It depends on the type of fuel used. The holy grail is a boron + hydrogen reaction, which produces three helium nuclei. Since the nuclei are positively charge

It depends on the type of fuel used. The holy grail is a boron + hydrogen reaction, which produces three helium nuclei. Since the nuclei are positively charged and moving quickly, the net voltage is around 2 million volts. When done correctly, fusion will create electricity directly. At that point it's just a matter of stepping it down to a usable voltage, but we have lots of ways to do that.