Power is the heartbeat of every Factorio factory. Belts stall, inserters freeze, and laser turrets go dark the instant your grid can’t keep up with demand. Getting power right means understanding the exact ratios that turn fuel and water into megawatts — and in Factorio 2.0, one of the most important of those ratios changed. This guide covers steam, solar, accumulators, and brownout management in depth, with every number verified against the official wiki, and it flags exactly where old 1.1-era advice will now lead you astray.
If you’re running a shared map and want a grid that never browns out for your friends, a dedicated box matters as much as good ratios — you can spin up a managed Factorio server in a couple of minutes and stop worrying about your home PC tanking the simulation.
Version context: 2.0 and Space Age
Factorio 2.0 (a free base-game update) and the paid Space Age expansion both launched on October 21, 2024. As of 2026, the 2.0.x line is the current stable release; 1.1 was the previous multi-year stable line. Space Age adds four new planets (Vulcanus, Fulgora, Gleba, Aquilo), space platforms, the quality system, elevated rails, and new science. Most stats below are quoted at normal quality — higher quality tiers (uncommon through legendary) scale machine stats, but quality is a 2.0-only mechanic that did not exist in 1.1.
The single most important takeaway for power: the offshore-pump-to-boiler ratio changed in 2.0. If you copy a steam build from a pre-2024 guide, you’ll massively under-build your water supply. We’ll get to exactly why below.
Steam power: boilers and steam engines
Steam is your starting power source and remains a perfectly valid backbone deep into the game. The chain is simple: an offshore pump pulls water, a boiler burns fuel to heat that water into steam, and a steam engine converts the steam back into electricity. Getting the ratios right means no machine is ever starved or idle.
The core numbers
- Boiler: consumes 1.8 MW of fuel energy. It uses 300 kJ to convert 1 water into 10 steam at 165 °C.
- Steam engine: produces a maximum of 900 kW and consumes 30 steam per second at full output.
- Boiler-to-engine ratio = 1 : 2. One boiler produces enough steam to fully drive two steam engines. This ratio is unchanged between 1.1 and 2.0.
The math is clean: one boiler turning out 10 steam per unit of water, at the throughput a 1.8 MW heat draw allows, feeds two 900 kW engines for a tidy 1.8 MW of electrical output per boiler pair. Build in repeating blocks of 1 boiler and 2 engines and you’ll never have a mismatched steam line.
⚠ The 2.0 offshore-pump ratio change
Here is the trap. In Factorio 1.1, the famous steam ratio was 1 offshore pump : 20 boilers : 40 steam engines, which delivered roughly 40 MW. Countless older guides, forum posts, and YouTube tutorials still cite this. It is wrong for 2.0.
The 2.0 fluid rework changed the offshore pump’s output. It now pushes 1200 water per second. Because the water-to-steam conversion is 10:1, that single pump can now feed a vastly larger steam plant. The new optimal ratio is:
Factorio 2.0 steam ratio:
1 offshore pump : 200 boilers : 400 steam engines ≈ 360 MW
Factorio 1.1 (OLD — do not use in 2.0):
1 offshore pump : 20 boilers : 40 steam engines ≈ 40 MWSo in 2.0, a single offshore pump supports ten times the boiler-and-engine count it did in 1.1. The boiler-to-engine relationship inside the build (1:2) stayed the same; only the water source got dramatically more powerful. If your steam plant keeps browning out despite plenty of boilers, the old habit of dropping one pump per ~20 boilers will leave you starved — though in practice the bigger risk now is the opposite: people over-build pumps out of habit. Either way, know the real number is 1:200:400.
| Component | Key stat | Notes |
|---|---|---|
| Offshore pump | 1200 water/s (2.0) | The number that changed; drives the new 1:200:400 ratio |
| Boiler | 1.8 MW fuel; 300 kJ → 10 steam/water at 165 °C | Burns wood, coal, solid, rocket, or nuclear fuel |
| Steam engine | 900 kW max; 30 steam/s | 1 boiler feeds exactly 2 engines |
| Steam plant total | ~360 MW per offshore pump | 200 boilers + 400 engines |
Solar panels and accumulators
Solar is the late-game dream: zero fuel, zero pollution, and it never demands more biter defenses. The catch is the day-night cycle — panels make nothing at night, so you must pair them with accumulators that charge during the day and discharge after dark.
