Why fusion energy costs could lag behind solar and wind

Fusion energy costs may fall slower than solar or wind, new study reveals

Fusion Power Could Be a Reliable, Zero-Emission Energy Source—But It May Not Come Cheap

Fusion energy could one day provide a dependable, emissions-free power source. But before that happens, significant hurdles remain: beyond achieving stable technical operations, fusion plants must first be constructed and then brought online. Now, a new study suggests that even if this promising future arrives, it may not be as cost-effective as hoped.

Technologies tend to become cheaper over time. Lithium-ion batteries, for example, now cost about 90% less than they did in 2013. Historically, however, different technologies have followed this cost-reduction curve at varying speeds. When it comes to fusion, its costs may not fall as rapidly as those of batteries or solar power.

Predicting the expenses of a technology that doesn't yet exist is inherently difficult. But with billions of dollars in public and private funding at stake, it's worth carefully assessing the future energy mix—and its potential costs.

A key metric in this analysis is the "experience rate"—the percentage by which the cost of an energy technology drops each time its installed capacity doubles. A higher rate means faster price declines and greater economic benefits from scaling up.

Historically, onshore wind power has seen an experience rate of 12%, lithium-ion batteries 20%, and solar modules 23%. Other energy technologies have improved more slowly—nuclear fission, for instance, sits at just 2%. In the new study, published in Nature Energy, researchers sought to refine predictions about fusion's future costs by estimating its experience rate. The team examined three key factors that may influence this rate: plant size, design complexity, and the need for customization. The larger, more complex, or more specialized a technology is, the lower its experience rate tends to be.

The researchers surveyed fusion experts—including public-sector scientists and private company employees—asking them to evaluate fusion plants based on these criteria. Using their responses, the team projected the experience rate, focusing exclusively on two leading approaches: magnetic confinement and laser inertial confinement, which together account for the majority of current funding. Other fusion methods may yield different cost-benefit profiles.

Given these findings, it may be time to reassess the current level of investment in fusion energy. In fiscal year 2024, the U.S. allocated over $1 billion to fusion research, while private-sector funding between July 2024 and July 2025 reached $2.2 billion. Europe and Germany are also determined to stay competitive in the race for fusion power. Under its Fusion Action Plan, the German government aims to build the world's first operational fusion plant in the country. Startups like Marvel Fusion and Proxima Fusion are contributing to this push, with more than €2 billion earmarked for fusion research by 2029.