Sources

Six generation sources feed the DC Bus: Human Power, Solar, Wind, Hydro, Ocean, and Geothermal. All energy sources except Human Power unlock through the research progression chain. Total kWh generated does not gate Wind, Hydro, Ocean, or Geothermal.

Generator units

Every generation source except Human Power is a fixed field of unit slots — one slot per potential generator, up to that source’s unit cap (for example, Solar has 50 slots). Each slot is an independent unit: it is bought, upgraded, repaired, and degrades on its own.

• Purchase: an empty slot is always filled with a tier 1 unit of that source, at the tier 1 price. Higher tiers can never be bought directly.
• Upgrade: an owned unit upgrades one tier at a time (tier N → N+1) at the full price of the target tier. Generator research level N unlocks tier N+1 as an upgrade target. Upgrading preserves the unit’s condition (effectiveness) and its site variance.
• Site variance: each unit rolls a permanent output multiplier when its slot is first purchased, representing site quality (shading, terrain, geography). Solar sites are nearly uniform; later sources roll wider bands. The multiplier survives upgrades and repairs; it is the slot’s roll, not the equipment’s.
• Condition: each unit degrades individually and shows its own condition bar. A per-unit Repair action restores that unit to 100%. See Degradation and maintenance.

A unit’s output is tier output × condition × site variance, then the source-wide charge controller, weather, and storm multipliers apply as usual.

One shared charge controller per generation source limits total generation from that source. Human Power bypasses charge controllers. When a new generator type unlocks, its starter DIY Resistor charge controller unlocks immediately.