alt Hacker NewsFrom what I understand, most homes that are connected to both solar and the grid require the grid to be active to produce solar. This is for two reasons. One, not to endanger lineman working on the grid. And two, the solar AC cycle must be synchronized with the grid AC cycle.
Are these homes not also connected to the grid? Or is there some technology that addresses these two issues that are in use in Puerto Rico?
Replies
If you use a string inverter not a emphase style microinverter, most of them are capable of running without the grid- Particularly if you add any sort of battery system.
These use a form of transfer switch like you’d use when you connect a generator- they disconnect the upstream.
If your home is isolated from the grid you don't have to worry about syncing your 50/60 Hz. A UPS during a blackout is an example. I experienced it myself.
I have no idea about the hurdles of keeping in sync many batteries in many homes connected together. This is not even something I thought about before the news of the blackout in Spain months ago.
This is true, but if you add in local batteries attached to the solar, you can have a device that works in basically all situations. If disconnected from the grid, it can run off battery instead of just not working.
I haven't read the OP link yet, but my guess is they are doing something like this: Grid, Solar and batteries.
Microgrids use specialized inverters with islanding capability and automatic transfer switches that disconnect from the main grid during outages, allowing them to operate independently while maintaining their own frequency regulation.
It's just a coordination problem.
You are also sort of conflating "loss of interconnect" with "outage'.
I think you're looking for the term "islanding".
It's becoming more and more common for PV systems with a battery system to be able to work in an islanded mode, and more importantly - they're legal and code compliant to do so.
When the grid goes down/out of spec, they disconnect the home from the grid and continue to power locally.
Examples of this include Tesla and Sigenergy.
Some are able to do this in very short periods and able to operate effectively as a whole-house UPS. Some will have a flickr of the lights and maybe some sensitive devices will restart. Others will take some period of time to disconnect from the grid and run in islanded mode.