Battery / Grid inverter that stops grid import.

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ALAN/ALAN D

Battery / Grid inverter that stops grid import.

#1

Post by ALAN/ALAN D »

Hello Gents.
Is there a battery fed grid inverter that will detect with a current transformer that the house is using power from the grid and send power back to stop importing energy.
A system that will still work with wind / p.v. inverters and power diverters all ready connected to the grid.
Just want to end up not importing any power.
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nowty
Posts: 5144
Joined: Mon May 31, 2021 2:36 pm
Location: South Coast

Re: Battery / Grid inverter that stops grid import.

#2

Post by nowty »

ALAN/ALAN D wrote: Sun Oct 02, 2022 11:42 pm Hello Gents.
Is there a battery fed grid inverter that will detect with a current transformer that the house is using power from the grid and send power back to stop importing energy.
A system that will still work with wind / p.v. inverters and power diverters all ready connected to the grid.
Just want to end up not importing any power.
Thats what battery inverters do. :?:

Some are not 100% accurate and some allow you to set an offset to increase any inherent inaccuracy.
With regards to diverters, if the diverter can be set to a minimum export figure it still works ok.

Example of my battery inverter, house using 12.2kW, solar PV generating 7kW and the battery inverter kicking out 5.2kW to prevent any import from grid.
Image
15.2kW PV > 100MWh generated
Ripple 6.6kW Wind + 4.5kW PV > 19MWh generated
5 Other RE Coop's
105kWh EV storage
60kWh Home battery storage
40kWh Thermal storage
GSHP + A2A HP's
Rain water use > 490 m3
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Stinsy
Posts: 2640
Joined: Wed Jun 02, 2021 1:09 pm

Re: Battery / Grid inverter that stops grid import.

#3

Post by Stinsy »

ALAN/ALAN D wrote: Sun Oct 02, 2022 11:42 pm Hello Gents.
Is there a battery fed grid inverter that will detect with a current transformer that the house is using power from the grid and send power back to stop importing energy.
A system that will still work with wind / p.v. inverters and power diverters all ready connected to the grid.
Just want to end up not importing any power.
Yep all of them do that!
12x 340W JA Solar panels (4.08kWp)
3x 380W JA Solar panels (1.14kWp)
5x 2.4kWh Pylontech batteries (12kWh)
LuxPower inverter/charger

(Artist formally known as ******, well it should be obvious enough to those for whom such things are important.)
Oldgreybeard
Posts: 1873
Joined: Thu Sep 09, 2021 3:42 pm
Location: North East Dorset

Re: Battery / Grid inverter that stops grid import.

#4

Post by Oldgreybeard »

ALAN/ALAN D wrote: Sun Oct 02, 2022 11:42 pm Hello Gents.
Is there a battery fed grid inverter that will detect with a current transformer that the house is using power from the grid and send power back to stop importing energy.
A system that will still work with wind / p.v. inverters and power diverters all ready connected to the grid.
Just want to end up not importing any power.
To give you an idea of the effectiveness, we only have solar and batteries (so mostly reduce grid import during the day). Since 1st April this year (about the start of the decent generation season) we have imported a total of 16kWh from the grid during the day. The only daytime grid import is if we have a high peak demand that the battery plus the PV can't quite meet. This results is us using about 2 to 3kWh per month during the day. If the inverter peak output was higher than the 3kW unit we have we could save that 2 to 3kWh/month, but the economics don't stack up to invest so my more for such a small saving (might save us as much as £10 a year, may be).
25 off 250W Perlight solar panels, installed 2014, with a 6kW PowerOne inverter, about 6,000kWh/year generated
6 off Pylontech US3000C batteries, with a Sofar ME3000SP inverter
ALAN/ALAN D

Re: Battery / Grid inverter that stops grid import.

#5

Post by ALAN/ALAN D »

Thank you Gents.

If the inverter fails / Battery problem. All things plugged into grid keep working. ?
I have got lead acid / gell batteries. 48 volt.
My diverter is many years old. No offset option.
At the moment the batteries are about 150ft away from the grid 60amp fuse.
They can be moved closer to the current transformer required at the grid fuse.

