Reply To: Global Warming

[zapkitty]

asymmetric_implosion wrote:

a_s;
“probably thermal cycle (same old same old).” Not a watt, unless you count such possible applications as heating nearby buildings with warm air, etc. The ancillary equipment to extract heat and convert it to electricity is not a) present, b) economic, or c) usable with the low-grade (low-temp) output of the FoFu.

As for the photovoltaic “inefficiency”, examine the “onion” design. It has perhaps thousands of layers/stages to extract a very high percentage of the X-ray energy.

And as with Z-pinches, sacrificing wires or metal cylinders or pellets etc. with every shot is, IMO, a complexity bridge way too far for continuous output. Murphy’s power grows exponentially with number of components.

Low temp? I’ve seen numbers of 1000C floating around this site. That is a pretty good temperature for a thermal cycle with modest efficiency (~40%).

errr…. no. That’s way too close to the melting point of beryllium at 1278 °C.

A variety of estimates for cooling systems have them handling temps of ~400 to ~600 some odd °C.

My dream would be for tests to find that the core can run at 700 °C without excessive wear… because that would make spacecraft fusion radiator arrays a lot smaller.

But the temps foreseen are no good for any type of efficient steam turbine.

asymmetric_implosion wrote: I’ve looked at the onion. It will absorb x-rays but how much will turn into useful electrons? That is where the efficiency typically comes in. You can absorb 100% of the sunlight but only about 10% is converted to useful electrons. X-rays may convert more efficiently as they are well above the band gap but you are still limited on efficiency.

Yes, estimates are that we’ll just have to live with about… 80% efficiency. It’s a tough burden to bear but someone has to do it.

asymmetric_implosion wrote: I hope it is greater than 40%. I know heat will be generated by a FoFu power plant so the question is why not use it? Turbines on the 5 MW scale are small and efficient.

Actually, they are inefficient at FF temps and are expensive to boot. The major cost of any current thermal power plant is the turbines and their maintenance.

If FF pans out then it will be cheaper and more efficient to simply add another FF unit than it would be to add and maintain an expensive turbine and all of its auxiliary gear and costs.

asymmetric_implosion wrote: A helium turbine in particular is very compact and efficient.

… and [em]very[/em] expensive.

asymmetric_implosion wrote: It adds more electrons to the grid.

You can get more power quicker and cheaper by adding another FF core.

asymmetric_implosion wrote: Some cooling is going to be required of FoFu-1 so why not put that heat to good use rather than dump it into the air needlessly.

Needlessly? Who would do that? No one here, that’s for sure 🙂

Industry uses vast amounts of heat for a vast number of processes and some processes need cooling as well. Buildings and, indeed, entire communities need heating and cooling.

Locally distributed FF units can provide both heating and cooling (via heat-powered absorption chiller systems.)

Simply substituting FF units for fossil power sources [em]lowers[/em] total industrial and habitation waste heat.