How much electricity does an electric steelworks need, hour by hour?

Annual energy = liquid steel × (arc furnace + ladle furnace + auxiliaries) + products × (rolling + electric reheating), with liquid steel = products ÷ 0.94. With the default values (450 + 70 kWh/t of liquid steel, 37.5 of it for the ladle furnace; 110 + 300 kWh/t of product) the model returns the 289 GWh a year of the RC-1 reference configuration for Phase 1 and, over 8,000 operating hours, its average load of 36.1 MW.

The typical day is the one in White paper 05 (Chapter 9, Figure 9.2; method in Annex A). The arc furnace repeats its tap-to-tap cycle: bore-in, melting, recharge, bore-in, melting, refining, then tapping and turnaround, with power off for about 27% of the time. Its power varies around each step (standard deviation of 35% during bore-in, 14% during melting and 4% during refining, on a fixed pseudo-random sequence) and is capped at about 110% of the melting level. Heats follow one another after a short random delay; the ladle furnace gives one pulse per cycle; the mill, reheating and auxiliaries run steadily. Each component is then scaled so that its daily energy is exact.

Which peak? The tool quotes the 15-minute average peak, the basis on which maximum demand is billed: about 47 MW at the default values, as in the white paper. The range shown (about 16 to 51 MW) runs from the 5th to the 99th percentile of the one-minute values during operating hours. The planned maximum demand of Phase 1 is 55 MVA (45 to 65).

Two shifts. With two shifts the plant runs 16 hours on each operating day, so the hours entered (8,000 by default) become about 5,300 actual operating hours. The same annual energy is packed into them: the average over operating hours rises to about 54 MW, against 36.1 MW over the 8,000-hour basis, and the peak rises. Outside those hours only the idling auxiliaries draw power (less than 1 MW at night).

Feasibility. In Phase 1 a single furnace of the 40 t class melts all the steel: about one heat of about 40 t an hour. If the output, tap-to-tap time and operating hours entered would need much heavier heats, the tool says so: the result then describes several melting lines, not a one-furnace plant.

Limits. Generic benchmarks, not equipment ratings: the furnace power is given as an order of magnitude (about 25 MW of active power with the arc on, at the default values). No second-by-second fluctuation (flicker), no planned stoppages. The peak sizes the connection and compensation; annual energy sizes the contract. The hydro share assumes the plant receives the national mix.