Energy · Photovoltaic Cost

Solar PV Cost

Solar modules fell about 500-fold in real terms, and reversed more than once on the way down.

• $132/W → $0.27/W, 1975–2024
• Swanson’s Law: ~20% per doubling
• 2005–08 and 2022 reversals are real
• 2025’s $0.09/W spot price isn’t shown

The price of a solar module per watt of capacity fell roughly 500-fold, from $132 in 1975, when photovoltaics were mainly a spacecraft technology, to $0.27 in 2024. Every figure is in constant 2025 dollars, so none of the fall is inflation. The series is published by Our World in Data and built on Nemet’s and Farmer and Lafond’s historical reconstructions. OWID’s own metadata says it uses global estimates before 2010 and European market benchmark prices thereafter, so the line is a disclosed composite, not one global average. It follows Swanson’s Law: module prices drop about 20% for every doubling of cumulative production, driven by better polysilicon, larger wafers, and Chinese manufacturing scaling from megawatts to terawatts. The fall reversed more than once, and the reversals are real. The sharpest was the mid-2000s polysilicon shortage, when demand outran the supply of purified silicon and prices climbed for three years; prices ticked up again in 2022 under pandemic-era supply strains. The line ends in 2024 because that is where OWID’s inflation-adjusted data ends. The cheaper headline figures in circulation, around $0.09 a watt in 2025, are nominal ex-factory spot prices for Chinese TOPCon modules, a narrower measure, and supply-side policy in China pushed them back up toward $0.11 through 2026. They are not plotted, because a nominal spot price cannot be spliced into an inflation-adjusted global-average series without breaking its basis.

Source: IRENA / Nemet / Farmer & Lafond, via Our World in Data

Download the data: solar_cost.csv · solar_cost.json

All curves · The chart is drawn in your browser and needs JavaScript. Every number it plots is in the table above.