I'm designing an alien race that hasn't developed electricity yet. Now, one thing about their species is that they haven't discovered fossil fuels on their planet to use, like coal, oil, etc. (The reason for this isn't clear at this moment but I think I can figure something out later.)

So I was thinking, if a civilization couldn't use fossil fuels as a starting point for generating energy, what alternate sources of energy would they begin with? Are renewables an option, or does that require more advanced technology in order to make? Another option, is the fact that plants on their planet have nervous systems, and maybe they could extract energy from them, however I think that still requires technology that is far ahead for their civilization and I'm not certain if such an "energy source" would last long or give enough energy.

So my question is, if a civilization can't use fossil fuels to develop, then what other energy sources exist as a starting point?

Note: I don't know if this is useful information or not, but they use bioluminescent plants to light up their cities at nights instead of making fire or gas lights.

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    $\begingroup$ Burning wood and plant and animal oils seems obvious. Any reason why they can't use those? $\endgroup$
    – nzaman
    Commented Dec 30, 2018 at 18:33
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    $\begingroup$ Human civilization did not use fossil fuels until the second industrial revolution, in the 18th century. The ancient civilizations, the medieval civilizations, the early modern civilizations did not use fossil fuels. (All right, they used a very little coal, in some places and for limited purposes.) Hint: wood, wind, rivers, oxen, horses. $\endgroup$
    – AlexP
    Commented Dec 30, 2018 at 18:34
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    $\begingroup$ An obvious reason for them not having fossil fuels is that a precursor race used them all. And then went extinct due to the effects of global warming, leaving the new race to evolve intelligence in less time than it takes to form fossil fuel deposits. Think current humans, and the new intelligence evolving from rats :-) $\endgroup$
    – jamesqf
    Commented Dec 30, 2018 at 19:06
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    $\begingroup$ Whale oil is a good candidate. $\endgroup$ Commented Dec 30, 2018 at 20:52
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    $\begingroup$ aka: WWII and why England has no trees. $\endgroup$
    – Mazura
    Commented Dec 30, 2018 at 21:50

10 Answers 10



You said they don't have access to fossil fuels, but not to a forest. Using wood as fuel can be a good way to start gathering energy, in form of steam engine if you are looking for mechanical energy instead of heat. For the link:

A common hardwood, red oak, has an energy content (heat value) of 14.9 megajoules per kilogram [...]

Wood as fuel can be used in firewood, chips, wood pellets or sawdust, as residue from other process.

After your species advances more technologically, and want, for example, melt iron, they will develop charcoal using charcoal burner. From there, and there:

Charcoal burns at temperatures exceeding 1,100 degrees Celsius (2,010 degrees Fahrenheit). By comparison the melting point of iron is approximately 1,200 to 1,550 °C (2,190 to 2,820 °F). Due to its porosity, it is sensitive to the flow of air and the heat generated can be moderated by controlling the air flow to the fire. For this reason charcoal is still widely used by blacksmiths. Charcoal has been used for the production of iron since Roman times and steel in modern times where it also provided the necessary carbon. Charcoal briquettes can burn up to approximately 1,260 °C (2,300 °F) with a forced air blower forge. [...] Historically, charcoal was used in great quantities for smelting iron in bloomeries and later blast furnaces and finery forges.

Even more, you can make syngas with wood:

Like many other sources of carbon, charcoal can be used for the production of various syngas compositions; i.e., various CO + H2 + CO2 + N2 mixtures. The syngas is typically used as fuel, including automotive propulsion, or as a chemical feedstock.

In times of scarce petroleum, automobiles and even buses have been converted to burn wood gas (a gas mixture consisting primarily of diluting atmospheric nitrogen, but also containing combustible gasses, mostly carbon monoxide) released by burning charcoal or wood in a wood gas generator. In 1931 Tang Zhongming developed an automobile powered by charcoal, and these cars were popular in China until the 1950s and in occupied France during World War II (called gazogènes).


From ancients times there is a certain machine called water mill. From the link.

A watermill or water mill is a mill that uses hydropower. It is a structure that uses a water wheel or water turbine to drive a mechanical process such as milling (grinding), rolling, or hammering. Such processes are needed in the production of many material goods, including flour, lumber, paper, textiles, and many metal products. These watermills may comprise gristmills, sawmills, paper mills, textile mills, hammermills, trip hammering mills, rolling mills, wire drawing mills.

