Renewable Energy Sources are Making Gains

[OmCheeto]

I don't understand how anti-islanding protection can work if you just plug the panels and their inverters into a wall outlet. How is the house "island" disconnected from the grid during a power outage?

https://blog.windurance.com/how-does-anti-islanding-work

I'm guessing there's a third 'grid aware' device, other than the dimwitted panel and inverter devices, that senses the power outage.

I could tell you how I would do it, but my working knowledge of power distribution is now nearly 50 years old.

Given that caveat, I will say I would design the 'plug in systems' to simply turn off if voltage drops below a certain value.

 

[DaveE]

I don't understand how anti-islanding protection can work if you just plug the panels and their inverters into a wall outlet. How is the house "island" disconnected from the grid during a power outage?

https://blog.windurance.com/how-does-anti-islanding-work

The inverters disconnect if the grid goes down. Just like conventional roof top solar. In California, you aren't allowed to DIY these things, they must meet regulatory requirements.

 

[berkeman]

The inverters disconnect if the grid goes down.

But how can these disconnect from the grid if they're just plugged into a wall socket. Do they somehow sense it the socket is powered while they are feeding the same voltage and phase into the wall socket?

 

[DaveE]

But how can these disconnect from the grid if they're just plugged into a wall socket. Do they somehow sense it the socket is powered while they are feeding the same voltage and phase into the wall socket?

Yes.

They control the power flow by matching (leading slightly) the phase of the grid. So they are always sensing it, If their frequency requirement shifts out of range, they shut down. Some will actively probe the grid by introducing a small frequency variation and monitoring how the current (power) flow changes in response.

Again, no different that the big panels on the roof. Power sources from giant to small are always monitoring and adjusting to the grid to control power flow.