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.