The water wheel is medieval technology, while the water turbine is current technology.

Watermill works gathering mechanical energy from a flow of water, like a river.


In addition to watermills, there exist Windmills which channels mechanical power from the wind itself. From the link:

A windmill is a mill that converts the energy of wind into rotational energy by means of vanes called sails or blades. Centuries ago, windmills usually were used to mill grain (gristmills), pump water (windpumps), or both. The majority of modern windmills take the form of wind turbines used to generate electricity, or windpumps used to pump water, either for land drainage or to extract groundwater.

The today technology is called wind turbine.


Additionally, you can use animals, primary horses, in a horsemill. From the link:

A horse mill is a mill, sometimes used in conjunction with a watermill or windmill, that uses a horse engine as the power source. Any milling process can be powered in this way, but the most frequent use of animal power in horse mills was for grinding grain and pumping water. Other animal engines for powering mills are powered by dogs, donkeys, oxen or camels. Treadwheels are engines powered by humans.

  • $\begingroup$ You can also turn biomass into ethanol and almost directly replace gasoline. Your car is likely running on some percent today, and they have 100% ethanol (E100) vehicles in Brazil. Biodiesel is another option too, which can also be used in gas-turbine aircraft engines and power plants. $\endgroup$
    – user71659
    Commented Dec 31, 2018 at 22:12

Poop! Poop! And more Poop!

But seriously, dried animal dung is a very common fuel, even today in some places.

You can burn it like wood.

Dry dung fuel (or dry manure fuel) is animal feces that has been dried in order to be used as a fuel source. It is used as a fuel in many countries around the world. Using dry manure as a fuel source is an example of reuse of excreta. A disadvantage of using this kind of fuel is increased air pollution. In India, this kind of fuel source is known as "dung cakes". (ref)

You can power machines with it.

enter image description here
Stirling-Motor powered with cow dung in the Technical Collection Hochhut in Frankfurt on Main (ref)

You can power transportation.

The UK debuted its first poop-powered buses, which will transport about 10,000 monthly comm​uters between Bath and Bristol Airport. These "Bio-Buses" are the fruit of a partnership between the Bath Bus Company and Bristol's sewage treatment system, which is run by a company called GENeco. They can travel about 186 miles on the yearly waste of five people, offering a more sustainable alternative to natural gas-powered vehicles. (ref)

You can turn sewage into fuel in a variety of ways.

True to its rich history, poop-based energy has now evolved into a multifaceted and diverse set of industries. In 2004, a waste management facility in Renton, Washington received a $22,000,000 gr​ant to build a power plant that could turn sewage into electricity. The same year, a rancher figured out how to power his dairy far​m with cow patties and an engineering professor turned pig crap into​ crude oil. (ref)

You can turn manure into natural gas.

Natural gas, though a significant contributor to climate change, is the cleanest-burning fossil fuel. Turning cow manure into natural gas would have three big advantages. First, it would turn animal waste, a major source of carbon pollution, into a useful fuel. Second, it would provide a new source of natural gas, which could be used to replace dirtier fuels like coal and oil. Third, it would reduce the need for fracking, the environmentally-destructive practice that extracts natural gas from the earth. (ref)

Livestock waste yields biogas which is refined into natural gas
Livestock waste yields biogas which is refined into natural gas (ref)

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    $\begingroup$ You can't use pipelines with natural gas at ambient pressure; really, there's no practical way to use natural gas at ambient pressure we know of - it's one of the reasons why plans to use biogas never got anywhere, you need a lot of energy to compress (or liquify) the gas to be practical. In contrast, natural gas comes conveniently pre-compressed (flare stacks are usually used where the gas doesn't have enough pressure to be useful - it's less of a waste to burn it off than to compress it). That said, if you have nothing cheaper and lots of energy, it could still be a convenient fuel. $\endgroup$
    – Luaan
    Commented Dec 31, 2018 at 14:03
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    $\begingroup$ @Luaan thanks for the details. My intention was to show how this source could be used as fuel immediately (any culture with the technology of firemaking can collect, dry, and burn dung) and then how it could progress as technology progressed. Just like human society went from burning lumps of coal they found to all sorts of different fuel tech, plus high level mining techniques (since the surface coal got used up fast). $\endgroup$
    – Cyn
    Commented Dec 31, 2018 at 15:20
  • $\begingroup$ @Luaan your comments are all exactly on point and show your expertise in this field. Why not combine them into an answer? It would be easier for everyone to see what you have to say (and you deserve the rep). $\endgroup$
    – Cyn
    Commented Dec 31, 2018 at 15:26
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    $\begingroup$ Well, Ender's and your own answers are already very good, with just a few small things that need to be considered. The main addition to your answer is why we're not using biogas quite as much as you might expect - if you don't have a better alternative, it would definitely be worthwhile. Just don't expect them to have such massive growth as our own industrial revolution - that was largely powered by our exploitation of fossil fuels (first using coal to pump water from mines, then using coal for making steel). Still, better than wood alone - wood is very limited in quantity. $\endgroup$
    – Luaan
    Commented Dec 31, 2018 at 15:42

