Current limiting

[slowbutsure]

Hi

Anyone know of a way to ensure current does not back feed to the grid without using a limiter that connects to the inverter? For example is there a a breaker with a diode that ensures current only flows one way? Thanks.

 

[MisterSandals]

connects to the inverter?

What inverter?

It sounds like you have a non-compliant inverter connected to the grid.

 

[slowbutsure]

What inverter?

It sounds like you have a non-compliant inverter connected to the grid.

I live in the Philippines, there is no such thing as non-compliant here! Not grid connected yet. I bought a cheap imverter from China (my mistake) and it has no connection for a limiter.

 

[740GLE]

If nothing is non-compliant why worry about it?

 

[slowbutsure]

If nothing is non-compliant why worry about it?

Because if it feeds back energy to the grid I will receive a very large electricity bill.

 

[timselectric]

What inverter?
If it's not a grid-tied capable inverter. Do not let it feed the grid. Unless you like watching smoke come out of things.

 

[DIYrich]

For example is there a a breaker with a diode that ensures current only flows one way? Thanks.

I don't think there is such a thing as an AC diode.

 

[slowbutsure]

I don't think there is such a thing as an AC diode.

I can’t imagine there isn’t an equivalent to it?

 

[740GLE]

Because if it feeds back energy to the grid I will receive a very large electricity bill.

have you proven this? What style meter do you have?

 

[slowbutsure]

have you proven this? What style meter do you have?

Yes. You have to use some kind of limiter here. Meter is not installed yet but it is a fact here, unfortunately.

 

[slowbutsure]

Question. How does this backfeeding thing happen?

The inverter produces power according to load to supply the load. It doesn’t produce more than the load, as I understand it. So where does the extra backfeeding come from? Just trying to understand.

 

[SpongeboB Sinewave]

Question. How does this backfeeding thing happen?

The inverter produces power according to load to supply the load. It doesn’t produce more than the load, as I understand it. So where does the extra backfeeding come from? Just trying to understand.

The inverter connects itself to the grid so that it can charge the batteries. The inverter tries to keep the energy flowing into the house but at low charging power, it is hard to keep it exactly balanced. If, at lower power draw from the grid, there are large load changes, the inverter may sell back to the grid some but momentarily and should come back around quickly, too. Unless the inverter/charger is TRYING to sell back to the grid. It all depends on the software in the inverter/charger and possibly your utility power meter.

AFAIK, there is no AC diode like product out there.

boB

 

[timselectric]

Question. How does this backfeeding thing happen?

The inverter produces power according to load to supply the load. It doesn’t produce more than the load, as I understand it. So where does the extra backfeeding come from? Just trying to understand.

If it is a grid-tied inverter. It produces everything it can and pushes it to the grid meter.
If your loads are less than what it produces, the rest goes to the grid.

 

[Ampster]

For example is there a a breaker with a diode that ensures current only flows one way?

A breaker would be herky jerky having to reset it all the time. A diode wouldn't work because the grid is AC. The best idea has already been suggested, buy an inverter which has a zero export setting. I actually have an export agreement with my power company for 6.6 kWs of export. I added more panels and limit my export to 7 kW which keeps me under the 1kW I can add without going to a less favorable NEM agreement.

 

[DIYrich]

Question. How does this backfeeding thing happen?

The inverter produces power according to load to supply the load. It doesn’t produce more than the load, as I understand it. So where does the extra backfeeding come from? Just trying to understand.

Inverter produces X to power Load of X. AC shuts off, and load goes to something a lot less than X. Inverter continues producing X for a short period before it can sense the drop in Load and reduce production. That excess power has to go somewhere. If batteries are full, it goes to the Grid.

 

[Texas-Mark]

Because if it feeds back energy to the grid I will receive a very large electricity bill.

Can you elaborate on this? Why would you get a very large bill? Some sort of fine?

 

[kommando]

They have the same problem in France, their meters count incoming and outgoing energy as all incoming and charge accordingly.

This is the device they use to prevent overcharging, it sends any excess PV to a resistive load ie an immersion heater.

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