- Average energy projects cost 40% more and take nearly two years longer to build than planned.
- Nuclear power plants have the highest investment risk with average cost overruns of 102.5%, adding $1.56 billion extra.
- Solar and grid transmission projects perform best, often finishing under budget or ahead of schedule.
- Hydrogen, carbon capture, and natural gas thermal plants show significant overruns, raising scalability concerns.
- Wind farms also show favorable financial risk with lower construction delays.
- Large projects over 1,561 MW face higher cost escalation risks, suggesting benefits of smaller, modular approaches.
- Study analyzed 662 projects across 83 countries from 1936 to 2024, totaling $1.358 trillion in investment.