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The Solar Century: How Green Energy Prices Have Tumbled
By Will Coulman
Vanguard Satellite with solar panels
The 10,000-fold decline in the cost of solar cells is upending the global energy mix
Call it the solar century.
As recently as the 1990s, solar energy was seen as a prohibitively expensive alternative to fossil fuels. What happened next defied almost all expectations.
One of the earliest uses of silicon solar photovoltaic (PV) power was in the Vanguard I satellite in 1958. It cost an astonishing $3,064 per watt to build, adjusted to 2025 prices. Today, one watt of solar costs only around $0.30. That’s over a 10,000-fold reduction.
Jimmy Carter puts solar panels on the White House
Sharp Corporation in Japan began mass-producing solar panels for consumer use
This precipitous decline in prices is driving investments on the ground. Renewables accounted for nearly nine out of 10 new power generation projects globally last year, according to data from the International Renewable Energy Agency.
Solar installations are doubling every three years, growing tenfold each decade, reporting from The Economist shows. A greener future is quietly arriving.
Every time the total installed capacity of solar doubled, costs fell by a consistent percentage, a trend that’s become known as Swanson’s Law. This pattern has held for over 40 years, a rare and remarkable phenomenon in the world of technology.
German Renewable Energy Act (EEG)
China's Solar Manufacturing Scale-Up
$.per watt
Why is solar getting cheaper to produce?
Solar’s price decline has been driven by innovations across every panel component.
Silicon wafers were made thinner.
Cell structures were optimized to capture more sunlight.
Production shifted from artisan assembly to industrial-scale automation.
Beyond the panels, other essential parts of solar energy systems have also improved with time.
Mounting systems became easier to install, installation techniques improved and permitting processes were streamlined. These “soft costs” fell alongside hardware prices, making complete solar systems increasingly attractive.
Solar photovoltaic (PV) prices have fallen faster than other energy sources
Solar energyWind energy
Source: International Renewable Energy Agency
Solar hasn’t been the only source of renewable energy to decline in cost. Wind energy has also become more affordable as turbines have become taller and more efficient, placement strategies have improved, and competition has brought construction costs down.
However, building a wind turbine remains more like building a high-performance vehicle: complex, quality-focused and less suited to mass production. Solar cells, by contrast, became a commodity – and that made all the difference.
The key parts of a solar cell and how the prices of each part have declined over time
Source: National Renewable Energy Laboratory
As prices dropped, adoption surged. As more people bought solar, manufacturers scaled up production. As production increased, prices fell even further. This virtuous cycle transformed solar from a niche alternative into an economic no-brainer.
The turning point came when unsubsidized solar began to beat coal and gas on cost. In many markets today, solar provides the cheapest electricity available—without a cent of government support.
Solar's affordability opened new possibilities. Community solar programs now allow apartment dwellers and renters to benefit from solar savings. Subscription models eliminate upfront costs. What was once accessible only to wealthy homeowners is becoming available to everyone.
The solar century may have some way to run yet.
On the topic ofInfrastructure
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