Government of India has set an ambitious target of 500 GW renewable generation by 2029-30 and 175 GW by end 2022. There is a delay in capacity addition of 175 GW renewable energy sources due to covid-19 pandemic and the same may be achieved by end 2023. In near future thermal power plants (TPPs) fleet is expected to operate at an average minimum load of 40%. It shall drastically impact the schedule of most of the conventional generating plants and shall lead to operating TPPs at part load. Hence, thermal generating units shall have to be tuned such that they can meet the new load demands in a very effective and efficient manner. And if any gaps are found, the same needs to be fixed.
Looking at the addition of renewables in future, the thermal power utilities will be required to play a very important role. In this regard, a committee was constituted to guide the central, state and private utilities in selecting thermal generating units and conducting low load test. The committee would also prepare guideline for low load operation of TTPs, on the basis of experience gained from the pilot test, to help generating utilities in achieving flexibility in their units. The report prepared by the committee is expected to be beneficial for the utilities in understanding the need and implication of flexible operation of coal fired units.
Key takeaways from the report
- Immediate action needs to be taken for preparing thermal generating units for flexible operation. Initially, the pilot phase of flexibilisation/refurbishment of 11 units of central/state/private sector may be carried out for performance evaluation.
- Availability of training simulators need to be ensured for the training of operators at 40% low load operation.
- Regulation should be introduced for 40% minimum technical load operation of thermal generating units.
- Suitable regulatory mechanism, should be introduced in central and state level, wherever applicable, for the compensation.
- Keeping in mind the requirement of flexible power in future, design of new thermal units should be such that it can be possible to operate these with optimised auxiliaries, at loads lower than 40% (say 30%) without oil support and, at higher ramp rates of 2-3% in lower load range.
- Study should be initiated for finding the possibility of two shift operation of existing thermal generating units as per the grid requirement. Design of new thermal units should be such that it can be possible to operate in 2 shift mode on a regular basis.