Byd Unveils World's Largest 14.5 Mwh DC Energy Storage System

Posted4 months agoActive4 months ago

philipkglass

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23 comments

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Energy Storage

Renewable Energy

Grid Technology

BYD has unveiled the world's largest 14.5 MWh DC energy storage system, sparking discussion on its potential applications in grid stability and peak shaving at the local level.

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Discussion (23 comments)

Showing 23 comments

philipkglassAuthor

4 months ago

4 replies

The most interesting thing is the low levelized cost of storage offered by this new unit:

At the heart of HaoHan is BYD’s self-developed 2,710 Ah Blade Battery cell, which the company claims is the largest energy storage cell in the world. This next-generation cell delivers three times the capacity of conventional storage batteries, boasts a cycle life of over 10,000 cycles, and reduces the total lifecycle cost per kilowatt-hour to below CNY 0.1 ($0.014) – a milestone that could reshape the economics of large-scale storage.

At 1.4 cents per kilowatt hour to store, that actually puts storage cost below generation cost for solar power. In sunny regions solar without storage has been cheaper than fossil generation for a few years now, but with batteries like these it's going to be cheaper than fossils for overnight usage too.

The other exciting thing is that while this is a Chinese product, we can expect similar cost drops outside of China over time. Today's non-Chinese solar cells are about where Chinese solar cell prices were 5-9 years ago. China gets the low prices first, but global manufacturing costs keep dropping too because the lower costs are driven more by technological improvements than by China-specific factors like inexpensive labor or lax environmental standards.

toomuchtodo

4 months ago

1 reply

These prices keep falling faster than the graphs can get updated, which is quite humorous imho.

https://ourworldindata.org/battery-price-decline

https://ourworldindata.org/grapher/average-battery-cell-pric...

https://rmi.org/the-rise-of-batteries-in-six-charts-and-not-...

https://docs.nrel.gov/docs/fy25osti/93281.pdf

https://about.bnef.com/insights/commodities/lithium-ion-batt...

actionfromafar

4 months ago

2 replies

Ah, but you see, battery storage is ackshully impossible, we must have nukular, clean, beautiful coal instead of golf course destroying wind mills and solar.

karmakurtisaani

4 months ago

1 reply

I see you've visited an energy discussion thread on HN before.

actionfromafar

4 months ago

Thought I'd save three commenters the trouble. Although now we are kind of spoiling that.

tim333

4 months ago

1 reply

But nuclear is cheap and easy! Look at our Hinkley C, announced 2010, maybe operational 2030 and only £45bn! How are batteries going to compete?

actionfromafar

4 months ago

I wonder what 45bn of batteries would get us. I imagine a lot of batteries.

torginus

4 months ago

2 replies

Using the 3.7V nominal voltage for a lithium cell, that puts the Blade Battery at 10kWh - I think the price provided is for over the entire life of the battery which works out to 10000x10kWh*$0.014/10kWh, which is $140 per kWh. Not expensive, but not particularly remarkable considering modern pack prices.

onraglanroad

4 months ago

1 reply

That calculation doesn't make any sense. I mean you both multiply and divide by 10kWh, so those cancel out and you end up with just $ (not "per" anything).

What's that supposed to be the price of?

I guess if you have 10,000 cycles and one kWh costs $0.014, then that's just the cost of 10,000 kWh.

torginus

4 months ago

1 reply

I calculated the cost of the pack from the data at $140 for 1kWh. I guess I shouldn't have included the kWh in the divisor but

(10000x3.7V2710Ah$0.014) <- total cost of the pack

10 <- normalize to 1kWh

$140

mchusma

4 months ago

This makes more sense than battery costs dropping 99%. I was confused by op, and wish it were true. It’s more like 10x solar than 1/10th solar.

abdullahkhalids

4 months ago

1 reply

Another grid-scale Chinese battery got bids for ~US$66 last year [1]. So this is twice as expected but maybe the other battery won't have as many cycles.

[1] https://reneweconomy.com.au/mind-blowing-battery-cell-prices...

toomuchtodo

4 months ago

1 reply

A recent (July 2025) winning bid was $US51.59/kWh.

https://reneweconomy.com.au/watershed-moment-big-battery-sto...

