Hacker News Reader

Again this assumes fusion power will be cheap. But in reality it may cost about as much as (fission) nuclear power. So yes it may help with making energy production carbon-free (together with solar, wind, hydro), but it won't necessarily create a some sort of energy abundance.

View on HN

The theory isn't that the cost will be low, it's that the output will be high. If it costs the same amount as a fission reactor but produces ten times more power, that's lower cost per MW than anything on the market. Even if it costs more than fission, it could be competitive as long as the more it costs is less than the more it outputs.

But how should that gain in energy output be possible without making the whole system huge, too? The heat generating part of a nuclear power station only makes up a small fraction, most of the material is for transforming the heat to electricity and to shield off radiation. If you want to process more heat, you need more infrastructure to do so.

But why would a fusion reactor produce 10 times more power than a fission reactor of the same cost? A fission reactor is, comparatively, very simple. Just a steel cylinder filled with fuel and control rods. No superconducting magnets, no zillion degree plasma to contain and control, low neutron field (as long as we're comparing to D-T fusion). Also heat transfer is much more efficient, enabling high power density, since you pump coolant through the entire reactor vessel instead of just the outer edges.

Reply on news.ycombinator.com