The Generation Professionals Group is for utility professionals who work in biomass, coal, gas/oil, hydro, natural gas, or nuclear power generation fields. 


Flexible operation of thermal power plant assets

Sankaran Subramaniam's picture
Renewables evangelist Self employed

Experienced in Power sector with special focus on Renewables & Storage .  Share the sustainability story and be inspired

  • Member since 2019
  • 9 items added with 2,950 views
  • Jul 19, 2021

This post is about the flexible operation of thermal power plants as more renewables penetration occurs in the Indian electric power systems. 

On a quick note, India has about 385 GW of installed capacity of which up to 200 GW is in operation to meet the demand. India has about 96 GW of renewables in operation with an installed capacity of about 108 GW. If we include renewable assets under construction, India has achieved the target of 175 GW in renewables. 

Obviously, India has started facing a need for thermal assets to operate in a flexible mode. The nodal agency for power in the central sector has published the following guidelines for flexible operation in January 2019.

An interesting section in this report stated as follows :


9. Analysis of Critical Period in the Year 2021-22
As per prediction, highest ever renewable generation of 108926 MW will be integrated into the grid on 1st July 2021, at a time when grid demand would be 192322 MW. However, the day of lowest MTL (25.73%) is found to be 27th July 2021, when 108082 MW of solar & wind generation will be integrated into the grid at 1200 hrs. and the grid demand would be 181151 MW during the integration. This integration during offpeak hours (12:00 hrs) would cause thermal generation to back down to 79207 MW with a maximum ramp down rate of 310 MW/min


Interestingly the prediction made for 2021 has come out to be true. It is important to understand the context in which this occurred with covid 19 impacting severely the demand. 
The reality as of July 2021  

  • The max demand as of 6 July is 192 GW( widely tweeted, in fact, peak load touched 200 GW )
  • Renewables in operation 95.6 GW (CEA - nodal agency -monthly report end May 2021 )
  • The Renewables installation is very near 175 GW ( The Hindu business  line article )

Why am I sharing this information about the Indian power system here?

1. Indian electric power system has seen the exit of large multinationals. They have obvious concerns due to ESG.

2. The State players and private sector continue to hold existing thermal assets but have shelved plans to invest further as debt is no longer available.

3. The thermal assets are facing operation and maintenance issues which by and large the staff are not trained to operate.

4. There is clearly a flight of talent to renewables 

5. India needs to significantly raise the standards in Health and Safety and enforce the ESG requirements. This needs a huge management bandwidth in the private sector and State companies which they are yet to develop.

6. Under these conditions it appears that as the leading companies offer to exit the thermal assets, it is not clear who the new owners are likely to be except the distressed asset buyers. It is very likely that this can lead to a serious risk to the safety of these assets in India.

I am interested in suggestions as to how to manage this transition safely in India with actual examples of thermal generating assets undergoing this transition.  

Sankaran Subramaniam's picture
Thank Sankaran for the Post!
Energy Central contributors share their experience and insights for the benefit of other Members (like you). Please show them your appreciation by leaving a comment, 'liking' this post, or following this Member.
More posts from this member
Spell checking: Press the CTRL or COMMAND key then click on the underlined misspelled word.
Jim Stack's picture
Jim Stack on Jul 21, 2021

India is doing very good with renewable power. Do you have any hydro electric sources? They run 24 /7 and can reduce the need for inefficient thermal power plants. Battery storage withe the new long lasting advanced batteries can also be much more efficient that thermal power plants. 

   Also what are the biggest power users after the Sun sets ? Maybe some of that load can be shifted. Look at the complete system and better answers will appear. 

Sankaran Subramaniam's picture
Sankaran Subramaniam on Jul 22, 2021

Jim, Thanks for the response.

Yes, India ( hydro 46GW. 

Battery storage is yet to go in a big way here, we have one 10 MW installed by US company AES corp.

Can you tell me more about long-lasting advanced batteries?

I agree, we need to understand the profile better. Domestic consumption dominates with a large population and mass electrification. Industrial consumers are the first to adapt to Time of day tariffs as they subsidize domestic consumption. India  provides agriculture some form of concessional tariff although lately,  the agricultural load is met by renewables by shifting the demand. 

Hope I have answered. Thanks again for contributing to enhancing our understanding

Jim Stack's picture
Jim Stack on Jul 23, 2021

the new advanced batteries are like the lithium Tesla Mega Packs. They are non toxic and have a 10 year warranty. Treated right they should last twice that long. They keep lowering the costs and increasing the life of these great batteries. 


Sankaran Subramaniam's picture
Sankaran Subramaniam on Jul 23, 2021

That was so useful Jim, thanks a lot


Julian Silk's picture
Julian Silk on Jul 26, 2021

Dear Sankaran,

Thank you for the post.  This isn't the best possible answer, but the GE people and the Polish companies involved in the shut down plant described below may be available, and could possibly provide some insight on how to increase flexibility.  If CCUS technology can be added, which should be possible, it could reduce the rate of emissions growth.


Sankaran Subramaniam's picture
Sankaran Subramaniam on Jul 27, 2021

Thanks a lot Julian Silk for the reference. 

Get Published - Build a Following

The Energy Central Power Industry Network is based on one core idea - power industry professionals helping each other and advancing the industry by sharing and learning from each other.

If you have an experience or insight to share or have learned something from a conference or seminar, your peers and colleagues on Energy Central want to hear about it. It's also easy to share a link to an article you've liked or an industry resource that you think would be helpful.

                 Learn more about posting on Energy Central »