Soft paywall.

Wright’s Law (more generally) https://en.wikipedia.org/wiki/Experience_curve_effects

Frith’s group puts the battery cost decline at 18% per production doubling at the pack level. As an example, from 2010 to 2015, lithium-ion battery capacity doubled seven times, from 0.48 gigawatt-hours to 62 GWh. The average price of batteries at the pack level plunged from $1,194 per kilowatt hour to $384. Strictly speaking, the 18% rule should have taken prices down to about $261 ($384 is about what Wright’s Law calls for with six doublings). But it was still a roughly two-thirds plummet.

From 2015 to 2020, battery capacity grew 2.7 times and the price again plunged by two-thirds, to an average of $137/kWh. That overshot the 18% rule, by which the price should have dropped only to about $213/kWh. But if you had strictly tracked the 18% rule from 2010 to 2020, the price ended up right around where it should have been.

Now, BNEF is using the rule to project what happens next. Following Wright, battery prices should drop to $84 per kWh in 2025, well below the holy grail milestone of $100/kWh. In 2030, they should be an astonishing $58/kWh, and $45 in 2035. The price movements in the 2030s seem dramatic, but they are less so than the prior two decades, namely because it will be harder and harder to double total capacity, Frith said.

Assuming no breakthrough in battery materials, there’s still a somewhat predictable price drop. What are the side effects that you see?