Regarding the grid tied PV suggested for USA, this gives rise to the problem we have in this country where it is possible to push the fault level over the capability of the transmission switchgear. This has led to projects such as the one with UK Power Networks : https://innovation.ukpowernetworks.co.uk/projects/powerful-cb/ which will allow more distributed generation to be connected.

As far as the 110/220V supplies of Brasil is concerned, I spent a number of years in South Korea which had a similar system, albeit with different sockets/plugs - American flat pin 110V and round pin 220V - and my flat had a mixture of both types (though I measured the voltages and they were actually 120V and 208V). The interesting aspect was that you could readily buy transformers to convert between the voltages, particularly 110-220 (some older flats only had one set of sockets) and new equipment could generally be switched between the voltages anyway. Adaptors to plug into either socket were also readily available. A stark warning was issued as a Norwegian visiting had brought his (230V) fax machine and to get it to work had bought a 110V/220V and plugged it in to (you guessed it) a 220V socket. It can be reported that the survival time of 230V equipment on 440V (or at least 416V) is not measurable on a stopwatch.......

Alasdair

Regarding the grid tied PV suggested for USA, this gives rise to the problem we have in this country where it is possible to push the fault level over the capability of the transmission switchgear. This has led to projects such as the one with UK Power Networks : https://innovation.ukpowernetworks.co.uk/projects/powerful-cb/ which will allow more distributed generation to be connected.

As far as the 110/220V supplies of Brasil is concerned, I spent a number of years in South Korea which had a similar system, albeit with different sockets/plugs - American flat pin 110V and round pin 220V - and my flat had a mixture of both types (though I measured the voltages and they were actually 120V and 208V). The interesting aspect was that you could readily buy transformers to convert between the voltages, particularly 110-220 (some older flats only had one set of sockets) and new equipment could generally be switched between the voltages anyway. Adaptors to plug into either socket were also readily available. A stark warning was issued as a Norwegian visiting had brought his (230V) fax machine and to get it to work had bought a 110V/220V and plugged it in to (you guessed it) a 220V socket. It can be reported that the survival time of 230V equipment on 440V (or at least 416V) is not measurable on a stopwatch.......

Alasdair