3 ms·

> when the energy is basically free, you don’t have to try too hard to capture the output to make something of it. Is that actually the case with harvesting fus

> when the energy is basically free, you don’t have to try too hard to capture the output to make something of it. Is that actually the case with harvesting fusion energy? We still haven't got more usable energy (electricity and/or heat) out of a fusion reactor than it takes to run the thing, so capturing as much of the energy as possible is still absolutely important. However, in the long-term (e.g. 100 years from now) you're right that working fusion power plants would make energy "basically free". The main reasons would be (a) the abundance of fuel (assuming the source would be heavy water) and (b) the fact that nuclear reactions are so much more energetic than the chemical reactions we're used to (so even a few percent improvement may be a large amount of extra energy).

hobscoop 5y ago
It's not plausible that even fusion power plants would make energy 'basically free'. 1) Fusion plants still require site infrastructure, power conversion technology, waste heat removal, and (though not for this particular concept) steam generators (or other fluid cycle generators). These have significant capital costs but finite lifetimes. You're right that the variable cost of energy is pretty low, probably comparable to current fission plants, but that's still more expensive than the variable cost of electricity from solar and wind. 2) The price of electrical transmission and distribution starts to become important (I forget what the typical cost of that today is, but it's a few cents/kWh.) This doesn't matter if you can put a small power plant at your local industrial park though. 3) There's a big difference between $0.05/kWh, $0.02/kWh, $0.01/kWh, and $0.005/kWh, and then a huge difference to 'true zero'. This is because there's probably lots of industrial processes that we might like to do if electricity and heat were cheaper than it is today, each becoming reasonable at a certain price. There could be a large market at each price floor 'step'. 4) Yeah, the fuel is abundant, which is good, but fuel costs are not significant drivers of the cost of fission. While not free, I'd like to think that fusion will help make a world with energy much cheaper than the world without fusion.

hobscoop 5y ago

It's not plausible that even fusion power plants would make energy 'basically free'. 1) Fusion plants still require site infrastructure, power conversion technology, waste heat removal, and (though not for this particular concept) steam generators (or other fluid cycle generators). These have significant capital costs but finite lifetimes. You're right that the variable cost of energy is pretty low, probably comparable to current fission plants, but that's still more expensive than the variable cost of electricity from solar and wind. 2) The price of electrical transmission and distribution starts to become important (I forget what the typical cost of that today is, but it's a few cents/kWh.) This doesn't matter if you can put a small power plant at your local industrial park though. 3) There's a big difference between $0.05/kWh, $0.02/kWh, $0.01/kWh, and $0.005/kWh, and then a huge difference to 'true zero'. This is because there's probably lots of industrial processes that we might like to do if electricity and heat were cheaper than it is today, each becoming reasonable at a certain price. There could be a large market at each price floor 'step'. 4) Yeah, the fuel is abundant, which is good, but fuel costs are not significant drivers of the cost of fission. While not free, I'd like to think that fusion will help make a world with energy much cheaper than the world without fusion.