- Solar panel output: 60 kW in full daylight, but only ~42 kW averaged across a full Nauvis day/night cycle (it spends part of the cycle in dawn, dusk, and darkness producing less or nothing).
- Optimal ratio: approximately 25 solar panels : 21 accumulators, which works out to ~0.84 accumulators per panel. The precise wiki figure is 0.84672 accumulators per panel (equivalently 2646 accumulators : 3125 panels) for fully sustained, round-the-clock power.
The intuition behind 25:21: during the day, panels must power your factory and charge the accumulators enough to carry the whole night. Size the panel field for both jobs and the accumulator bank to store one night’s worth of demand, and the system self-balances forever. Lay it out as a repeating tile of 25 panels to 21 accumulators and scale it up linearly.
Space Age flag: the 25:21 ratio is Nauvis-specific. Other planets have different day lengths and solar multipliers, so this figure does not transfer to Vulcanus, Fulgora, or the other worlds. On Fulgora, for example, you’ll lean on lightning collectors and accumulators rather than solar at all. Recompute (or check the planet’s day-length) before relying on solar off-world.
Brownouts, accumulator buffering, and the power switch
Factorio’s grid shares power proportionally across all consumers. When supply drops below demand, the entire network slows down at once — this is a brownout. Your inserters move sluggishly, assemblers crawl, and laser turrets struggle to fire just when a biter wave hits. Because everything degrades together, a brownout can quietly cascade: slower power-line construction means slower repairs, which can spiral.
Reading the problem
Click any power pole to open the electric network info screen. It shows total production versus consumption and a per-category breakdown of who’s drawing what. If the satisfaction bar isn’t pinned at 100%, you’re either browning out now or about to. This screen is the first place to look before adding generators blindly.
Accumulators as a buffer
Accumulators do more than store solar energy. They absorb demand spikes — a sudden burst of laser-turret fire or a fleet of construction robots all charging at once. By keeping a charged accumulator bank on your main grid, short spikes draw from stored energy instead of instantly outrunning your generators. They are the shock absorber of your power network.
The power switch + accumulator backup pattern
The classic reliability trick is to run solar as your primary source and keep a steam backup that only fires when solar can’t cover demand. You wire it with a power switch gated by an accumulator charge circuit condition:
- Connect an accumulator to a wire and read its charge percentage (the [A] signal).
- Wire that signal into a power switch that connects your steam plant to the main grid.
- Set the condition so the switch closes (turns steam on) when accumulator charge falls below a threshold — say, 20% — and opens again once solar has recharged the bank above a higher threshold.
This way your boilers sit idle (burning no fuel) on sunny surplus days and automatically kick in only during the night or a demand spike that solar can’t meet. It’s the cleanest way to combine renewable efficiency with steam’s reliability and avoid brownouts entirely.
When to use each power source
- Steam: your starter and your backup. Fast to build, scales linearly, and the new 1:200:400 ratio makes large steam farms cheap to plan. Downside: burns fuel and produces pollution that aggravates biters.
- Solar + accumulators: zero ongoing fuel and zero pollution, ideal as your steady-state main grid once you can afford the footprint. The 25:21 ratio guarantees 24-hour coverage on Nauvis.
- Nuclear: enormous, compact output for mid-to-late game. A single reactor produces 40 MW of heat and gains +100% per adjacent active reactor, so tight 2×N arrays multiply output dramatically. If you’re scaling past what steam comfortably handles, our nuclear mining and power guide covers the full uranium-to-turbine chain.
