Enter your electricity demand in MWh per day, and your heat demand in GJ per day if you play with seasons. The calculator compares every power plant the wiki lists, then sizes your chosen heating plant and adds its own electricity use to the power demand. Inputs stay in the address bar, so a plan can be bookmarked or shared.
Finding your demand
For a new city, the citizen consumption calculator gives the housing load and links straight here with it filled in. For industry, the production chain calculator totals the power of every building in a chain. Add the two. In a running game, the in-game statistics give your actual consumption, which already includes shops, schools and services.
Comparing the plants
Figures are the wiki's listed daily production. A coal power plant makes 1,400 MWh a day from 24 t of coal with 20 workers. A gas power plant makes 1,050 MWh from 8.8 t of oil with 15 workers. A solar plant makes 560 MWh with 8 workers and no fuel. The wind turbines need no workers at all but make only 15 MWh (small) and 35 MWh (big), and the real output depends on wind. The single reactor nuclear plant makes 4,680 MWh from 0.04 t of nuclear fuel a day, but needs 20 workers with higher education on top of 40 regular workers.
The Net column subtracts each plant's own listed energy use, which matters most for the gas plant (3.4 MWh) and the nuclear plants (7.8 and 9.6 MWh). The fuel-per-year column is the number to check against your mines or your import budget. Ten coal plants burn 87,600 t of coal a year, 240 t a day, which takes two coal processing plants and about half the output of a fully staffed coal mine.
Heating plants
With seasons on, flats, shops and schools need heat. The wiki lists the heating plant at 210 GJ a day from 8.4 t of coal (30 workers) and the small heating plant at 42 GJ a day from 2.1 t of coal (7 workers). The big plant also draws up to 63 MWh of electricity a day, so ten of them add 630 MWh to your power demand. The calculator adds that for you. The wiki does not list heat demand per building in GJ, so read your heat need from the game rather than from population.
Substations
A substation can feed about 2.35 MW to buildings within 325 m, according to the wiki's electricity page. The calculator divides your average draw by that to give a minimum substation count. Peak load is higher than the daily average, and range limits mean a spread-out city needs more, so treat it as a floor.
The spare capacity box adds a margin to both power and heat. Ten percent covers small growth; raise it if you plan to export electricity or expect a new district soon.
Nuclear fuel: making your own
A single reactor plant burns 0.04 t of nuclear fuel a day for 4,680 MWh. That fuel takes three plants of its own, from the wiki's resource pages: a uranium processing plant (36 t of uranium ore into 1.7 t of uranium oxide), a uranium conversion plant (2.0 t of oxide and 0.21 t of chemicals into 0.96 t of UF6) and a nuclear fuel fabrication plant (0.40 t of UF6 and 0.75 t of chemicals into 0.095 t of fuel). One fabrication plant at full output covers more than two single reactors.
The production chain calculator sizes the whole nuclear fuel chain for any daily amount. The wiki lists no worker counts for the three fuel plants, so its worker total only covers the chemical plants and raw inputs.
Questions
How much power does one coal plant make?
1,400 MWh a day from 24 t of coal with 20 workers, per the wiki's electricity page. That is 8,760 t of coal a year.
How many houses does one coal plant power?
At about 0.06 MWh per resident per day in large blocks, one coal plant covers roughly 23,000 residents' homes, before shops, services and industry.
Can I sell electricity?
Yes, but not at the customs house. The wiki's trade page says electricity is only imported or exported through electrical connections at the border, where you choose the direction yourself.
Why does the heating plant add to my power demand?
The big heating plant uses up to 63 MWh of electricity a day and the small one 12 MWh, so ten big heating plants add 630 MWh. The calculator adds this for you.
Is solar worth it?
A solar plant makes 560 MWh a day with 8 workers and no fuel, but nothing at night, so other plants have to carry the load after dark. Treat it as a daytime supplement.