The energy needed to start up the plant depends on the time elapsed since it was in operation and the required energy is between 200 and 1200 kWh;. The start-up phase includes the following steps:
1. Increase the pressure to 25 bar.
2. Preheat the pipes and turbine.
3. Start the turbine and reach the nominal rotating speed (100% rpm).
The energy needed to start up the plant is given by
Pstart = 1200 – 1000e(°’3°4-0-307’i°-4t2) [kWt] (8.21)