It takes a huge amount of pressure and temperature to get started and maintain stably. Fusion experiments kept going so far are highly inefficient and take more energy to do than they produce.
The main disadvantage is that, as of 2012, it is not technically feasible.
The major problem with a nuclear fusion reactor is that a 50,000,000 degree temperature is needed. No metal vessel can hold that temperature safely for a long period of time.
The main one is that nobody has made it work yet
There is mainly one disadvantage, namely, that it hasn't been achieved yet - or at least, not in a way that is controlled, and commercially viable.
The idea of nuclear fusion occurring at room temperature is called cold fusion.
Nuclear fusion doesn't produce energy.
nuclear fusion make more energy and they both make energy and have waste products
Nuclear fusion is itself a difficult enough one to crack!
You can find nuclear fusion in a star.
nuclear fusion
Nuclear Fusion
Combining two atomic nuclei is called nuclear fusion.
Fusion is a nuclear reaction.
The idea of nuclear fusion occurring at room temperature is called cold fusion.
Nuclear fusion produces nuclear energy
That would be nuclear fusion, like what happens in stars, when two hydrogen nuclei combine to form a helium nucleus.
Nuclear fusion
Nuclear fusion doesn't produce energy.
nuclear fusion
nuclear fusion make more energy and they both make energy and have waste products
In nuclear fusion mass transforms into energy.