Most successful factories layer all three: steam to bootstrap, nuclear or solar for the bulk, and a switched steam backup behind an accumulator bank to catch the gaps.
Pollution, biters, and your power choice
Power generation isn’t just an engineering problem — it’s a combat one. Boilers produce pollution, and pollution is exactly what drives biter aggression: enemies stay passive until your pollution cloud reaches their nests, at which point spawners spend that pollution to muster attacks. A sprawling steam farm can therefore mean more frequent, larger waves. Solar and nuclear produce far less pollution per megawatt, which is part of why veterans transition off raw steam. If your power expansion is suddenly drawing waves, that’s not a coincidence — see our guide to dealing with biters for defense layouts that hold the line while you scale.
Powering your smelting and the rest of the base
Your power budget is dominated by a few heavy consumers, and smelting is usually near the top. Electric furnaces draw 180 kW each when active (with a 6 kW idle drain), versus the 90 kW fuel draw of burner-style stone and steel furnaces. A full smelting array of electric furnaces can easily eat tens of megawatts, so plan your generation around it. If you’re sizing furnace banks, our smelting guide walks through the furnace tiers and belt-saturation math in detail.
For a step-by-step walkthrough of setting up power on a hosted server — including circuit wiring and save management — the official Factorio server documentation has the panel-specific instructions.
Frequently asked questions
What is the correct boiler-to-steam-engine ratio in Factorio 2.0?
It’s 1 boiler to 2 steam engines, and this hasn’t changed from 1.1. A boiler consumes 1.8 MW of fuel and produces enough 165 °C steam to fully drive two 900 kW engines (each engine eats 30 steam/s). What did change is the offshore-pump side of the build.
Why is my old 1:20:40 steam ratio wrong in 2.0?
Because the 2.0 fluid rework changed offshore-pump output to 1200 water/s. The old 1.1 ratio of 1 pump : 20 boilers : 40 engines (~40 MW) is now a 1.1-only figure. In 2.0 the optimal ratio is 1 offshore pump : 200 boilers : 400 steam engines, producing roughly 360 MW from a single pump. Any guide still quoting 1:20:40 was written for the old version.
How many accumulators do I need per solar panel?
About 0.84 accumulators per panel — the well-known 25 panels : 21 accumulators ratio (the exact wiki value is 0.84672 accumulators per panel). That mix gives fully sustained day-and-night power on Nauvis. Note that a panel averages only ~42 kW over a full cycle despite its 60 kW daytime peak, which is why you need so many accumulators to bridge the night.
Does the 25:21 solar ratio work on other planets?
No. The 25:21 figure is Nauvis-specific. Space Age planets have different day lengths and solar multipliers, so the ratio doesn’t transfer to Vulcanus, Fulgora, Gleba, or Aquilo. You’ll need to recompute for each world’s day-night cycle — or rely on a different power source entirely, like Fulgora’s lightning.
What causes a brownout and how do I stop it?
A brownout happens when total demand exceeds supply; Factorio then shares power proportionally and the whole grid slows down at once. Fix it by adding generation, buffering spikes with an accumulator bank, and wiring a power switch with an accumulator-charge circuit condition so a steam backup auto-fires when charge drops. Watch the electric-network info screen (click any pole) to catch shortfalls before they bite.
Is steam still viable late-game, or should I switch to nuclear?
Steam stays viable as a backbone or backup — with the 1:200:400 ratio, a single pump now supports ~360 MW of generation. But its pollution drives biter attacks, so most players transition the bulk of their load to solar or nuclear (a reactor makes 40 MW and gains +100% per neighbour in tight arrays) and keep a switched steam plant in reserve.
Nail these ratios and your factory’s power will scale as smoothly as everything else — no flickering lights, no stalled defenses, no late-night brownouts. Build steam in 1:200:400 blocks, solar in 25:21 tiles, gate a steam backup behind an accumulator-charged power switch, and your grid will outpace your demand no matter how big the base grows.
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