Fusion's cost floor: what if the core were free?
9 hours ago
- #Fusion Energy Economics
- #Cost Analysis
- #Alternative Fuels
- If the core of a fusion plant were free, total electricity costs would be around $29/MWh for Deuterium-Tritium (D-T) fuel, which is nearly three times the target of $10/MWh (1 cent per kWh). The fusion core itself accounts for about two-thirds of a fully costed D-T plant's levelized cost of electricity.
- Building and staffing costs, especially for D-T plants, are major factors: D-T requires heavy shielding, tritium containment, and around 78 full-time employees, totaling $570 million for buildings alone. This structural burden exists regardless of core costs.
- Reaching the $10/MWh target is extremely difficult for D-T, even under aggressive conditions like 5 GWe scale and favorable financing, as it leaves little to no budget for the fusion core. Automation could halve staffing to roughly 40 FTE, but margins remain razor-thin.
- Fuel choice fundamentally impacts the cost floor: Aneutronic fuels like proton-boron (p-B11) reduce building costs to $354 million, require only standard staffing, and cut the floor to $18/MWh, closer to the target than D-T.
- Balancing scale, availability, financing, and construction time is critical. For instance, at 2 GWe, p-B11 can achieve an $8/MWh floor, leaving $2.4/MWh for the fusion core with a budget of roughly $920/kW, which is challenging compared to mature power plants.
- Direct energy conversion could bypass thermal cycles and further lower costs for aneutronic fuels, potentially reshaping the economic floor, though it's less mature and uncertain than traditional methods.
- Reaching ultra-low-cost fusion is not just a core physics challenge; it requires whole-plant optimization, including large scale, high availability, low-cost financing, and fuels that minimize radiation-related expenses.