The very idea of a galactic energy mix makes very little sense, in no small part because it is impossible to share energy production between planets or star systems. While it would be technically possible to produce galactic statistics pertaining to energy production on human planets, the sheer variety of planetary settlement types and power needs would make this endeavour absolutely meaningless. What can be done, however, is to identify various types, or profiles, of planetary energy mixes in human space.

The single largest energy mix is to be found on Earth, home to the vast majority of humankind. The terran energy mix (fig.1) is the result of a long and complex history, marked by the collapse and subsequent reconstruction of human power networks in the Low Age. Though nuclear power sources (fusion and fission) represent up to 40% of this mix, the relative political fragmentation of the Earth and the bottom-up communal structure of its superpowers have prevented these complex, centralized power sources from becoming prevalent. Fusion and fission thus play a crucial support role, providing a centralized baseline of power that acts as a safety net for the wide variety of renewable energy sources that power the Earth's communities. The key word, as usual with everything Earthbound, is diversity. No other planet relies on such a complex energy mix profile.

Energy mixes built from the ground up on recently settled worlds are on average much less diverse, and skewed towards specific technological choices made by the first colonists. Elora is a very good example of this phenomenon (fig. 2). Fission is virtually absent on Elora, with the planet's very strong baseline of permanent power relying on fusion plants (often deriving from space-based cores) backed by geothermal and orbital solar stations. The rest of the energy mix is adapted to the planet's oceanic nature, with one fifth of local power generation coming from Elora's strong currents and tides. This is the young prosperous colony type.

Large stations like Irenia's capital of Phi Clio (fig. 3) have very stereotypical energy mixes, with an over-prevalence of fusion power, often built in two waves -- one at the initial station deployment (station cores) and one later down the line (additional cores). The rest of the baseline is covered by Lagrange-stabilized orbital solar stations, especially in the energy-rich Pleiades region. This is the station type.

While fusion/fission baselines are present in most energy mixes, some of them have decided not to include them, the most interesting one being Mundis and its purposefully lower-tech energy mix (fig.4), that almost exclusively relies on intermittent power sources that balance each other all year long. Wind power on Mundis is used both to generate electricity, or to provide mechanical energy to factories and devices directly -- effectively replicating the 18th century windmill economy. The local gas giant of Iteren also provides a small amount of beamed power to top off the planetary energy mix when needed. This could be considered as the full intermittent type.

The snowball type is found on cold planets and often shows a prevalence of fusion/fission and geothermal power sources. Smyrnia (fig.5) is the largest planet with this subtype, though its anarchic nature makes fission deployment impractical, while geothermal power only requires to drill through the ice. If Smyrnia was more stable, the ratio would probably be reversed. 

On the other end of the spectrum, tidally-locked planets follow the renewable baseline type, as the presence of a permanent terminator between the night and day sides effectively mean otherwise intermittent power sources become permanent -- hence the somewhat surprising prevalence of wind power in the energy mix of Ishtar, backed by fusion and a puny quantity of solar power, struggling under the local red dwarf. 

Waterworlds obey to a similar logic, with the ocean world type of energy mixes, relying on thermoelectrical devices leveraging the temperature differences between the surface and the abyssal regions as well as tidal power, both being extremely reliable and almost permanent power sources on waterworlds.

The very idea of a job market would sound utterly alien to the denizens of human space, with the concept of people having to put their skills and time to sell on a market controlled by job givers bordering on madness. Conditional salaries are a tool of capitalistic oppression, but most importantly they are confined to history books. Under the cooperative and communal organisation of human space, one of the most fundamental imperatives of any self-respecting polity is to decouple work from the means of subsistence. This endeavour is not carried through basic income (which is often considered as "the spare wheel of capitalism") but through a much more comprehensive system, which renders the very existence of capitalistic economies impossible: unconditional lifelong salaries.

Under a communal system, everything is socialized, from factories and agriculture to healthcare and transportation. Cooperatives and communes do not own the means of production directly: they are but the structures through which citizens own and control the means of production via democratic processes. Inside a commune, there is no difference between public or private economies, nor between capitalistic and non-capitalistic economies. Everything is shared and socialized.  Within such a shared economy, it stands to reason that profits are to be socialized as well. One half of this socialization process is implemented through communal and cooperative investments in infrastructure, healthcare, transportation or services. The other half is the unconditional lifelong salary.

Every single member of a commune, regardless of ability or availability, is entitled to a lifelong income that is necessarily separated from work and employment. Whether they work directly or not, citizens of a commune are the collective owners, managers and beneficiaries of the wealth produced by their cooperative and as such are entitled to this income due to their very existence. There are no strings attached to lifelong income, which is always paired with extensive welfare and social security measures in order to flatten external inequalities. In effect, unconditional lifelong salary abolishes job markets, capitalism and the very notion of mandatory work altogether. It is the central element of something that is more than just an economic organisation but a true civilisation system, one that considers every kind of activity worthy of a salary, regardless of its value in the capitalistic sense. In effect, the lifelong salary system rewards activities such as raising children, doing free art, maintaining your garden, helping your neighbours...which do contribute to a GDP yet aren't considered as valuable in salary terms under a capitalistic system. Employers still exist in some capacity, but one's subsistence doesn't hinge on employment any longer. 

