50 years of solar panel efficiency evolution (1970-2026)

Solar panel efficiency is the percentage of light it converts to electricity. In 50 years we've tripled that figure. The progress curve is one of the cleanest in any industry.

1970: 8% commercial, 14% lab

Start of post-Bell Labs era. Single-crystal silicon barely improved. Artisanal manufacturing. Application: military and space only. Cost $100/W. Not viable for mass terrestrial use.

1980: 12% commercial, 17% lab

Better silicon purity and doping. Polycrystalline appears, cheaper. First US residential installs (Carter program). Cost drops to $20/W.

1990: 15% commercial, 22% lab

Multijunction cells (stacked materials) appear in lab. Record 24% in pure silicon. Commercial stuck at 15% (production bottleneck). Cost $8/W.

2000-2010: 17% commercial, 24% lab

Chinese production takes off. Brutal learning curve. Continuous gradual improvement, no jumps. Back-contact (SunPower) emerges. PERC appears in research. Cost $3/W by end of period.

2010-2020: 20% commercial, 26% lab

PERC goes mass-market. Commercial efficiency rises 1%/year. Lab record 26.7% (Kaneka, 2017) on silicon HJT. Cost crashes to $0.50/W. Solar becomes cheaper than coal in many countries.

2020-2026: 23% commercial, 26.6% lab

TOPCon replaces PERC. HJT grows. Tandem perovskite-silicon emerges in lab (record 33.9% in 2024). Commercial capped by Shockley-Queisser 29% limit for pure silicon. Cost $0.30/W.

2026-2030: commercial tandem perovskite

First tandem perovskite-silicon cells in commercial production. Target: 28-30% commercial in 2027. Will break pure silicon's theoretical limit and trigger new wave of installed-cost reduction.

Compare with perovskite: the future.