The greatest problem with fusion power is rarely mentioned and scarcely on the research agenda: capital cost. When I discussed the problem earlier, in “Fusion Power: A New Way to Boil Water”, I hadn’t seen this quietly damning report, which I think is worth quoting:
From the introduction:
The goal of this activity is to provide guidance to the fusion energy sciences community based on industry requirements…
Buried among the discussions of plasma physics, neutron fluxes, and a host of practical engineering concerns, there is a page that briefly notes the “Achilles’ Heel” that makes the rest look like an academic exercise. There is no mention of the problem in the introduction or the conclusions:
From page 22:
Fusion fuel is cheap, but the capital costs are high. This may be the Achilles Heel of economic fusion power. The capital costs must be lowered by significant amounts — an order of magnitude of cost reduction would be highly desirable but probably not attainable. Traditional cost cutting efforts offer marginal improvements and will not be sufficiently effective. Innovative approaches that promise orders of magnitude cost reductions on major items must be aggressively pursued… [This will require] new fabrication and production technologies….
Translation: There is no known way to build a remotely economical fusion power plant, even if the fuel is free and the plasma physics works perfectly.
The report speaks of potential, unspecified, orders-of-magnitude reductions in fabrication cost, but what would other technologies look like if evaluated by the same rules?
Advances that would drop the cost of future fusion power machines into a range competitive with current photovoltaic devices are on a scale that would drop the cost of future photovoltaic devices to almost nothing.
(The above all refers to the leading proposal for fusion power, the tokamak approach. I haven’t seen an analysis in similar depth of the competitors.)
As I showed before, here’s the planned ITER reactor, including the high-vacuum chamber and its surrounding high-field superconducting magnets, together with the requisite particle accelerators, power systems, etc.,. Ordinary nuclear reactors are mostly plumbing; this is a fancy physics apparatus, more nearly comparable to the Large Hadron Collider.
For scale, note the person in the blue coat standing at the bottom:
The plasma physics problems are a fascinating distraction from the physics of advanced fabrication. (This would, admittedly, solve the cost problem.)
- The Physical Basis of High-Throughput Atomically Precise Manufacturing
- Fusion Power: A New Way to Boil Water