Unless fusion power is dramatically more efficient than other thermal plants, like 99.9%, your bigger plant will still need massive heat removal structures and systems, which means siting them near water. All the good spots are already taken.
Alternatively you can use truly massive air heat transfer structures, driving up your construction costs again.
I neglected to mention finance costs also. With an untried technology the rate of return demanded is going to be very high, further driving up project costs.
A major cost of the most utilized existing power plants (coal and natural gas) is fuel. If you build a natural gas plant which is twice as big so that you can put it out where the land is cheaper and eat the transmission losses, now you need twice as much natural gas.
Renewables don't need fuel but their construction cost is fully linear, you get no economies of scale. If you want twice as many solar panels then you need twice as much land. If you want to double the size of your fusion reactor, you build an eight story building instead of a four story building on the same piece of land.
> Unless fusion power is dramatically more efficient than other thermal plants, like 99.9%, your bigger plant will still need massive heat removal structures and systems, which means siting them near water. All the good spots are already taken.
An obvious solution is to build them out in the ocean. Then you have plenty of water and you're still not near anything.
And the good spots near population centers are already taken. Some lake a hundred miles from any city won't be.
> I neglected to mention finance costs also. With an untried technology the rate of return demanded is going to be very high, further driving up project costs.
That's only true for the first one. If it's hypothetically ten times more power for the same money, that'll get one built even at a high interest rate. Then once you have it running it's proven technology.
Coal is dead. The competition is PV, and to a lesser extent wind.
> Renewables don't need fuel but their construction cost is fully linear, you get no economies of scale. If you want twice as many solar panels then you need twice as much land.
Yes, and you use odd bits of land close to consumption sites, many of which will have simultaneous use for other purposes. Edit: the linearity is an advantage in that it enables mass production, and gets the benefit of the manufacturing learning curve. So your suggestion of overbuilding on cheap land a long way away from cities applies even more to PV.
> If you want to double the size of your fusion reactor, you build an eight story building instead of a four story building on the same piece of land.
Quadrupling your construction costs. Edit: mainly in the finance cost of the time taken.
Also, making your generators much bigger than current practise increases project risk and therfore cost.
> An obvious solution is to build them out in the ocean.
Quadrupling your construction costs again, and decreasing reliability, capacity factor and productive lifetime. Seawater is nasty stuff.
> And the good spots near population centers are already taken. Some big lake a hundred miles from any city won't be.
It will be used for productive farmland, though. Again, why aren't fission or CCGT plants being built in those places? How is fusion different?
> [High finance cost is] only true for the first one. If it's hypothetically ten times more power for the same money, that'll get one built even at a high interest rate. Then once you have it running it's proven technology.
It's about time to cashflow for utility finance types, and they also tend to want a longer track record than "it worked once". The linearity/modularity of wind and PV is an advantage in the time to cashflow aspect.
Edit: I haven't so far seen anything significant in your replies that doesn't also apply to fission. Utilty project financiers are hard-headed; they'll finance fission if it makes them enough money soon enough.
You are fiddling around the edges rather than demonstrating an order of magnitude cost reduction from PV.
Coal is dying but it's still ~20% of US generation. The natural gas share of US generation has gone up.
> Yes, and you use odd bits of land close to consumption sites, many of which will have simultaneous use for other purposes.
Until you run out of those and then your costs increase worse than linearly because you have to start using more expensive land.
> the linearity is an advantage in that it enables mass production, and gets the benefit of the manufacturing learning curve.
Anything you're going to use for a large fraction of the power grid is going to be mass produced.
> Quadrupling your construction costs.
This is the opposite of how economies of scale work. If you make something bigger, the variable costs scale linearly and the fixed costs stay the same but are amortized over more units.
> Also, making your generators much bigger than current practise increases project risk and therfore cost.
This is no different than needing twice as many turbines to generate twice as much power. It's a variable cost, offset by you getting twice as much power without increasing your fixed costs.
> Quadrupling your construction costs again, and decreasing reliability, capacity factor and productive lifetime.
You keep saying "quadrupling your construction costs" without evidence. We build oil platforms in the ocean on a regular basis. They cost some tens of millions of dollars. Existing fission reactors cost some billions of dollars. The difference from being on the ocean is evidently not the dominant cost. And then you don't have to pay for land.
> Seawater is nasty stuff.
Many existing reactors are situated on coastlines and cooled by seawater. It's not some kind of insurmountable problem.
> It will be used for productive farmland, though.
The price of "productive farmland" compared to the price of land near a city is multiple orders of magnitude less, and high density power generation doesn't need that much land.
> Again, why aren't fission or CCGT plants being built in those places? How is fusion different?
New fission reactors largely aren't being built at all because of regulatory suppression. CCGT plants can't afford to spend fuel generating power which is then lost to long distance transmission.
> It's about time to cashflow for utility finance types, and they also tend to want a longer track record than "it worked once".
If it worked once but is now generating ten times more power per unit of investment capital than any of the alternatives then investors would be lining up, and may not even be needed because the plant operator could use revenues from selling such a large amount of electricity to build more plants with.
