Fuel Cell

Fuel Cells are stored energy. They are generated from Fusion Reactor output once you unlock Fuel Cell Technology, and they power several late-game systems that normal resources do not.

What Fuel Cells Do

Fuel Cells are used for three main jobs:

powering some moon infrastructure
boosting certain fleet missions
acting as a tradable resource on the Exchange

Unlike Energy, Fuel Cells are stored. You can save them, transport them, trade them, and spend them later.

How Fuel Cells Are Generated

Fuel Cells only charge if:

you have Fuel Cell Technology level 1 or higher
your planet has active Fusion Reactor output

The charge formula is:

fuel_cells_gained_per_hour = effective_fusion_output_per_hour / 80

What "Effective Fusion Output" Means

The game first calculates your Fusion Reactor output, including:

the reactor's level
the reactor's current production slider
Energy Technology bonuses
Fusion research bonuses

That final output is then converted into Fuel Cells at 1 Fuel Cell per 80 Fusion output per hour.

Important: the Fusion Reactor does not power your live energy grid. Its output is converted into Fuel Cells instead.

Fuel Cell Drain

If your planet has a live power deficit, Fuel Cells drain to cover it.

fuel_cells_lost_per_hour = negative_energy_per_hour / 1000

So if your planet is short by 5,000 Energy per hour, it drains:

5 Fuel Cells per hour

Fuel Cell Storage

Fuel Cell storage is calculated from two parts:

base_storage = max(5,000, energy_max × 12)
fusion_bonus = floor(metal_storage_capacity_at_same_fusion_level / 10)

total_fuel_cell_storage = base_storage + fusion_bonus

Plain-English Version

Every world gets at least 5,000 Fuel Cell storage.
High-energy worlds naturally store more because storage scales with energy_max.
Every Fusion Reactor level also adds a storage bonus based on one tenth of the Metal Storage capacity formula at that same level.

That is why Fuel Cell storage grows much faster once you start investing in Fusion.

Moon Infrastructure Costs

Fuel Cells are consumed directly by some moon features:

Sensor Phalanx: 2 Fuel Cells to open a scan, then free refreshes for 5 minutes while that report window stays open
Jump Gate: 200 Fuel Cells per jump from the source moon

If you are planning heavy moon utility use, Fuel Cell stockpiles matter.

Daily Usage Cap

Players can spend up to 500 Fuel Cells per calendar day total across the capped Fuel Cell spend paths. That shared cap includes:

reward-style mission boosts
Sensor Phalanx scans
Jump Gate activations

Speed-boost launches still spend Fuel Cells normally, but they do not count against this daily cap.

You can still stockpile, trade, and transport more than that. The cap only limits how many Fuel Cells can be consumed through the capped systems in a single game day.

Mission Boosts

Fuel Cells support two different mission-boost systems.

Speed Boost Missions

These missions can spend Fuel Cells to double the selected travel speed:

Transport
Deployment
Harvest
ACS Defend

The launch cost is:

fuel_cell_cost = max(25, ceil(normal_deuterium_cost / 100))

If you pay it:

the fleet travels at double the selected slider speed
the mission's normal deuterium fuel cost becomes 0
the Fuel Cells spent on that launch do not count against the shared daily cap

Reward Boost Missions

These missions can spend Fuel Cells to improve rewards:

Patrol
Trade
Recon
Exploration

Exploration resource and ship finds use this multiplier:

reward_multiplier = 1 + min(5, fuel_cells_spent / 100)

That creates these tiers:

Fuel Cells Spent	Reward Multiplier
0	1x
100	2x
200	3x
300	4x
400	5x
500	6x

Important: reward-style mission boosts share the same 500 Fuel Cells per calendar day player cap with Sensor Phalanx scans and Jump Gate activations.

Mission-specific effects:

Patrol: more debris from successful patrol combat, capped at 2x total debris from the Fuel Cell boost, and it does not increase hostile Patrol encounter size
Trade: spends up to 100 Fuel Cells for up to 6x on the mission's random +1% to +25% trade bonus on each successful tick instead of multiplying the full conversion amount
Recon: larger hidden-debris, embezzlement, and defection amounts, plus a higher per-tick chance to reveal the active Patrol, Trade, Recon, and Exploration holds in that system, up to 25% at 500 Fuel Cells; it does not add target slots or improve report-roll odds
Exploration: more resource finds and ship-find value at the normal reward multiplier, while hostile encounter debris gets only up to 2x from the Fuel Cell portion of the bonus; Fuel Cells still do not make hostile encounter fleets larger

Beginner Advice

Fuel Cells are not just for moon play. They are also a deep-space mission economy resource.
If you are short on Fuel Cells, check your live Energy balance first. A power deficit quietly drains them.
Fusion Reactor investment is both production and storage investment for Fuel Cells.
If you do not yet understand the travel side, read Fleet Mechanics before spending large Fuel Cell boosts.