I had a chat about this with a friend who works for the national grid (UK).
Apparently the problem is keeping the grid balanced and stable. Basically, the grid struggles to react fast, so they plan ahead. Things like large scale solar can provide predictions on output. Home solar can’t.
When clouds pass over an area it can cause slumps and surges in the local grid. The more home solar, the worse it gets. The current grid is designed to work top down, with predictable changes in demand. It needs upgrading to deal with large scale bidirectional flows.
The plug in units are (potentially) even more ropey. If used properly, they are no worse than normal home solar. Unfortunately, being cheaper, there are worries over the microinverters not shutting down. Either due to the manufacturer cheaping out, or turning on an “off grid” mode.
There are also worries about overloading household circuits. Back feeding bypasses the household circuit breakers and RCDs. They could overload wall wiring and cause fires, or stop an RCD tripping, allowing for a person to be shocked.
I don’t know how much this would apply to the American Grid, but I would imagine it would be worse. Your grid is older and larger. You also use 120VAC which makes the current overload issue a lot worse.
You also use 120VAC which makes the current overload issue a lot worse.
Voltage inside of residences is 120v AC, but its 240v thats delivered to each house. I think a bigger difference is that in the USA that 240v AC is single phase where I believe (Germany included) many nations in the EU are 3 phase.
The USA does have 3 phase power for most commercial applications though.
I had a chat about this with a friend who works for the national grid (UK).
Apparently the problem is keeping the grid balanced and stable. Basically, the grid struggles to react fast, so they plan ahead. Things like large scale solar can provide predictions on output. Home solar can’t.
When clouds pass over an area it can cause slumps and surges in the local grid. The more home solar, the worse it gets. The current grid is designed to work top down, with predictable changes in demand. It needs upgrading to deal with large scale bidirectional flows.
The plug in units are (potentially) even more ropey. If used properly, they are no worse than normal home solar. Unfortunately, being cheaper, there are worries over the microinverters not shutting down. Either due to the manufacturer cheaping out, or turning on an “off grid” mode.
There are also worries about overloading household circuits. Back feeding bypasses the household circuit breakers and RCDs. They could overload wall wiring and cause fires, or stop an RCD tripping, allowing for a person to be shocked.
I don’t know how much this would apply to the American Grid, but I would imagine it would be worse. Your grid is older and larger. You also use 120VAC which makes the current overload issue a lot worse.
Voltage inside of residences is 120v AC, but its 240v thats delivered to each house. I think a bigger difference is that in the USA that 240v AC is single phase where I believe (Germany included) many nations in the EU are 3 phase.
The USA does have 3 phase power for most commercial applications though.