Wind and water

To answer your question, look no further than the old industrial regions of the US and Europe right before coal became commercially viable. Every town had a mill pond, and below it, industry. Mills, presses, machine works, you name it. Plants had central shaft drive, with belts driving individual machines. That came off a water wheel.

Wind was used to pump. The famous Aermotor windmill, for instance. They are still in business, and are fairly crabby about people asking them how to make electricity with their windmill. Theirs is made to pump.

Transportation? Canals. That is how coal first made it to market in large enough quantities to become commercially useful.

Electricity transmits

For development of electricity, lack of fossil fuels wouldn't even be a speed bump. The first electric plants of any scale were hydro - starting for instance with facilities at Niagara Falls. It is still a large piece of the energy pie, especially in places rich with it, like eastern Canada and the American South. It even shows up in dry, dry California - flow is very poor but exploitable height makes up for it, like Oroville with a paltry 2000 CFM flow but 700' of head.

Coal already had it feet planted, but if it hadn't, windmill manufacturers would have had no trouble figuring out how to design windmill blades to run the right speed and autofeather so windmills can sync onto the power grid and do useful work.

There's a real problem with wind "cutting out on you" arbitrarily. In a hydro-heavy world, you solve that by using wind-generated electricity for backpumping (pumped storage). You have a significant pound (lake, reservoir, impoundment) at the bottom and the top of a hill. When there is a wind surplus, that energy is used to pump the water from the lower pound to the upper. (Aermotors would work on a primitive windmill-at-the-hill setup). When the wind slakes, water falls down through turbines. Examples: the pumped-storage projects at Muskegon and Niagara. (At Niagara the top pound is much higher than the top of the falls).

This function adds extremely well onto existing hydro dams - just build or adapt the system to include a pound at the bottom of the dam. The pound doesn't even have to be anywhere near the dam, just at the same altitude, e.g. The Thermalito Forebay, which is the lower pound at Oroville but miles away from it. Oroville backpumps from the far-too-small Thermalito Diversion Pool at its base, but as water level drops, water flows backwards from the Forebay to refill it.

Total grid capacity is then limited by the hydro capacity + average wind. The commercial market sorts out the rest.

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    $\begingroup$ Yeah, coal power won mainly because it allowed you to build your factory pretty much anywhere. Before coal, almost all industry needed access to a good river, and that limited expansion quite a bit. Would windmills work? I doubt it. Windmills only work if you don't need sustained power - e.g. a grain mill doesn't care the wind stopped for an hour or two, an iron smeltery/forgery does. Even for electricity, it's tricky to provide reliable supply - even with our tech level, it's not easy (and some say it's still too much of a hurdle to provide more than a fraction of our total power supply). $\endgroup$
    – Luaan
    Commented Dec 31, 2018 at 14:12
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    $\begingroup$ @Luaan I added pumped storage, which licks the windmill problem. In fact, a primitive hilltop pumped-storage setup, with the windmills placed on the hilltop and surrounding valleys, could use the traditional Aermotor pump windmill. Obviously the limited number of hilltop sites limits the scheme, this world won't have anywhere near the power supply ours does, with prices reflecting that. But paucity of power does not wreck standard of living... Look at how off grid solar homes are built, that would be standard here. $\endgroup$ Commented Dec 31, 2018 at 17:25
  • $\begingroup$ +1 for water power. Steam-powered factories could have easily used multiple smaller engines, but they already had established power transfer systems from the original water powered designs. Steam engines were simply bolted into existing systems, which made adoption much easier. $\endgroup$
    – Graham
    Commented Jan 1, 2019 at 15:28

In addition to @Ender Look's answer, I propose to you,


The first patent for a solar collector was obtained by the Italian Alessandro Battaglia in Genoa, Italy, in 1886. Over the following years, invеntors such as John Ericsson and Frank Shuman developed concentrating solar-powered dеvices for irrigation, refrigеration, and locomоtion. In 1913 Shuman finished a 55 HP parabolic solar thermal energy station in Maadi, Egypt for irrigation.