> The latest auction in China offered 25 gigawatt hours of capacity for lithium iron phosphate (LFP) batteries over a range of storage periods – 1 hour, 2 hour and 4 hours – and the results (the first time they have been broken down on storage duration) have stunned even seasoned onlookers. The knockout price was a bid of $US51.59/kWh for a four hour battery (the average was $US59/kWh), which Energy Storage News says represents a 30 per cent drop from 2024 levels, and others side was a 15 per cent fall from recent record lows.

It would be exciting if the price continues to decline 15-30 percent per year. Unsure if that’s sustainable at current manufacturing and learning rates, but exciting.

Tepix

4 months ago

1 reply

Aren‘t we close to getting much cheaper batteries with Sodium? https://www.geeky-gadgets.com/catl-sodium-ion-battery-packs/

abdullahkhalids

4 months ago

1 reply

There are always tall claims. The only real check on claimed prices is when the product is sold on the market. So wait for installations on this one too.

toomuchtodo

4 months ago

Some pricing within this article on large scale sodium ion grid forming battery storage in China.

https://www.ess-news.com/2025/06/03/china-launches-worlds-fi...

whitehexagon

4 months ago

>but with batteries like these it's going to be cheaper than fossils for overnight usage too.

1200eur bought me a reasonable LiPo solar 'buffer battery' for evenings, and ROI is maybe 3 years vs buying fosil fuel electrons at peak tarif. Plus savings from being able to drop the fixed ~70% of my bill grid connection charge.

Anyway, exciting to see that I might soon be able to afford enough storage for cloudy days too. Thanks for the extra details, sounds too good to be true.

tim333

4 months ago

That's cool. As a consumer I'm paying ~30 cents per kWh so there would seem to be a lot of room for that sort of thing to reduce prices. I'm in the UK where prices just seem to go up regardless of tech but maybe there's hope.

applied_heat

4 months ago

2 replies

>Beyond raw performance, the GC Flux PCS features advanced grid-forming capabilities, making it ideal for modern grid applications. It supports active inertia response up to 25 seconds, wide-band damping across 1–1500 Hz, and ultra-fast voltage and frequency regulation in under 100 milliseconds

I wonder what active inertia response is and why it is limited to 25 seconds.

The normal rotating machines have inertia, stored rotational kinetic energy, so when electrical load is added and mechanical power in does not immediately change they new load is fed by the generator very slightly Slowing down and measured by a decreasing frequency.

How would active inertia be different from the inverter simply putting out more power when frequency drops?

skewbone

4 months ago

1 reply

People tend to use the inertia H constant (MW*s/MVA) when it comes to describing the amount of inertia that grid forming inverters and batteries can provide. Sometimes the units are simplified to seconds, which makes it easier to understand how many seconds it could provide rated power for this specific function.

Active inertia or synthetic inertia do vary power when frequency changes but the key is the dynamic behavior. They typically do so by emulating a synchronous machine by implementing something like the swing equation in the active power control (see REGFM_B1 [1]). They essentially emulate the inertia, which makes them have some damping in changing the phase angle and frequency of their voltage waveform just like a spinning synchronous generator would when resisting frequency changes due to physical inertia, resulting in an inertial active power response. This makes it easier for people to analyze because they understand the swing equation from synchronous generators.

[1] https://docs.nrel.gov/docs/fy24osti/90260.pdf

applied_heat

4 months ago

Thanks for the reply and the link.

A machine with infinite inertia would resist any frequency change and instantly go to maximum or minimum power upon any grid frequency deviation.

A 25s inertia constant is impressive. The hydro units I work on are anywhere from 1s for newer units to 7s for older ones intended to run isolated networks. And then the ease of frequency regulation on the unit is dictated by the inertia of the water in the water conveyance system “water starting time”

So 25s inertia constant would appear to be a response to frequency change much faster and greater than the typical 5% droop implemented by the governors controlling mechanical power applied to the shaft.

Wild stuff!

zipy124

4 months ago

Outputting more power when frequency drops is exactly what their active inertia system does, its a feature of the inverter/ battery EMS system. I think there was a communication issue between engineering and the marketing/PR team, as there often is in large companies.

nerpderp82

4 months ago

Awesome article!

Since these are so small, we could augment the last neighborhood level transformers with these and upgrade the local grid. Home solar could charge into these, we really could do peak shaving at the local level.

The other use would be for data centers to buy when power is cheap and shave their peaks as well.

I am very bullish on utility scale batteries.

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