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Comment by lr1970 | Hacker News Reader

lr1970

To put it in perspective. During the recent cold weather the State of Texas was short of 16GW of power for more than 40 hours making it 640GWh shortfall in amount of energy needed. You would need 6400 batteries 100MWh each to meet such demand. The only thing that a single 100MWh battery in Texas will be good for is stabilizing the grid against short-term load fluctuations -- the job a similar Tesla battery has been successfully doing in Australia.

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TFA says 100MW, not MWh. So it's not clear if this is the maximum discharge rate or the actual storage capacity.

Side note – I don't think I'll ever stop being annoyed that we use Wh instead of J for things like this, very confusing to people and makes conversions harder.

Thanks, I can't believe I've never realized that Wh and J are measuring the same thing!

Just to be clear 1 Wh is not 1 J.

3600J = 1 Wh.

Yes, a J is technically a Ws (watt-second).

Or more accurately, since Joules are the fundamental unit and Watts are a derived unit, a Watt is a J/s (Joule per second)

Damn. Never made that connection. Have a upboat

It makes a lot of sense to specify energy in Wh in electrical engineering. It's much easier to convert to other useful measurements involving volts, amps, and watts than joules are.

>It makes a lot of sense to specify energy in Wh in electrical engineering. It's much easier to convert to other useful measurements involving volts, amps, and watts than joules are.

Easier how? A watt-hour is just 3600 joules - the number of seconds in an hour.

1 joule = 1 volt * 1 amp * 1 second

1 watt-hour = 1 volt * 1 amp * 3600 seconds

Actually the article does say that the 100MW is served for about an hour that makes it 100MWh. But I do agree that it is a sloppy journaism to confuse power and energy. Basic high school level physics.

That was in reference to their Australian installation, not this new Texas one.

I remember that some facilities were shutdown because their auxiliary power generation units froze. So if batteries would only supply these mission critical apparatus their overall effect can be multiplied.

Critical facilities in locations where the grid is shut down? Well in that case a giant central battery can't help those places either, you need on-site batteries.

That is a very important job though and is dramatically cheaper than peaker plants.

‘Undeniable success’: South Australia’s 129MWh Tesla battery

https://www.energy-storage.news/news/undeniable-success-sout...

South Australia’s Tesla ‘Big Battery’ saved consumers $116 million in electricity costs last year

https://www.startupdaily.net/2020/03/south-australias-tesla-...

According to recent figures, South Australian energy prices are 51% higher than Victoria, or 134% higher than Texas.

Throwing poor people under the bus (they're most impacted by high energy prices) so you can claim you're green (while opening brand new gas power plants) is pretty awful.

South Australia is still building new gas plants. Natural gas, which is nearly as dirty as coal.

I was extremely surprised in claim that Natural gas is nearly as dirty as coal as that contradicted my intuition. So I did some Googling and was not able to find supporting evidence. Below is a quote from: https://www.gasvessel.eu/news/natural-gas-vs-coal-impact-on-...

> Natural gas is a fossil fuel, though the global warming emissions from its combustion are much lower than those from coal or oil. Natural gas emits 50 to 60 percent less carbon dioxide (CO2) when combusted in a new, efficient natural gas-power plant compared with emissions from a typical new coal plant.

From the above natural gas power plants do produce a surprising amount of CO2, but is far far better than new coal plants. Legacy coal plants also are a significant air pollution source, so if we get out of coal power plants by building out natural gas seems like a win.

Finally I checked renewables for South Australia and they seems to be doing really great at 53%, compare to U.S. at ~23%: https://indaily.com.au/news/science-and-tech/2021/01/27/sa-r...

List of currently operating power plants and the ones under constructions corroborates renewable energy percentage and actually suggests that South Australia is doing great on renewables: https://en.wikipedia.org/wiki/List_of_power_stations_in_Sout...

The trouble with natural gas is not so much at the site of combustion at the power generating plant - it is at the point of extraction, where methane leaks into the atmosphere unchecked.

https://www.nationalgeographic.com/science/article/super-pot...

Great point, I assumed that natgas was oil industry byproduct and basically free.

Thats what the industry says :-)

>Natural gas emits 50 to 60 percent less carbon dioxide

You're comparing the absolute best natural gas plant to the average coal plant? The source also isn't neutral.

