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Comment by robocop_legacy | Hacker News Reader

“ According to numbers provided by the company, 590 Gogoro battery-swap locations (some of which have more than one swap station) stopped drawing electricity from the grid, lowering local demand by a total six megawatts—enough to power thousands of homes.”

From the title I thought the batteries would stabilize the grid by discharging back into it but apparently that capability is not implemented yet. Still interesting that the stations increase demand enough that grid stabilization can occur by simply disabling battery charging.

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> Still interesting that the stations increase demand enough that grid stabilization can occur by simply disabling battery charging.

That trick is not limited to battery stations. Another thing which is done in some places (at least my country does that), is to have some circuits from substations configured so that they cut power when the frequency drops too low and/or too fast, preventing a generalized blackout at the cost of temporarily losing power to parts of the system (the circuits to be powered down in each step are chosen so that important loads like hospitals do not lose power). In the country-wide blackout last year (https://en.wikipedia.org/wiki/2023_Brazil_blackout), that mechanism stabilized power in the southern part of the country, allowing it to recover quickly (the northern part, where the disturbance originated, unfortunately lost too much transmission and generation, and needed a black start).

I'm bivalent on this topic. On one hand 6MW is very little, compared to 3,200 MW lost power during the earthquake, especially when spread over 580 stations. It's likely the feature to disconnect when frequency drops is designed to protect the station, rather than the grid. In general, this sounds like a feel-good story rather than a something real.

That being said, I see this as a huge opportunity to stabilize the grid by having large-ish battery stations discharging their stored power when frequency drops. It's likely this will need to be grid controlled rather than individual and decentralized completely. It's hard (for me) to say what needs to be built first: an automatic way to reduce power draw from the grid by large consumers that are non-essential (eg. industry) or battery stations that can keep the frequency stable in case of brownouts.

I spent a short while going down the rabbit whole of the meaning of bivalent, and how that applies to this scenario/phrasing - before I realised it was likely a typo for ambivalent.

I agree, more of a feel good/marketing piece. Bad electric coming into a system can cause damage so protection circuits are built in to prevent that damage from happening. I wonder how many UPSs kicked in and also lowered demand. What about poorly designed devices that stopped working?

A huge part of previously installed grid scale battery power (like famous pilot Tesla plants in Australia) were precisely for frequency stability. Considerable portion of automatic cutoff or otherwise curtailment support systems in smart meters and the like is also related to grid stability contracts. Sometimes it's as little as "giving more time for steam generator to up the pressure" while wind/solar wanes, but it means there's less load on turbines which means there's less desynchronization which means less possibility of catastrophic failure due to unexpected flows in the grid.

So, 6MW might be a little, and the comparison suggests it enabled more power for houses, but such little details can mean considerable differences in keeping grid frequency in sync and preventing further outage

I wrote a book on the topic of virtual power plants, and it's amazing how supply and demand have to match exactly in an electrical system, so reducing power use is the same thing as increasing power use!

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