Power Generation Options

There are many different power generation options, available and useful at varying power tiers. So many options are available that it may be confusing to new players. This page lists many of the most viable power generation options, what tiers they are available and useful at, and how to use them.

Steam
Steam is the first power source you have access to and, as such, is simple to use but not really the best option, especially later on. It is available as soon as you enter LV, being the only source of power available at the very start. It can be used through EV, through various sets of gradually better boilers and turbines, however is generally not recommended to be used past MV. Production: Steam is produced in many boilers, of various types. All boilers require 1L of water per 150L of steam produced. If a boiler runs out of water, and is then fed more water while it is still hot, it will explode, so make sure you've got enough water production for your boilers! 2L of steam makes 1 EU, multiplied by the efficiency loss of the steam turbine.

The first set of boilers available are the small Gregtech boilers. All of these are available at the start of LV. Included in this lineup are the Small Coal Boiler. This is the first boiler available, consuming coal or charcoal, and is not really viable for power production, giving a measly 120 L/s of steam, or 3 EU/t of power, or even less with efficiency losses from turbines. The Simple Solar Boiler produces the same amount of steam, but runs off sunlight, and slowly calcifies, requiring it to be broken and replaced to be restored to its full 120 L/s production. High Pressure Coal Boilers produce 300 L/s of steam, a much better number, but still only equivalent to 7.5 EU/t. Like the Small Coal Boilers, these run off coal or charcoal. High Pressure Lava Boilers produce 600 L/s of steam, or 15 EU/t, and run off lava. These require a constant source of lava, which is generally not something available at LV, so these are not recommended for use in constant power generation.

Next are the Railcraft boilers, available at the start of LV. These are multiblock boilers, and can be 1x1, 2x2, or 3x3, and up to 5 blocks tall. These consist of a single base layer of boiler fireboxes, over which between 1 and 4 layers of boiler tanks are placed, depending on the size (look on the tooltip for a list of viable sizes). The boiler fireboxes determine what fuel is used- solid fueled fireboxes can run on anything that is capable of burning in a furnace(mostly coal or charcoal are the viable options, BoP ash from the nether could also be used if you don't mind digging) while liquid fueled fireboxes run off certain flammable liquids (creosote oil, lava, diesel, and oil, though of these the only one you'll want to use is probably creosote). The boiler tanks determine steam production, warm up time, and fuel consumption- low pressure boilers warm up faster (although still very slow relative to other boilers) and make 10 L/t of steam per boiler tank present(Note that this is per tick, not per second unlike the GT boilers- multiply this by 20 to get per second), while high pressure boilers are more expensive, use twice the fuel, warm up much slower, but make 20L/t of steam per boiler tank. Since high pressure tanks aren't any more fuel efficient, warm up much slower, and need steel instead of iron, it's better to use low pressure tanks in nearly all circumstances. Both types of fireboxes are viable, and it's generally best to run a combination of both to fully utilize a coke oven. These can produce anywhere from a tiny 10L/t of steam, or 5 EU/t, up to 360L/t for a max size low pressure or 720L/t for a max size high pressure (180 or 360 EU/t, respectively).

GT++ adds advanced boilers, which are available in 3 tiers from LV to HV. These produce 250L/s, 500 L/s, and 750L/s for each tier. They are fairly expensive to make, but are extremely fuel efficient. They run off any furnace fuel. Since you'd need to create a lot of these fairly expensive boilers to get much steam, they're not recommended for use.

Finally, Gregtech adds multiblock large boilers. The first one, the large bronze boiler, is available at late LV (as soon as you have MV circuits), up to the large tungstensteel boiler available at IV. These run off (extremely large quantities of) any furnace fuel or flammable liquid. Running these off liquids is not really viable- Railcraft boilers run off creosote more efficiently, while most any other flammable liquid is better in a generator of some kind. These produce enormous amounts of steam, 16000L/s (400 EU/t) for a bronze boiler and even more for higher tier ones. They also consume extremely large quantities of fuel, so be prepared. They're extremely good for producing large amounts of steam from furnace fuel, but Railcraft boilers are more efficient for using creosote.

Obtaining Fuel: Boilers require fuel to run, the two most common being charcoal and creosote oil.

Used in: Steam Turbines Remember that each steam turbine has an efficiency percentage, which will affect the EU/t values listed above.

Oil
Oil is the most common fuel used LV-HV. It's available mid-LV, and is viable until EV for power generation and useful for other resources far beyond that. Oil itself is not recommended to be used as a fuel, instead it must be refined. The four main fuels obtained from oil, in order of complexity, are light fuel, diesel, cetane-boosted diesel, and high-octane gasoline. Each one is more oil-efficient, complex, and a higher tier than the last. Oil can also be distilled into various useful chemicals- ethylene for polyethylene, a plastic, toulene for explosives, etc., but this guide is focusing on energy production.

