Hacker News Reader

Comment by nuclearnice3 | Hacker News Reader

Here's a more optimistic take especially with regard to solar.

> There’s really no end in sight yet for improvements in solar and batteries. Cost drops are continuing simply from scaling up, and new materials and technologies are on the horizon that could generate continued price declines per unit of energy.

https://noahpinion.substack.com/p/answering-the-techno-pessi...

View on HN

Battery electrochemistry still has headroom, but solar is already approaching the Shockley–Queisser ceiling, which limits efficiency at about 30% for single junction and 50% for multiple junction devices. That's the absolute conversion limit, similar to the Carnot limit for thermal engines.

So if you can buy today cells that are 18-20% efficient, you should not expect dramatic improvements in the next decades, only very gradual. The cost will continue to drop, so given the huge areas available for solar, the potential is still huge.

The Shockley–Queisser ceiling describes the limit of energy per unit area. It says nothing about the efficiency in terms of energy per unit money.

Manufacturing (and installation, operations, and maintenance) efficiencies are more likely governed by Wright's Law, a/k/a Experience Curve Effects, which holds that there is about a 20% efficiency gain with each doubling of output.

<https://en.wikipedia.org/wiki/Experience_curve_effects>

This was first observed during WWII in aircraft and ship manufacture.

Note that this tends to be gains toward some ultimate efficiency limit, so remains bounded.

I've mentioned the concept a few times in earlier HN comments: <https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...>

50% is near to the current lab demonstrated limits for multi-junction, the theoretical max (with infinite layers) is around 88%

Reply on news.ycombinator.com