%?

The video does suggest that GTI's  can possibly raise the mains voltage......which doesnt bode well for GTI's in a neighbourhood where there is no big battery bank to keep the mains voltage from rising away.
« Last Edit: October 10, 2021, 03:36:19 pm by Faringdon »
 

Online Cerebus

  • Super Contributor
  • ***
  • Posts: 9164
  • Country: gb
Re: Grid Tied inverters for household use will soon be useless?
« Reply #36 on: October 10, 2021, 04:50:19 pm »
It's almost as if someone slept though their year 1 lectures on Kirchhoff, Thévenin and Norton.
Anybody got a syringe I can use to squeeze the magic smoke back into this?
 
The following users thanked this post: Faringdon

Online mansaxel

  • Super Contributor
  • ***
  • Posts: 2738
  • Country: se
  • SA0XLR
    • My very static home page
Re: Grid Tied inverters for household use will soon be useless?
« Reply #37 on: October 10, 2021, 05:28:16 pm »
Here, all new construction 1-family houses since 1973 or so (oil crisis) are required to be 3x10mm2+10mm2 and 35A capable. Three-phase. Frankly, I'd be really cross with the power utility if my voltage was down at 265V. Hovering around 400 is more like it.   :-DD :-DD

We live close to a water tower, which has a priority power requirement, so we're very well connected, due to sharing the transformer with the water tower.

I just got a new, smart meter, same style as in Netherlands. The law here is crystal clear; the power utility owns the meter and can swap it as they see fit.

With this meter generation, the ability to measure power both ways is introduced. I can get one reading per second locally too, if I connect the right gadget. Which I will.

Online alexnoot

  • Contributor
  • Posts: 21
  • Country: aq
Re: Grid Tied inverters for household use will soon be useless?
« Reply #38 on: October 10, 2021, 05:48:52 pm »
Frankly, I'd be really cross with the power utility if my voltage was down at 265V. Hovering around 400 is more like it.   :-DD :-DD
I'm not sure if you're being serious, but the 253V mentioned is the voltage across live and neutral. Australia is a 400V country as well... At 253V L-N, the L-L voltage would be about 438V. The official voltage across Europe (and I'm guessing AU as well) is 230V +/- 10%, meaning between 207V and 253V. Obviously neither extreme is good in the long run, but that's the standard. In my neighbourhood in Norway I'm averaging about 240V, from data collected the past 90 days. My max is 249V, and the min is 236V. And there's literally no solar around here, so you can't blame that.

Also, Faringdon has a habit of starting a ton of threads with somewhat insane arguements about everything and anything. I'm still waiting for him to finish his electric vehicle charger, the one with all the safety features and expensive components removed. Meanwhile he's saying Tesla's Powerwall will fail at 10 years due to cheap capacitors. So I'm not really sure what he's on about.
« Last Edit: October 10, 2021, 05:51:46 pm by alexnoot »
 
The following users thanked this post: Faringdon

Online mansaxel

  • Super Contributor
  • ***
  • Posts: 2738
  • Country: se
  • SA0XLR
    • My very static home page
Re: Grid Tied inverters for household use will soon be useless?
« Reply #39 on: October 10, 2021, 06:01:30 pm »
Frankly, I'd be really cross with the power utility if my voltage was down at 265V. Hovering around 400 is more like it.   :-DD :-DD
I'm not sure if you're being serious,

Oh, in part, but only as far as just before starting to point fingers at the part of the world that does not give residential homes the default of three-phase mains. That is something I usually blame Edison for, and is as close to "asocial thread-hijacking" that I'll go.  ;D

Finally, I know next to nothing about electricks, but I can plainly see the errors in Faringdon's interpretation of perceived phenomena. Even with a loaded low voltage grid, the larger grid on the other side of the transformer is mostly going to be low enough impedance that local voltage surges are going to be eaten. And, coincidentally, a significant residential load in countries where people install solar is air condition, which will consume at precisely the times when solar is working at peak. I do concur that there are large local variations in this, and it is not unthinkable that problems could emerge. But a general inability to handle local production, no.


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf