A new global study from the Boston University Institute for Global Sustainability (IGS) has found that more than 60% of energy infrastructure projects run over budget, with nuclear power posing the highest investment risk and solar energy among the lowest.
As the world prepares to invest over $100 trillion by 2050 to build net-zero energy infrastructure, this research — published in Energy Research & Social Science — provides a sobering analysis: the average project costs 40% more than forecasted and takes nearly two years longer to complete.
The study identified nuclear power plants as the most problematic:
Emerging technologies like hydrogen infrastructure and carbon capture and storage (CCS) also showed significant cost and time overruns. Similarly, natural gas thermal power plants were found to be risk-prone and costly to scale quickly enough to meet climate goals.
“These findings raise a red flag about scaling a hydrogen economy,” said Benjamin Sovacool, lead author and IGS director.
Conversely, solar energy and electricity transmission grid projects consistently outperformed expectations, often being completed under budget or ahead of schedule. Wind farms also performed strongly in both time and cost metrics.
“Wind and solar not only reduce carbon emissions but offer lower construction risk and greater financial certainty,” Sovacool noted.
Researchers evaluated 662 energy projects across 83 countries, totaling $1.358 trillion in investments between 1936 and 2024. Technologies included:
The research uncovered key factors behind cost overruns, including project size, governance, and construction complexity. Notably, energy projects above 1,561 MW capacity experienced significantly higher risk of cost escalation.
“Large-scale projects show diseconomies of scale,” said Hanee Ryu, co-author. “Modular, smaller-scale renewable solutions could be both safer and more cost-effective.”
As governments, developers, and investors strategize for a net-zero future, the findings highlight the importance of scaling low-risk, clean technologies — especially solar and wind — for faster, cheaper, and more reliable energy transitions.