UnOff. Factorio FAQ: Energy and Power

Frequently Asked Questions

for the computer game

Factorio

(UnOfficial FAQ: Energy and Power)

www.factorio.com

(official link, though)

Link back to the index.

Q: What's all that with energy and power and units and prefixes? How is "energy" different from "power"?

A: There are two terms you need to understand here:
Energy and power.

Energy is an amount of work that you can have performed or that needs to be performed. It's measured in joules, J.

Power is the rate at which work is performed, or the rate at which potential work is becoming stored as energy. It's measured in watt, W. Thus 1 watt is the same as 1 joule per second, 1 W = 1 ^J/_s.

1 joule, and likewise 1 watt, is a tiny amount of energy/power, and so the game often deals with thousands or millions of them at a time.

The main prefixes used in the game are k for kilo (thousands, 10³), M for mega (millions, 10⁶) and G for giga (billions, 10⁹). Higher prefixes might or might not be used in the game, I'm not sure, but the devs are generally scientifically correct, so if so they'd be using T for tera (million millions, 10¹²) and P for peta (million billions, 10¹⁵), and then I'd actually have to look it up because I don't offhand remember what comes after P.

Your Steam Engines and your Solar Panels output power. Your machines (Inserters, Assembler Machines, Laser Turrets...) consume power.

Your Accumulators store energy. The Accumulator in the vanilla game, the Basic one, can store 5 MJ of power, 5 million joule. It can discharge or recharge at a power rate of 300 kW, 0.3 million joule per second.

Therefore it'd take a bit more than 15 seconds (5 million joules divided by ¹/₃ million joules per second equals 15 seconds, but it's actually a bit less than ¹/₃ million, thus actually a bit more than 15 seconds exactly 16 seconds) to fully discharge or fully recharge an Accumulator at maximum rate.

Finally, you might wonder why I'm sometimes talking about electrical energy vs chemical energy.

That's fairly simple, though. In the context of Factorio (outside of this context, it's more complicated, but only a bit) chemical energy means something that you can burn. Mainly Wood, Coal or Solid Fuel. When you burn something (recreational uses aside), it is usually because you want to convert the chemical energy into thermal energy, heat. Sometimes you just want to heat your home because it'd be freakin' cold otherwise. Other times, you want to use that heat to drive some kind of turbine system to convert the thermal energy into electrical energy, because electrical energy is very convenient for many reasons, including being fairly easy to move over moderate or long distances (that is, you have centralized production of electrical energy, then distributing that energy out to many different consumers of electrical energy). Or into kinetic energy to make your Car or Tank move.

Some mods offer additional ways to store energy (usually just better Accumulators - I fear that some mods end up being a bit cheesy here), or additional ways to produce thermal energy (e.g. the Uranium Power mod) that can then be used to produce electrical energy in Steam Engines.

sapientius, non contentius labora

Q: Why is it considered bad to use Electric Furnaces? The idea of not needing to use Belts to move in the Coal sounds very appealing, as it simplifies logistics immensely.

A: The problem here is that you still need to burn the Coal (or some other combustible, such as Solid Fuel or Wood) to smelt the Iron Ore or Copper Ore - you just burn it in a faraway Boiler connected to Steam Engines, instead of directly in the Furnace. And then you move the electricity from the Steam Engines to the Electric Furnace. And while Stone Furnaces and Steel Furnaces ae 100% efficient, converting all the chemical energy into thermal energy (heat to smelt the stuff in the Furnace), Boilers are only 50% efficient, so you need twice as much fuel, in net terms, if you use Electrical Furnaces instead of Stone or Steel Furnaces (and with twice as much fuel meaning twice as much Pollution).

That might not be a problem for you, of course. And later in the game you may have transitioned almost completely to Solar power, where your Steam Engines are only used for emergency power when large parties of hippie aliens comes a-visiting simultaneously and causing your Laser Turrets to draw more electricity than your Accumulators can provide.

So it's not always bad to use Electric Furnaces. You just need to be aware of the consequences. And yes using Electric Furnaces does simplify the logistics. I agree that it's a pain in the ass to have to Belt in Coal (or Solid Fuel) to your smelting areas.

sapientius, non contentius labora

See also under Common Problems about why it might seem as if your Steam Engines aren't working (or your Boilers aren't being re-fueled).

Peter34