Lifelong salaries are not completely flat. In most large communes they follow a system of tiers that are tied to diplomas and qualifications, with each additional tier increasing the lifelong salary: in the most archaic communes, the upper tier may be two to three times higher than the lowest tier. Tiers may sometimes be complemented by bonuses attached to high-risk or difficult activities that would not attract workers otherwise. The base amount and tiering of the lifelong salary is one of the most crucial aspects of communal governance, one through which cooperatives and communes live or die. In communes where these incentives aren't enough to cover hard or difficult jobs no one wants to do, mandatory communal work may be implemented for those able to participate, though it is a rare occurrence.

Note that the word "commune" is used in a generic sense in this article. When communes are integrated under the umbrella of a state such as the USRE or the Eloran Ekumen, this state generally handles the financing and management of lifelong salaries on its own. Communes may then have the choice to either merge their budget with the state budget or pay a "salary tithe" to the state while keeping independent investments.  The Eloran Ekumen follows a hybrid model where one half of the lifelong salary is paid for by the state and the other by the qiths.

Shutterstock image. 

The economy of the interstellar age is very different from what it was before the Low Age. The abundance of natural resources in space means that bulk trading of interstellar commodities makes little sense. The prevalence of 3D printing and organic assembly means that the real market is one of open-source manufacturing data. With light lag preventing the fast exchange of economic data, the only real competitive markets exist with rare, unique commodities tied to a specific planet or culture.

1 - Resource trading, or the age of availability

The Low Age was a time of resource scarcity and local economies after the wanton consumption and destruction of the industrial era. Spreading to the stars changed this paradigm in many ways, the first one being the availability of basic resources. Advances in manufacturing, space propulsion, 3D printing and organic synthesis mean that a settlement only really needs four things to thrive: nutrients, metals, water and energy.

Water is incredibly easy to come by - while liquid water is rare, water ice is one of the most common resources in the galaxy, to the point some spaceships, like the famous spacecoach, are practically made of the thing. Water ice can be very easily collected and traded inside a system, with no need for interstellar trade.

Energy isn't exactly hard to find either, though its availability is more variable. There is no real unique source of energy in human space, though most systems operate on a mix of nuclear fusion, organic production and solar panels/wind turbines. Fusion only requires hydrogen from water or gas giant atmospheres, and renewable sources rely on positioning (gas giants are particularly prized as energy generation sites) rather than tradeable commodities.

Metals are a bit trickier to harvest but not much more than water ice. The vast majority of hard metals and rare earth minerals required by modern engineering can be found in rocky asteroids or spent comets, with little need for planetary mining sites. Now, metal abundance isn't the norm for all systems: for instance, systems with low metallicity stars like red dwarfs tend to have issues with metal availability, however, these systems are also very rarely settled, being cold, low-energy, hostile places. There are a few exceptions to this rule, however, such as the Trappist worlds, which are unusually rich in metals for red dwarf planets. Aside from isolated stations, there is little real need for interstellar metal and rare earths trade.

Soil nutrients are probably the most complex part of resource harvesting. Compounds such as nitrogen, ammonium or potassium can be found on asteroids, planetoids or in planetary atmospheres. Though they are not rare compared to human needs, they require more expertise and techniques than metal harvesting. Again, outside of isolated stations, the interstellar trade of nutrients makes little sense.

In the end, as far as basic resources are concerned, interstellar trade is nonexistent, with mostly inter-system trade between communes and cooperatives. Economies are local in scope.

2 - Manufactured commodities: the open-source age

The vast majority of complex manufacturing - except on Earth - occurs in space in order to cut the costs of surface to orbit transport and facilitate access to asteroid mined resources, which means it occurs under the umbrella of space-based communes, and they are entirely based around open-source data.

As far as interstellar trade is concerned the rules that apply to resource harvesting also apply to manufacturing: there is little sense in bulk trading at the interstellar scale when almost any commune can set up a 3D printing factory fed with locally exploited resources. The heart of this economy is data - blueprints, more specifically.

And within human space, blueprints mean open-source data. This is the most fundamental economic notion in the space age: what truly matters is data and there is no such thing as privately owned data. While there are secret or hidden blueprints, the immense majority of manufacturing blueprints, from spaceship parts to GMOs or spoons, are open-source data that can be freely shared, reused and built upon. This is an economy based on user collaboration, where designs and concepts evolve with time as new case uses and improvements are designed and there is no financial barrier to data access, an economy made possible by the post-capitalistic system of the communes. With light lag and interstellar communications delay, this open-source system exists in bubbles, so to speak, with each system having its collaborative forums and where innovations expand in "waves" between stars as courier ships travel through the void.