Production: Oil is pumped out of the ground through either pumps on physical oil wells, or oil drilling rigs on bedrock. It is then refined through a process of distillation and refining into four "base" fuels. From there, these base fuels can be cracked, distilled, refined, and mixed into various more complex hydrocarbons or burned directly.

Pumping: There are physical geysers of oil that spawn on the surface. A pump placed on top of these will bring up the oil, which sits in an underground reservoir, when it is fed power and mining pipes. Oil drilling rigs, first available in MV, extract oil from hidden reservoirs under the bedrock, which can be found using prospector's scanners or a seismic prospector.

Distillation and refining: Oil can then be distilled into four primary distillates, in various fractions based on what type of oil it is. A distillery lets you pick one of the four fractions, while a distillation tower creates all four at once. Once the oil has been turned into a fraction, the fraction must be de-sulfurized by mixing it with hydrogen(can be easily obtained by electrolyzing water) in a chemical reactor. The four fractions are light fuel, heavy fuel, naphtha, and refinery gas. Until you obtain a distillation tower, the only two you need to worry about for power generation are light fuel and heavy fuel.

Making Higher Tier Fuels: Light fuel can be burned directly for a respectable amount of EU, available at LV. At MV, you can mix light fuel and heavy fuel in a 5:1 ratio to obtain diesel. At HV, you can mix this diesel with tetranitromethane- made using nitric acid and ethenone in a chemical reactor- to get cetane boosted diesel. At EV, there is an extremely complex set of mixer recipes to obtain high-octane gasoline (regular gasoline can be made at HV but isn't worth using). Each tier is more complex than the last, but more oil-efficient. Light fuel is still a viable source of power even at EV, but at that point making cetane-boosted diesel will double your power output per cell. Once you obtain a distillation tower, the naphtha and refinery gas can be steam-cracked or hydro-cracked to obtain more light fuel or heavy fuel, or made into various chemicals for use in other applications.

Used in: Combustion Generators

Bio Diesel
Bio diesel is a renewable combustion generator fuel made primarily from plants. It has three ingredients and, like regular diesel, can be cetane-boosted for better efficiency. It can be made in LV, but most methods of farming it in decent quantities require MV.

Production: Bio diesel is made out of seed oil or fish oil, ethanol or methanol, and sodium hydroxide.

Seed oil can be obtained from most plants, but the best candidates are peanuts or sesame seeds from Pam's Harvestcraft, or hazelnuts from Extra Trees(Forestry addon). The best ways to farm these are generally the Forestry multifarm or the Ender IO Farming Station. To obtain seed oil, place these in a fluid extractor. Fish oil can be obtained from fish, which can be obtained in bulk from GT++ Fish Catchers or the GT++ Fishing Port multiblock.

Ethanol can be made from distilling forestry biomass (more efficient) or fermented biomass. These can be obtained by compressing plants into plantballs, making that into bio chaff, and putting the bio chaff into either a brewing machine, fluid canning machine, or pyrolyse oven (in order of efficiency) and fermenting, or by putting the bio chaff into a chemical bath to make mulch, and putting that into a brewing machine or pyrolyse oven. Methanol can be made from carbon monoxide or carbon monoxide plus hydrogen in a chemical reactor, or distilled from fermented biomass. It's less efficient than ethanol to make from biomass, but can be made from chemicals.

Sodium hydroxide can be made by distilling salt water, or by mixing sodium and water in a chemical reactor. It's the hardest to make renewable, since you need sodium or salt, but you only need small quantities of it (one dust can make 54 cells of bio diesel)

These 3 ingredients are then mixed together in a chemical reactor. From there, it can be burned directly or, once HV is reached, mixed with tetranitromethane(nitric acid and ethenone in a chemical reactor) to get cetane-boosted diesel.

Used in: Combustion Generators

Nuclear Reactors
Available as soon as you've reached the Moon (late HV-early EV), nuclear reactors are a strong power source for EV and IV. The process of creating a reactor is quite complex and risks huge nuclear explosions. You are strongly advised to try all designs in a reactor planner before using them, and to encase your reactors in reinforced stone to prevent explosions. Documentation on reactors is rather spotty, you can ask questions in the GTNH discord.

Fuel: The main fuels used in a nuclear reactor are thorium, uranium, and MOX. Naquadah and naquadria rods are also available, acting like uranium and MOX rods, respectively, with longer lifetimes.

Thorium is the cheapest and easiest to obtain, obtainable in large quantities from coal ore or thorium ore found in the nether. It lasts a long time but doesn't make much power.

Uranium is obtained at Mars tier from uraninite ore. It doesn't last as long as thorium, but makes more power.