Subnautica 2 Power Guide — Solar vs Thermal vs Bioreactor vs Hydroelectric

Power Basics

Every module in your base draws power. If total consumption exceeds generation, your base goes dark, no oxygen, no fabricator, no lights. Here's how to never let that happen.

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Power Source Comparison

| Source | Power Output | Cost | Maintenance | Best Depth | |--------|-------------|------|------------|------------| | Solar Panel | 50 (daytime) | Low | Zero | 0-50m | | Bioreactor | 500 (fuel-based) | Medium | Refuel every 30-60 min | Any | | Thermal Plant | 250 (constant) | High | Zero | Hot zones only | | Hydroelectric Turbine | 200 (current-based) | Medium | Zero | Currents only |

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Solar Panels, The Early Game Standard

Best for: Your first base in the Shallows.

Pros: Free, infinite, zero maintenance. Build once, forget.

Cons: Useless at night. Efficiency drops with depth. Below 50m, output is negligible.

Optimization:

• Build 3-4 panels for a basic base (Room + Fabricator + Moonpool).
• Add Power Storage to bank daytime energy for nighttime use.
• At 50m+, switch to Bioreactor or Thermal.

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Bioreactor, The Universal Backup

Best for: Any depth. Great as a secondary/backup power source.

Pros: Works anywhere. Accepts any organic material as fuel.

Cons: Needs constant refueling. Empty Bioreactor = zero power.

Best fuel sources (ranked by efficiency):

1. Excess fish from aquarium breeding (infinite, renewable)
2. Plant matter from growbeds (infinite, renewable)
3. Hoverthorn (high energy density)

Optimization:

• Pair with an aquarium for infinite fish fuel.
• Use as the backup to Solar or Thermal, not the primary source.
• Build a small locker next to the Bioreactor with emergency fuel.

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Thermal Plant, The Endgame King

Best for: Hot Caves, Hydrothermal Vents, deep Karakorum zones.

Pros: Infinite, constant, highest output per plant. Zero maintenance.

Cons: Only works near heat sources. Requires Heat Tolerance to reach the build site.

Where to build:

• Inside Hot Caves under Tailings Village
• Near thermal vents in Karakorum
• Near lava flows in Hydrothermal Vents

Optimization:

• One Thermal Plant powers a large base. Two powers everything forever.
• Use Power Transmitters to send energy from a distant Thermal Plant to your base.
• Build the Thermal Plant first, then run transmitters back to your base location.

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Hydroelectric Turbine, The Niche Pick

Best for: Bases built near water currents.

Pros: Constant output while current flows. No fuel.

Cons: Location-dependent. You can't move the current, you must build near it.

Good current locations:

• Camp One (Jelly Barrens)
• Near Tufa Towers
• Axum Observatory (Karakorum)

Optimization:

• Requires Power Transmitters to connect to your base.
• Currents are easy to spot, look for visible water flow lines and floating particles.

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Power Storage, Don't Skip This

The Power Storage module (1× Germanium Ingot, 3× Titanium, 2× Salt) banks excess energy.

Why it's essential:

• Solar panels produce 0 at night. Storage bridges the gap.
• If your Bioreactor runs dry, storage gives you time to refuel.
• During peak demand (charging 2 Power Cells + running Fabricator + Moonpool), storage prevents brownouts.

Build at least 1 Power Storage per base. Late-game bases benefit from 2-3.

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The Optimal Power Setup by Stage

Early Game Base (Shallows)

3× Solar Panel + 1× Bioreactor + 1× Power Storage

Solar handles daytime. Bioreactor covers nighttime. Storage smooths the transition.

Mid Game Base (Hot Caves / Karakorum Edge)

1× Thermal Plant + 1× Bioreactor (backup) + 2× Power Storage + Power Transmitters

Thermal is infinite once built. Bioreactor is insurance.

Late Game Base (Deep Karakorum)

2× Thermal Plant + 2× Power Storage

Two Thermals power everything forever. No Bioreactor needed at this stage.

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Related Guides

• base building guide
• resource guide
• beginner's guide

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Power Troubleshooting

| Problem | Likely Cause | Fix | |---------|-------------|-----| | Base dark at night | No Power Storage with Solar panels | Build Power Storage | | Bioreactor always empty | Fuel consumption too high | Add Solar/Thermal as primary source | | Thermal Plant not working | Too far from heat source | Move closer to vent/lava | | Turbine not spinning | No water current present | Relocate base or switch power source | | Everything flickering | Power draw exceeds generation | Add more generation OR build Power Storage |