In order to successfully colonise Mars we’ll need access to plenty of energy. On Earth, access to abundant fossil fuels (coal, oil and natural gas) enabled the industrial revolution and continues to power human civilisation into the 21st century. Energy is necessary for heating, lighting, refrigeration, cooking and other essential basic functions of society, but perhaps most importantly it’s required by both machinery and electronics, enabling mass production, transportation, communications, computing, and all manner of automation. Modern technological society is largely dependent on machinery and electronics, and we can safely assume this will also be the case on Mars. In fact, energy requirements per person will be greater on Mars than on Earth due to the need for ECLSS (Environment Control and Life Support Systems) in habitats, pressurised vehicles and marssuits.
On Earth, the bulk of our energy comes from fossil fuels and biomass. However, as far as we know, Mars has neither of these. Mars also has no active hydrosphere, which also rules out hydroelectric, wave, tidal, and ocean thermal energy.
Here’s a breakdown of energy supply on Earth in 2010:
Thus, we’re currently obtaining over 80% of our energy from fossil fuels, but less than 1% from “Other renewables”, which includes solar, wind, wave, tidal, geothermal and ocean thermal energy sources.
On Mars, all of these are ruled out except for:
- nuclear fission
- areothermal (this is the equivalent term for “geothermal” on Mars)
Other options that are yet to be developed but may prove practical for Mars include:
- nuclear fusion
- space solar power
Because most energy on Earth is currently obtained from fossil fuels, most of our experience and technology related to energy production is based on harnessing these fuels. Therefore, it may at first seem like a serious challenge for settlers that Mars doesn’t provide these.
Many people say climate change is bad, but aside from all the likely death, destruction and general pandemonium, it’s also driving many positive changes on our planet. One of these, which we’re currently observing, is massive investment in new, cleaner forms of energy production.
This increase in investment and innovation is also being driven by the stark and somewhat worrying reality that fossil fuels are being consumed more rapidly than they’re being discovered or extracted, and certainly far more rapidly than they’re being made, which takes millions of years. If current demand for oil remains static, we have an estimated 120 years worth remaining on Earth. However, demand for oil is, of course, escalating exponentially as a function of both population increase and economic and technological development across the globe, and, without an effective replacement, world oil reserves could potentially be fully depleted before the end of the 21st century.
Therefore, the business case for investment in solar, wind and other renewable energy sources is solid, with about $257 billion being invested in 2011, increasing by around 20% or more per year. This is very fortunate for those of with our sights on Mars, because much of this newly developing technology can be used on the red planet.
Investment in nuclear fission has been low since the Chernobyl accident in 1986; however, there has been a renewed interest in nuclear fission lately as several environmentalists have spoken out in support of it. This may seem counter-intuitive; however, nuclear is currently viewed as less of an environmental hazard than fossil fuels, mainly because our most pressing environmental concern is currently the high concentration of atmospheric carbon dioxide caused by fossil fuel combustion. Although most environmentalists would much prefer global civilisation to be 100% powered by renewable energy sources, many experts consider it unlikely that renewables can be scaled up from their current low level quickly enough to prevent catastrophic global warming, especially considering the lack of cost-effective and environmentally-friendly energy storage solutions.
Nuclear fission is a more mature technology than most renewables, and proven as a source of cheap, abundant, continuous energy. There is still a broad public perception that nuclear fission is unreasonably dangerous, however, and that nuclear waste is also a serious environmental concern. However, several new “Generation IV” reactor designs currently in development do not have the issues that can cause Chernobyl-style disasters. One particularly promising type is the LFTR (Liquid Fluoride Thorium Reactor), which uses thorium as fuel. Thorium is much more abundant than uranium (also on the Moon and Mars), and therefore cheaper, and LFTR’s cannot melt down and can actually consume existing nuclear waste as fuel. Nonetheless, regardless of safety protocols or design, any type of fission reactor can potentially break and radioactively contaminate the environment, whether due to design or manufacturing error, operational mismanagement, natural disaster or warfare.
The most likely outcome will be that the 21st century will see massive investment in both nuclear fission as well as all major forms of renewables, and these will both gradually replace fossil fuels. If these energy sources are scaled up and deployed rapidly enough, it may even be possible that fossil fuels do not become fully depleted, at least not in the near future. The insane practice of fracking can stop, and oil can be reserved for making plastics, synthetic rubber, lubricants and other materials.
Fission may get us out of trouble in the near term, but will probably be phased out during the second half of the 21st century, as renewables such as solar, wind, wave, tidal, geothermal, ocean thermal and space solar power become increasingly advanced, widely deployed and cheap, and present a safer and cleaner option.
With regard to nuclear fusion, if developed, it’s my opinion that it will never be needed on Earth once renewable energy is abundant and cheap, which seems likely to happen sooner. However, fusion energy could prove ideal for spaceships, space stations, and lunar, asteroidal or other extraterrestrial settlements with few renewable energy options.
The current shift away from the use of fossil fuels towards nuclear fission and renewables on Earth is a boon for Mars settlers, as we can take advantage of the innovation and technological developments in this area. The development of energy production systems on Mars may even closely mirror that of Earth, with fission playing an important role in the early stages of Mars exploration and settlement, providing, as it does, an abundant supply of continuous energy, but ultimately being phased out in favour of renewable sources. As infrastructure and manufacturing capabilities are developed on Mars, including the ability to 3D print photovoltaic cells and wind turbines; as possible areothermal energy sources are discovered and exploited; and as the technology required to tap renewable energy sources and to store energy are improved and optimised for Mars, it’s reasonable to expect an eventual abandonment of nuclear fission in favour of clean, simple and safe renewables.