Hearts of Iron IV’s Open Beta Adds Power Plants and Factory Energy Costs
Factories and production lines now feed a national power pool, where spare capacity and oil-rich states can affect industrial output.
Hearts of Iron IV is testing a new energy system in its open beta, tying factory output to a country-wide balance of power supply and demand. An Oct. 7 Steam announcement details the latest changes, including state-level power plants, energy costs for production lines, and bonuses for maintaining spare capacity.
Power plants now take up a state building slot rather than competing for shared factory slots, and each state can have up to three levels. Their output depends on local terrain, dams, and oil resources. Civilian factories, military factories, and dockyards also generate some power, while coal is burned only when needed.
Production lines now draw energy, with costs broken down by category. In a Germany example set in early 1940, the country needs 897.5 energy and has all of its demand supplied, with generation at 1,130.3. Its spare-capacity bonus reaches 100%. The threshold for that bonus depends on a country’s total factories, so smaller nations can reach it earlier in a campaign.
Aircraft account for the largest share of Germany’s production energy costs in the example, with tanks and gun production also drawing power. The new MIO policies add another tradeoff: Electrified Assembly raises energy use in exchange for production-efficiency bonuses. Its shown tooltip lists a 25% increase in production energy draw, a 5% efficiency-cap bonus, and a 10% efficiency gain.
Power plants are also more vulnerable to strategic bombing, but countries with enough spare capacity can repair them faster. Oil remains focused on fueling armies rather than being burned for energy, though oil-rich states now improve power plant output. The design gives smaller countries more reason to specialize and invest in infrastructure. For example, moving Hungary to War Economy means building power plants first.
The open beta is not translated and has no new art assets yet. Paradox is asking players to try it and share campaign feedback.
Hearts of Iron IV Energy Rework Patch Notes
- Added a country power pool: demand comes from production line power draw, supply from factories and power plants; the supply/demand ratio drives the factory energy buff & debuff
- Added Power Plants as an upgradeable state-level building. Output depends on the state (terrain, oil, dams)
- Dockyards, civilian and military factories now generate some power
- Dams now matter for power generation, and were reassigned dam types. Added new massive dams
- Spare power now grants a surplus bonus, and oil states boost power plants
- Coal is only burned when needed
- Production lines now have an energy cost, with a tooltip breakdown per category (air, naval, land)
- Added power generation/consumption modifiers; removed the old energy building
- MIOs: added a production energy draw stat, with Electrified Assembly and Power Rationing policies
- Added a research tech related to power
- Industrial focus branches in most focus trees now reward power plants
- Added 1936 & 1939 starting power plant setup for the world
- Topbar power bar, lack-of-power alert and tooltips now use the power pool, listing generation per source, power plant states, coal usage and maximum generated power
- Technology and trade window now supports coal and oil burning
- AI builds power plants as needed
- Missing: New art for the various icons
Which part of the energy system do you think will have the biggest effect on your campaigns? Follow the open beta’s progress on X, Bluesky, YouTube, Instagram, Steam, and Telegram.
