It would take some kind of complete revolution. It’s not happening.
These batteries have very poor power density and are very inefficient. The advantages of nuclear-powered batteries are:
- They generate power over a long time, decades,
- They generate some heat.
They don’t generate much power. If you have a building, you would definitely think of a nuclear RTG as a “very shitty battery”, and that’s even if you don’t care at all about radioactivity.
Thinking of these as a “battery” is also a bit misleading, IMO. These are really just small power plants, which generate heat and turn the heat into electricity. The heat is powered by radioactive decay of Pu-238, and then turned into electricity with the extremely inefficient Seebeck effect. If you had a source of heat you wanted to turn into electricity, it’s much more efficient to use that heat to turn a turbine which is connected to a generator. And if you want an efficient, cost-effictive turbine, you make it big. At that point, you have a power plant.
While Pu-238 is an alpha emitter, so it is difficult to capture the decay energy in any other way than by converting heat into electrical energy, for the radioactive isotopes that are beta emitters there is an alternative where the nuclear batteries function in a way very similar to a chemical battery.
The beta decaying substance is connected electrically to one electrode of a capacitor, while the electrons emitted due to the beta decay are able to pass through the insulating layer of the capacitor, reaching the other electrode.
Thus the capacitor is charged directly by the beta-decay and it can provide electrical energy to the external circuit.
Thanks for the insights. I was thinking if we can make nuclear power generation small, it can avoid the stigma associated with big nuclear power plants. At that point it might become a viable source of energy to replace fossil fuels.
These batteries have very poor power density and are very inefficient. The advantages of nuclear-powered batteries are:
- They generate power over a long time, decades,
- They generate some heat.
They don’t generate much power. If you have a building, you would definitely think of a nuclear RTG as a “very shitty battery”, and that’s even if you don’t care at all about radioactivity.
Thinking of these as a “battery” is also a bit misleading, IMO. These are really just small power plants, which generate heat and turn the heat into electricity. The heat is powered by radioactive decay of Pu-238, and then turned into electricity with the extremely inefficient Seebeck effect. If you had a source of heat you wanted to turn into electricity, it’s much more efficient to use that heat to turn a turbine which is connected to a generator. And if you want an efficient, cost-effictive turbine, you make it big. At that point, you have a power plant.