logoalt Hacker News

z2today at 4:31 PM1 replyview on HN

There are non-battery buffers available too--I recently got rooftop residential solar installed, and learned that my area is covered by a grid profile requiring that the solar system stay online through something like 60 +/- 2Hz before shutting down completely, and ramping down production linearly beyond a 1Hz deviation or so. The point is to avoid cascading shutdowns by riding through over/undersupply situations, whereas an older standard for my area would have the all solar systems cut off the moment frequency exceeded 60.5Hz (which would indicate oversupply from power plant generators spinning faster via lower resistance).

In my system's case, switching to this grid profile was just a software toggle.


Replies

toomuchtodotoday at 4:37 PM

This is grid following, very effective for small scale generation. It does not work for large scale generation though when the grid is relying on that voltage and frequency from the utility scale renewable generation ("grid forming"). When those large generators exceed their ride through tolerance, batteries step in to hold voltage and frequency up until the transient event ends or dispatchable generators called upon spin up (currently fossil gas primarily, but also nuclear if there is headroom to increase output). Thermal generators can take minutes to provide this support (called upon, fuel intake increased, spinning metal spins faster), batteries respond within 250-500ms.

Tesla’s Megapack system at the Hornsdale Power Reserve in Australia was the first example of this being proven out at scale in prod. Batteries everywhere, as quickly as possible.