How much steam does a 100 MW steam turbine need at full load?

A 100 MW steam turbine requires 360 tonnes per hour of steam if each kilogram delivers 1,000 kJ of electrical energy at the generator terminals. If that effective energy yield is lower, steam demand rises; if it is higher, demand falls. This is a calculation example, not a universal rating. A defensible full-load flow requires inlet steam conditions, exhaust pressure, turbine efficiency, and a clear definition of what the 100 MW output includes.

The first selection question is therefore whether the proposed steam system can sustain the required flow at the specified turbine inlet conditions. Boiler capacity alone cannot answer it: pressure losses, process steam withdrawals, extraction duties, and condenser performance all affect the steam available for power generation.

Calculate flow from the energy delivered per kilogram

For a simple turbine with one inlet and one exhaust, without extraction or reheat, the preliminary relationship is:

Steam flow (kg/s) = electrical output (kW) ÷ [(h₁ − h_2s) × η_is × η_m × η_g]

Here, h₁ is inlet enthalpy and h_2s is the exhaust enthalpy after ideal, constant-entropy expansion to the specified exhaust pressure. Both are expressed in kJ/kg. The