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Comment by NortySpock | Hacker News Reader

Seems like an opportunity for a massive battery system similar to the Hornsdale Power Reserve in Australia that Tesla pulled out all the stops for.

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"Massive" Honsdale battery is capable of supplying much less than 1% of grid power in Australia. An installation of that size could help at the margins to prevent some brownout events, but don't overestimate the capacity of batteries compared to grid demand. It looks like Costa Rica has about 3600 MW of generating capacity. The Hornsdale battery is good for 150 MW.

Would be good for those 5 second brownouts though

Flywheels are a pretty good solution for ride-through of brownouts. Fairly compact and instantly available.

Where are they deployed at scale?

Hospitals, datacenters. Plenty of them to ensure that operation theater gear continues to work uninterrupted in case of brown out or the - short - interval during which generators start up if the power should fail.

Teraloop, AFS and others.

Literally everywhere. They're standard issue.

The Level3 building in San Diego had a two story iron flywheel that got loose and cut its way through the highway.

They are by far the most common kind of energy storage on Earth. Even in your car, which has both.

https://www.10news.com/news/11k-pound-flywheel-caused-poway-...

The battery is for one state, not the country. Batteries only need to cover intermittent load, not 100% of generated load… so the difference in MW doesn’t mean anything without knowing how long generation is reduced for and the net negative that occurs on the grid

You don't have to supply the entire grid demand - only smooth out the brownouts, which something the size of Hornsdale would likely be able to do for Costa Rica

Note that Hornsdale is also tiny compared to batteries currently being developed in Australia. The new battery in the Hunter will be 1200MW - which is enough to nullify the need for all gas-generated peaking capacity in that state

As someone who knows very little about power systems - is this true? Watts are a unit of instantaneous energy delivery, so if the whole system browns out then doesn’t the battery need to handle 100% of the load? I guess I would expect the entire system not to drop at the same time but worth asking if someone knew this.

I'm assuming a brownout is usually a drop in voltage (a reduction in output power), so a backup battery wouldn't need to handle 100% of the load, just some fraction, for a short period of time.

Worth noting that of that 150MW, only about 70MW over 10 minutes is available to the government to stabilize the grid. The remaining capacity is reserved for the Neoen (the privately owned energy company running the facility) to buffer energy prices by storing excess energy when prices are low.

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