Scientists uncover game-changing innovations that cut solar energy costs

The Evolution of Solar Power: A Story of Innovation and Cost Reduction

Since the 1970s, the price of solar panels has dropped by more than 99 percent. This dramatic decline has transformed a once-expensive technology into a widely adopted power source for millions of homes. As a result, solar energy has significantly reshaped global energy markets.

A recent study conducted by the Massachusetts Institute of Technology (MIT) and published in PLOS ONE has uncovered the reasons behind this remarkable drop in solar power prices. The research highlights the complex network of hidden breakthroughs that have made photovoltaic (PV) systems a major force in achieving net-zero goals.

The findings reveal that decades of innovation, much of it originating from outside the energy sector, have been instrumental in bringing solar power into the mainstream. These insights could also serve as valuable lessons for reducing the costs of other renewable technologies.

A Cascade of Breakthroughs

MIT researchers identified 81 distinct innovations that have contributed to the reduction of PV system costs since 1970. These innovations spanned various aspects of solar technology, including improvements within the panels themselves, such as wire-sawing techniques that allow for slicing large silicon blocks into thin wafers, thereby reducing silicon waste. Systemic improvements, like faster permitting procedures for new projects, also played a significant role.

These breakthroughs were not limited to the solar industry alone. Innovations in fields such as semiconductors, metalworking, glassmaking, and even legal reforms all contributed to driving down costs and enhancing the performance of solar power.

Kostantsa Rangelova, a global electricity analyst at the energy think tank Ember, explains that incremental improvements are most effective when combined with "higher-level mechanisms such as learning-by-doing and economies of scale." This means that as production increases, small gains can be magnified into substantial cost reductions.

"The story of how solar became the cheapest form of electricity in history is one of a steady pace of systemic incremental innovations that brought new materials, tools, and processes, often combining these elements to improve efficiency and reduce costs," she says.

Solar Nears a Tipping Point in Europe

The impact of these long-term cost cuts is now evident in Europe’s power mix. In June, solar power generated more electricity than any other source in the EU for the first time in history. This milestone comes as clean energy investment surges.

Globally, around €1.7 trillion was invested in renewables last year, which is €685 billion more than fossil fuels. Experts suggest that the sector is approaching a positive tipping point, a moment when small changes can catalyze rapid, irreversible growth.

Offshore wind is now 53 percent cheaper than fossil fuels, but solar power’s fall in cost has been the most dramatic. Decades of steady R&D, mass production, and knowledge spillovers from other industries have brought Europe to a point where solar is not only competing against fossil fuels but leading a shift toward renewable sources.

What Still Needs to Change?

For MIT’s researchers, the lesson from solar power’s past is that breakthroughs often come from unexpected places. The next phase of cost reductions could depend as much on processes, policies, and software as on materials and hardware.

AI-driven design tools, robotics for faster installation, and better integration with electricity grid management could deliver fresh savings and quality improvements, according to the authors. Greater computing power is already enabling remote site assessments and automated engineering reviews, which can cut delays and costs.

Rangelova adds that another key lesson from solar power’s sweeping cost reductions is modularity. Designing technologies like solar panels so that they are made of smaller, standardized, and easily reproducible parts allows for more simple and quick manufacturing and installation.

"This is already contributing to rapid cost reductions in battery technologies," she says.

Yet, as the technology advances, other challenges demand attention.

Scientists Are Closing the Recycling Gap

As solar installations soar, attention is turning to end-of-life management. Solar panels are built to last 30 years or more and withstand harsh conditions. However, they are not designed to be easily dismantled for recycling. Their durability makes dismantling them for recycling difficult and expensive, raising concerns about a looming waste problem as early units reach retirement.

Globally, scientists are beginning to address this issue. New research projects, from the EU to Australia, are developing more affordable and sustainable recycling methods, while some companies are designing panels with end-of-life recovery in mind. Repair and reuse are also gaining traction, keeping older panels in service instead of sending them to landfill.

Other renewables face similar hurdles. Although 80-95 percent of wind turbine materials—such as steel, copper, concrete, and even some resins—can already be reused or recycled, scientists estimate that turbine waste could exceed 43 million tonnes by 2050. That makes the rapid adoption of these technologies all the more urgent.

The MIT researchers noted that while most solar panel innovations originated in research labs or by industry titans, many of the systemic innovations that spurred further growth and development were spearheaded by governments. "Through this retrospective analysis, you learn something valuable for future strategy," says Trancik. "It is also useful to know what adjacent sectors may help support improvement in a particular technology."

That means sustaining the conditions that allowed solar power to absorb innovations and ensuring the next leap forward is as impactful as the last.