Advanced Slimefun: Reactors and Energy Systems

If you have already mastered the basic concepts of Slimefun and want to take your base to the next technological level, it’s time to understand energy systems. In this advanced guide, we explain everything about generators, reactors, energy networks, and how to optimize your electrical production to power the most potent machines in the plugin.

Understanding Energy in Slimefun

Slimefun simulates an electrical system where machines need energy (measured in Joules, or “J”) to function. Without energy, your machines will simply do nothing. The system is composed of three fundamental elements:

Generators: Produce energy.
Capacitors: Store energy.
Machines/Consumers: Use energy to perform actions.

These three elements must be connected in an energy network to function.

Energy Networks: Basic Concepts

An energy network is formed when a generator, capacitor, and/or machine are adjacent to each other (touching). Energy flows automatically from generators to capacitors and from there to machines.

Fundamental Rules

Components must be adjacent (up, down, north, south, east, west — not diagonally).
Energy is distributed automatically among machines in the network.
If the network does not produce enough energy for all machines, some will stop.
Each network works independently — there is no size limit but there is an efficiency limit.

Types of Generators

Basic Generators (Tier 1)

Solar Generator

Production: Low (only during the day).
Fuel: None — uses sunlight.
Advantage: Free and maintenance-free.
Disadvantage: Does not work at night or indoors.

It is perfect for small operations or as a complement to other generators. Place several on the roof of your base for constant production during the day.

Coal Generator

Production: Moderate.
Fuel: Coal, coal blocks, charcoal.
Advantage: Fuel is easy to obtain.
Disadvantage: Requires constant replenishment.

Lava Generator

Production: Moderate-High.
Fuel: Lava buckets.
Advantage: Lava is abundant in the Nether.
Disadvantage: Requires a bucket supply system.

Intermediate Generators (Tier 2)

Combustion Generator

Production: High.
Fuel: Oil, refined fuel.
Advantage: Higher output than basic generators.
Disadvantage: You need to refine the fuel first.

Bio Generator

Production: Moderate-High.
Fuel: Organic material (leaves, seeds, etc.).
Advantage: Fuel is very easy to obtain in large quantities.
Disadvantage: Requires automation to be efficient.

Advanced Generators (Tier 3)

Nuclear Reactor

The nuclear reactor is the crown jewel of energy generation in Slimefun. It produces massive amounts of energy but requires careful configuration.

Production: Very high.
Fuel: Uranium or Neptunium.
Coolant: Requires a cooling system with water buckets.
Risk: Without proper cooling, it can cause problems.

Setting Up a Nuclear Reactor

The nuclear reactor is the most powerful generator but also the most complex. Here is a step-by-step guide:

Materials Needed

Nuclear Reactor (crafted in the Enhanced Crafting Table with advanced materials).
Uranium or Neptunium fuel cells.
Cooling system (water buckets and coolant cells).
High-level capacitors to store the generated energy.

Installation Steps

Place the Reactor: Find a safe place for your reactor, preferably in a dedicated area.
Connect the Capacitors: Place high-level capacitors adjacent to the reactor to store the produced energy.
Load the Fuel: Insert the fuel cells into the reactor through its interface.
Configure Cooling: Ensure the cooling system is active with a constant supply of coolant.
Connect Machines: Extend the energy network from the capacitors to your machines using more capacitors as “cables”.

Reactor Maintenance

Check fuel regularly: A reactor without fuel simply shuts down.
Monitor cooling: If the cooling system fails, the reactor can have problems.
Manage waste: Spent uranium generates waste that you must store or process.

Capacitors: Storage

Capacitors are blocks that store energy and act as “cables” to extend your network. Different levels exist:

Capacitor	Storage	Recommended Use
Small	Low	Basic networks, prototypes
Medium	Moderate	Medium-sized networks
Large	High	Industrial networks
Carbonado	Very High	Massive networks with reactors

Tip: Use capacitors as “transmission lines” to carry energy to distant machines. Place them in a row connecting them to each other.

Network Optimization

Centralized vs. Distributed Network

Centralized Network: A single large generator (reactor) powers your entire base through a network of capacitors.

✅ Easy to maintain.
✅ Efficient production.
❌ If the generator fails, everything stops.

Distributed Network: Multiple small generators power independent sections of your base.

✅ Redundancy — if one generator fails, the rest keep running.
✅ Easier to expand gradually.
❌ More complex to manage.

Recommendation: For most players, a centralized network with a nuclear reactor and backup capacitors is the most efficient option.

Energy Balance

The golden rule is: your energy production must exceed your consumption by at least 20%. This gives you a margin to add new machines without having to reorganize the entire network.

To calculate your balance:

Sum the total production of your generators (J/tick).
Sum the total consumption of your machines (J/tick).
If production is greater, you are good. If not, add more generators.

Fuel Automation

A truly efficient energy network has its fuel supply automated:

For solar generators: They don’t need fuel — just make sure no blocks are blocking the light.
For coal generators: Use hoppers to feed coal automatically from a large chest.
For reactors: Set up a hopper system that automatically supplies fuel cells and coolant.

Common Mistakes

Disconnected network: If a machine is not working, check that it is physically connected to the network via capacitors.
Insufficient production: Adding more machines without increasing generation will cause some to shut down.
Misplaced capacitors: Remember that connection is only on the 6 faces, not diagonally.
Ignoring reactor cooling: This is a costly mistake that can cause the loss of fuel.
Networks too large: Very extensive networks can have distribution issues. Consider dividing into subnets.

With this knowledge, you are ready to build energy systems worthy of a nuclear engineer in Minecraft. Master energy, and you will master Slimefun!