How to Colonize an Asteroid
The primary power source for the international space station consists of several banks of solar photovoltaic cells and batteries. The primary power system is supplied with 143 to 160 volts dc, which is then regulated to 124 volts dc for distribution within the station. The difference in these voltages is to allow for reduced output of the solar cells with age, and to compensate for transmission losses within the station.
Power is stored in Nickle Hydrogen Batteries (NiH2) and, in the event of a complete power generation failure, the batteries contain enough charge for the ISS to make one full orbit