Effects of variable load on Power Station
The need for additional equipment
The variable load on a power station necessitates having additional equipment. By way of illustration, consider a steam power station. Air, coal, and water are the raw materials for this plant.
- In order to produce variable power, the supply of these materials will be required to be varied correspondingly.
- For instance, if the power demand on the plant increases, it must be followed by the increased flow of coal, air, and water to the boiler in order to meet the increased demand.
- Therefore, additional equipment has to be installed to accomplish this job.
Increase in production cost
- If a single alternator is used, it will have poor efficiency during periods of light loads on the plant.
- Therefore, in actual practice, a number of alternators of different capacities are installed so that most of the alternators can be operated at nearly full load capacity.
Effect of Variable Load on Power Plant Design
- Variable load results in fluctuating steam demand. Due to this, it becomes, very difficult to secure good combustion since efficient combustion requires the coordination of so many various services.
- The variable load requirements also modify the operating characteristics built into equipment. Due to non-steady load on the plant, the equipment cannot operate at the designed load points. Hence for the equipment, a flat-topped load efficiency curve is more desirable than a peaked one.
Effect of Variable Load on Power Plant Operation