>Finally I checked renewables for South Australia and they seems to be doing really great

At the expense of the poor and minorities, which I guess are acceptable collateral damage in this crusade. [1]

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6920209/

Are you just generally writing about green energy, or about the Telsa battery (the subject of this discussion)? As the ancestor comment noted, the battery saved money, and saving money doesn't increase costs.

>You're comparing the absolute best natural gas plant to the average coal plant? The source also isn't neutral.

Source claims comparison is for new plants in both directions. Concur it is likely not neutral, do you have a better one?

> At the expense of the poor and minorities, which I guess are acceptable collateral damage in this crusade. [1]

Disproportional impact of higher energy prices is absolutely a factor... What I do not get is how much better South Australia could have done?

Nat Gas Greenhouse emissions are under reported a lot. The trouble is we do not know by how much. As a person who has spent decades in measuring CO2 my personal guess is 2-3 orders of magnitude. I also both coal and oil emissions are underreported a well.

It is not in people's interest to actually know the correct answer than major changes would be required.

South Australia pricing suffers from a failure of deregulation, not renewable power. The gas/wind/solar mix for generation is fine for a state with a very small population and abundant wind, sun and natural gas. SA has very poor deposits of brown coal which were not sustainable and the country lacks any nuclear power expertise. The state privatised their grid and it is now controlled by foreign owners. Many believe the pricing is the result of gold plating. Generation costs have fallen in recent years and wholesale prices are competitive with the other states.

Batteries are not going to substitute for winterized generation. They are to provide ancillary services such as frequency response (as you mention regarding the Tesla Hornsdale Power Reserve install), previously provided primarily by thermal generators, as well as short term dispatchable discharge (think expensive peaker plants). ERCOT (in Texas) also has a market for generators able to provide black start services (note the grid location of Gambit's install in this article, it sits at the intersection of transmission infrastructure connecting it to thermal generators in the area [1]).

During the rolling blackouts, no attention was paid to avoiding circuits that were powering natural gas compressors and other similar natural gas distribution infra [2] (sidenote: I expect Tesla to do well in battery backing such loads). More distributed battery infra makes the grid more durable, and less at risk for totally black starts [3] [4].

From the city's link to project information [5]:

"Will the battery provide energy to Angelton during a black out or natural disaster?

If charged, the battery can help the local electric system come back online by providing energy to ‘jump start’ electric generators in the. This service is called ‘black start’ capability; the battery is able to help the grid come back online after going ‘black’."

[1] https://openinframap.org/#9.18/29.1828/-95.4064

[2] https://finance.yahoo.com/news/giant-flaw-texas-blackouts-cu... (A Giant Flaw in Texas Blackouts: It Cut Power to Gas Supplies)

[3] https://en.wikipedia.org/wiki/Black_start (A black start is the process of restoring an electric power station or a part of an electric grid to operation without relying on the external electric power transmission network to recover from a total or partial shutdown.)

[4] https://www.texastribune.org/2021/02/18/texas-power-outages-... (Texas was "seconds and minutes" away from catastrophic monthslong blackouts, officials say)

[5] http://angleton.tx.us/DocumentCenter/View/3793/Gambit-Energy...

Smaller gas turbine gensets are far more effective at filling the black start capacity role than batteries are. You don't have to worry that they are charged. They don't really go bad as long as they are stored properly. You can run them on a huge range of fuels. They can be jump started & towed around by light/medium duty trucks if necessary. They produce reliable power for a reasonable duration (days-weeks). With batteries, you don't have much time to screw around before the big turbine needs to be spinning again.

I would argue that a water damn would be a better storage of energy than batteries. Although it can be environmentaly problematic depending where you put it, it can hold an enormous amount if energy which can be switched on in seconds.

Given the discussion about the Australian Tesla battery, worthwhile mentioning that we're also doing a massive pumped hydro project "Snowy Hydro 2.0". 2000 MW, 350 GWh storage. But it's a tad controversial.

[0] https://www.snowyhydro.com.au/snowy-20/about/

[1] https://theconversation.com/snowy-2-0-will-not-produce-nearl...

Thanks for the figures. Can this also alter the economics of Texas' grid ? after all a stabler supply probably means stabler prices, the lack of control worsened the recent crisis I believe.

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