I am talking about concentrated solar power to be more specific, where solar rays are concentrated to heat water which turns a turbine.

EDIT: I've seen people point out the fact that access to metals needed for large-scale solar generation wouldn't be easy. But perhaps solar would come later as industrialization opens up more options.

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    $\begingroup$ I don't think it would be practical to make a solar collector in a pre-industrial society. $\endgroup$
    – Daniel B
    Commented Dec 31, 2018 at 0:02
  • $\begingroup$ I don't think people realize how straightforward it is to use solar power... (e.g. en.wikipedia.org/wiki/Solar_cooker ) $\endgroup$
    – NofP
    Commented Dec 31, 2018 at 9:46
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    $\begingroup$ @NofP Yeah, that's primitive and cheap... in an industrial society. Don't underestimate how much cheaper things like clear glass or refined metal got as a result of the industrial revolution. We're only within reach of efficient use of solar power now thanks to all the investment that was afforded by using tons of fossil fuels :D $\endgroup$
    – Luaan
    Commented Dec 31, 2018 at 14:04

Geothermal Vents. You could use heated water, steam, and just the hot ground for heating. You could use hot gaseous material expelled from the ground (through a vertical vent) to generate rotational power or even use the hot gas to propel something like a hot air balloon into the atmosphere for short periods of time, or have the balloon anchored or tethered to the earth (rope) with a tubular connection to the 'air' balloon from the vent to maintain its aerial advantage over other 'tribes' or for some other mechanical advantage. Gaseous/liquid material can also be used for other things. Sulfuric in natural (or perhaps not on your world) it could be used to produce an acid based material, and then with mined metals, you could chance upon electricity via the 'electric' or lead acid battery. The acid/battery system could be contained (pottery) and available for excursions from your home. Defense - you could use gaseous/liquid system for defense against other tribes, animals, etc. Manufacturing - the gaseous/liquid materials could be used in materials production. Perhaps your system also produces Nitric acid, allowing/resulting for fertilizer production and greater food growing opportunities near the vents. You would find many useful materials 'crystallizing' out of these vents as they vent into the air, water, caverns. Your civilization(s) near the vent may be more productive/successful than those trying to survive far away from them.

I could go on and on. Lots more to add - let your imagination inspire you.

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    $\begingroup$ Geothermal vents don't really work all that well on their own; it's one of those things that only became practical due to lots of high technology, and they actually decay over time (a typical lifetime for a geothermal plant is around 30-50 years, then it needs a century or two to replenish the heat to be practical power sources again). Even people in reach of really good geothermal vents (and who made use of them for e.g. bathing) didn't use them even for heating their homes - they used wood like everyone else (who could afford it). For a low-tech society, water power is far more practical. $\endgroup$
    – Luaan
    Commented Dec 31, 2018 at 14:08

They will start with wood, and from that, charcoal. With access to charcoal comes metallurgy, better charcoal, and more metallurgy. Mechanical work can be done with aero- and hydro- mechanical power (i.e., water mills, windmills, etc.).

If they require large scale industrialization, they'll probably need to ramp up their production of high-energy-density fuels. Oil and coal are some of the most energy dense chemical fuels known among the low-tech ones (gasoline stands at 46 MJ/kg, diesel fuel is around 48; by comparison, methanol is around 20, and wood gas ranges around 30 depending on actual composition.

So I think we need to include a phase where they "distill" vegetable oils, say, to diesel fuel, or start mass-producing artificial coke from wood char. This might require large cultivations.

Then, from metallurgy and electromagnetism, comes hydroelectric power, and wind electric power. Also, thermosolar power (use of concentrator mirrors to drive a steam engine, or produce high-density fuels through pyrolization).

If at some point they discover the photoelectric effect, after some time, they'll also have photovoltaic solar power. This might be a marginal source in our technology and culture, but a renewable-power-bound civilization would soon realize that their actual energy source is their Sun. So it stands to reason that they would strive to maximize their Sun-capturing efficiency.

