Bob Higgins <[email protected]> wrote: When you say that "Cold Fusion at 300C would be fine for automobiles ...", > you have to take into account the fact that the 300C is the loaded > temperature of the system. In RF technology, it is commonly known that to > get maximum transfer of power from a real source having a real source > impedance (in a linear system) . . . >
I do not think the temperature gap is so large in a conventional fission reactor. I looked into this when I was making the video. I cannot find the exact numbers, but briefly: Fission reactor water temperatures inside the reactor reach 345°C. http://www.world-nuclear.org/info/Nuclear-Fuel-Cycle/Power-Reactors/Nuclear-Power-Reactors/ The uranium oxide pellets and the zirconium rods themselves cannot get much hotter than this. I was surprised to find they are damaged at temperatures above 450°C, I think it was. In other words, operators run them about as close to the margin as they can. The pressurized water is not much cooler than the pellets themselves. Fission reactors have poor Carnot efficiency compared to other types. They are about 30% as I recall, whereas combined cycle generators are at 60% or better. Fission reactors are optimized for long life in the low wear-and-tear. They sacrifice Carnot efficiency for this. They can do that because uranium fuel is very cheap per joule of heat. Obviously with cold fusion you can sacrifice all the Carnot efficiency you like, because the fuel costs nothing. You could even make them 5% efficient like an old-fashioned coal-fired steam engine or an automobile in 1960. The only problem is the motor would then be very large and bulky, and the car needs a big radiator. This is why car motors used to be so big. You don't need a fuel tank, so you can take up that space with the motor. I suppose something like a steam turbine with a condenser, where the water is around 300°C, would be suitable for ground vehicle transportation, and for marine engines. It would be like a miniature version of today's fission reactors, hopefully without any radioactive waste. Perhaps a little tritium which I hope can be contained completely. > So, in any practical LENR system, the fuel temperature will be much higher > than the actual operating temperature of the working fluid (maybe twice as > high). > Not if it resembles a fission reactor, as I said. Of course it will be terribly inefficient, bulky and heavy compared to the most efficient engines today. This is another reason why aerospace engines are a distant prospect. A combined cycle electric power generator is called an "aeroderivative" engine because it is a gas turbine based on jet aircraft engine designs. These are optimized for high Carnot efficiency. These generators cost tons of money, but over the life of the equipment they save a huge amount of fuel so they are cost-effective. Expensive gas fuel calls for high efficiency; cheap uranium fuel calls for low efficiency but a long service life. Cold fusion will obviously fall at the fission end of this trade off. In fact, it will go far beyond fission, trading off efficiency for an even lower equipment costs than you can justify with any other energy source. Here is information on the capital costs of various generators: http://www.eia.gov/forecasts/capitalcost/ In the Excel tables on this page, I do not know what "Overnight Capital Cost" means but apparently it is a good way to compare costs. It is defined here: http://www.eia.gov/forecasts/capitalcost/pdf/updated_capcost.pdf It includes all kinds of costs normalized against the generator capacity, which is usually measured in kilowatts. These costs include "Civil and structural costs: allowance for site preparation, drainage, the installation of underground utilities, structural steel supply, and construction of buildings on the site . . . Mechanical equipment supply and installation . . ." blah, blah, etc. You get the picture. "O&M" means operation and maintenance. Anyway, in Table 1 you can compare the overnight capital costs per kilowatt of capacity for various sources: Advanced natural gas, $2,095 Nuclear, $5,530 Onshore wind power, $2,213 Photovoltaic, $4,183 When cold fusion technology matures the engines should cost roughly as much as automobile engines. I say this because they will be mass-produced, with low efficiency, and they will be of small capacity. They will be mass-market machines, whereas a combined cycle gas turbine is a specialty item manufactured in small numbers. You can buy a Chevrolet 195 HP replacement engine for $1,460, quantity one: http://www.jegs.com/i/GM+Performance/809/10067353/10002/-1 That's 145 kW. In other words, it costs ~$10 per kilowatt, compared to $2,095 for a natural gas generator, or $4,183 for solar PV. That is approximately the extent of the cost advantage cold fusion will eventually have. It will be a factor of 200 to 400 times cheaper than any other energy source. That is not even factoring in the cost of the energy distribution infrastructure (the electric power grid). Granted this is just the cost for the engine, and not the generator portion. Granted also, these engines are not optimized for a 24-hour duty cycle. On the other hand, a cold fusion version can be even simpler and less efficient than today's automobile engine, and thus cheaper. When they are mass-produced in large numbers they are likely to be cheaper than an automobile engine. They should be a piece of cake to install, without significant "site preparation, drainage, buildings" or underground this or that. They should cost about as much to install as today's air conditioner or a gas fired backup generator. These range from $2,000 to $10,000 to install, depending on the size. - Jed
