Without the ability to generate large amounts of electricity to power the latest technology, there would be no spacefaring cultures. Powerplants come in many shapes and sizes, a dizzying array of efficiencies, and each species demands varying requirements of their designs and technicians.
Powerplants are not strictly limited to generating electricity, however. Some are multi-purpose.
Types of electrical powerplants
Nuclear
Nuclear power is still widely used throughout the galaxy; nuclear fusion is the most common method of generating electricity. Pre-Enlightenment, cold fusion was impossible. Today, many modern devices are powered by it or, alternatively, bubble fusion. Hot fusion is utilized for greater loads.
Examples of hot fusion powerplants are polywells, stellerators, superfusors, and tokamaks.
Above: a simplified depiction of sonofusion (bubble fusion).
However, nuclear fission still has it's place in the galaxy among most cultures. It is used when and where large amounts of power are required and excess heat and radiation are non-issues. Seen as relics by post-Enlightenment populaces, gas-cooled and very high temperature reactors are common.
For nuclear propulsion, see drives.
Solar
Photovoltaic cells converts the energy in star- or sunlight to electrical energy. As solid state devices they have the advantage of being compact and simplistic. Solar energy has numerous advantages: it produces no energy byproducts and modern examples are highly efficient. Most cells consist of silicon or other suitable metamaterials.
Power plants using the solar wind, the star's magnetic field or its radiation output also exist, and some clarketech spacecraft are reported to harness thermal energy from stars directly by flying through the corona, but no known contemporary civilisation has yet achieved this feat.
Solar powerplants are not limited to photovoltaic cells and may use mirrors to direct the thermal energy of light to heat a medium. The solar trough, which boils a liquid medium, and a suncatcher, which drives a heat engine, are both examples.
Above: a suncatcher-style solar power unit.
Types of multipurpose powerplants
Combustion
Combustion engines serve two purposes: to generate electricity and to enable locomotion. Both purposes require an engine that uses the compression, ignition, and expansion of air or a similar gas in order to convert kinetic and thermal energy to mechanical energy. This ancient method is reliable.
Internal combustion engines (those which drive gears or pistons) and jet turbines are ideal examples.
Displacers
A displacer powerplant utilizes thermal energy gradients or pressure differentials to generate electricity. These are very simple and reliable forms of energy propagation. A heat engine, for example, takes advantage of outside forces to heat a gas which expands and moves a piston. The image to the right depicts a heat engine.