Any suggestions for
Inverter type.
Diverter.
Grid connected Wind / P.V. inverters still require to be connected for fits.
ALAN/ALAN D

Re: Battery / Grid inverter that stops grid import.

#6

Post by ALAN/ALAN D »

Hello Gents.
I am getting a bit Fed Up with my Off Grid bits.
Second time I got up in the morning and the off grid inverter has shut down. Saying battery voltage low. Luckily no water coming out from the bottom of the fridge freezer.
It was not low. Had been charging on Economy 7 over night.
Off Grid days are over.
How about one of these.

https://www.ebay.co.uk/itm/394068066122 ... 01&mkevt=1

It says it will stop generating if the power is being exported. I was going to feed it with batteries.

Quote. “ Why we produced the GRID TIE INVERTER WITH LIMITER
It is in response to the overwhelming clamor from our customers for a product that can control the amount of power that the grid tie inverters (GTI) can generate so that the amount of excess power produced by the solar panels are reduced to insignificant levels, if not eliminated --- because in some countries,the producer pays for the excess power it gives to the distribution grid. This is because the electric power meters (the one provided by the electricity provider in the area) are not aware of the direction of power flow. In other words it only adds even if power is exported to the grid, thus, the consumers will be charged for power even if it is given to the grid, and this is the problem

This is the 2nd generation grid tie inverter with limiter. “
Which is exactly what I want.
Hopefully it will work with the other wind turbine / P.V. systems connected to the grid here.
If I put the current transformer before the Immersun current transformer Hopefully it might work. ?
Does any one know of any other inverters powered from wind / P.V. / Battery / that will not export any power.
I am only paying for very little amount of units.
I just want a system where the fridge is still working when I get up.
Has any one tried one of these.
Any other suggestions that will work with the existing grid inverters.
Countrypaul
Posts: 473
Joined: Sun Jul 18, 2021 11:50 am

Re: Battery / Grid inverter that stops grid import.

#7

Post by Countrypaul »

Have you looked at the Victron Multiplus range? From what I have read they support multiple inputs PV/Gen/Wind, batteries, can allow a FITS system to be used as an input, can control export, can provide power if the grid fails, allow batteries to be charged from PV (without inverting, transforming and rectifying. I think someone on the forum strongly reccomends Victron, Clockman?
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Stinsy
Posts: 2640
Joined: Wed Jun 02, 2021 1:09 pm

Re: Battery / Grid inverter that stops grid import.

#8

Post by Stinsy »

ALAN/ALAN D wrote: Mon Oct 03, 2022 9:15 am Thank you Gents.
No problem.
ALAN/ALAN D wrote: Mon Oct 03, 2022 9:15 am If the inverter fails / Battery problem. All things plugged into grid keep working. ?
Correct. The grid is the first supplier, the inverter adjusts its charge/discharge rate constantly in attempt to keep zero import/export.
ALAN/ALAN D wrote: Mon Oct 03, 2022 9:15 am I have got lead acid / gell batteries. 48 volt.
My diverter is many years old. No offset option.
At the moment the batteries are about 150ft away from the grid 60amp fuse.
They can be moved closer to the current transformer required at the grid fuse.

Any suggestions for
Inverter type.
Diverter.
Grid connected Wind / P.V. inverters still require to be connected for fits.
Lead-acid batteries are obsolete nowadays. They're just too inefficient, temperamental, and have a short lifespan. Now that the price of LiFePO4 batteries has come down so much, they are standard solution.

Pretty much any inverter will work with both your Lead and LiFePO4 batteries. Solax, SoFar, Solis, and others, are all much-of-a-muchness at the bottom end of the market. The technology is mature so even the cheapo models are reliable. Victron inverters have many more features and integrate nicely with a bewildering array of kit, but they come with a premium price.

I wouldn't worry about the location of the batteries. Running a length of CAT5e cable is probably easier than moving the batteries!
12x 340W JA Solar panels (4.08kWp)
3x 380W JA Solar panels (1.14kWp)
5x 2.4kWh Pylontech batteries (12kWh)
LuxPower inverter/charger

(Artist formally known as ******, well it should be obvious enough to those for whom such things are important.)
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