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    $\begingroup$ They will not use coal (or petroleum) if they don't have coal. $\endgroup$
    – jamesqf
    Commented Dec 30, 2018 at 19:03
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    $\begingroup$ Yes, fixed answer. I meant 'charcoal' -- English is not my native language, and it shows :-) $\endgroup$
    – LSerni
    Commented Dec 30, 2018 at 20:26
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    $\begingroup$ You don't really need photovoltaics; they're not all that practical unless you need very low mass (like for spacecraft) or small supply for remote locations. I'd guess if they had access to concentrated solar plants, they wouldn't bother investing in photovoltaics. $\endgroup$
    – Luaan
    Commented Dec 31, 2018 at 14:14
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    $\begingroup$ +1. Energy is easy, from many different sources. Finding enough fuel that will burn hot enough to mass produce steel is difficult. $\endgroup$
    – Mazura
    Commented Dec 31, 2018 at 23:34

Direct answer: Water (if the planet has elevated lakes or rivers) and/or the plants you mentioned (if the plants can burn)

Basically when the planet has rivers or elevated lakes the aliens could build hydroelectric power plants and generate the energy though them

Or burn plants to heat air or any other gases/fluids to turn turbines and generate electricity this way.


Peat is also used extensively in certain areas. Don't know if you want to count that as a fossil fuel or not.

  • $\begingroup$ Welcome to Worldbuilding.SE! We're glad you could join us! When you have a moment, please click here to learn more about our culture and take our tour. You've brought up a good question, since peat is, well... technically a fossil fuel. Clever idea, though. Thanks! $\endgroup$
    – JBH
    Commented Jan 1, 2019 at 3:57

No electricity & no fossil fuels

Wood (including charcoal), vegetable oil (aka bio diesel), alcohol & methane are all non fossil fuels that have been (& would be) used : non fossil analogues of all our extant fossil fuels exist & are all usable in ordinary technology & infrastructure as it exists today.

So your world really doesn't have to look much different from our own.

More land would be given over to fuel crops (fast growing trees, oil rich plant seeds, potatoes etc to ferment into alcohol) so you might presume maximum sustainable populations are reached sooner as less land is available for growing food if you're growing fuel crops.

But other than that I don't see any plausible reasons for any major differences.

Right up until well into the industrial revolution in our world there was no electricity & everything we used coal & other fossil fuels for had commonly available non-fossil fuel analogues that could have been used instead.

Windmills & watermills probably never went out of fashion to quite the extent that they did in our reality & might experience a resurgence for electrical power generation (when/if they do discover it) while solar power would likely be more widely adopted earlier than in our world (when/if discovered).

But overall none of that's going to make a major change to the way things are or look.

Moving on into the later part of the 19th century when electricity & petroleum really took off is where you'll start seeing differences.

There'll be no plastic bags or any of the common types of artificial fibers for clothing we use now.

Global warming might not be the issue it is for us today as carbon dioxide will get taken out of the atmosphere by the growing fuel crops as fast as the fuels that are burnt put it into the atmosphere but the hole in the ozone layer might have still happened as that was largely down to aerosol CFCs.

Household appliances will be limited to mechanical ones like push lawnmowers or hoovers with hand operated bellows along with perhaps some steam powered ones (like washing machines perhaps).

If they discover electricity later but still have no fossil fuels they can just use wood burning steam turbines to generate electricity, large sections of woodland would be planted with fast growing trees & harvested in rotation, while wind, hydro & solar power would be much bigger than it is with us now.

But really it would still look very much like us now just with more land given over to things like energy crops & wind-farms.

In summary: you'll have larger stretches of arable land between cities & need more acreage per person to support similar levels of power use to us now but in the cities & towns themselves you wouldn't see any difference other than it takes longer to travel between them.


Assuming your aliens are aquatic or amphibious, it's possible they might use hydrothermal vents, vents at the bottom of the ocean where water is heated by geothermic processes: https://en.wikipedia.org/wiki/Hydrothermal_vent
On Earth, these vents are surrounded by chemoautotrophic bacteria that use the dissolved minerals in the heated water as the basis for a food web centered around chemicals, not sunlight. Your aliens might use the hot water from these vents to drive steampunk engines and smelt metals.
Moreover, this could have interesting societal effects, with cities being built around these vents, powered by hot water and fed by sheets of bacteria, while surrounded by wastelands home to low-tech barbarians and wanderers.


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