Inter-regional Transfer Capacity

Indian power network is demarcated into five regions (North, East, West, South and North-East) and any power flow from one region to another is restricted by the inter-regional corridor transfer capacity. The graphs below provide information related to transfer capability and transmission reliability margin for different inter-regional corridors.

Inter-regional Transfer Capacity

Intra-regional Transfer Capacity

Indian power network is demarcated into five regions (North, East, West, South and North-East) and there is power flow from one state to another state within each region, with limitation in terms of transfer capacity within a region. The graph below shows the transfer capacity for intra-regional corridors and at the state level, published by POSOCO.

POSOCO Report to APTEL on RE curtailment
APTEL Judgement on RE curtailment
Congestion-warning-notice-on-SR-import-17.11.2018 
Congestion Warning Notice WR-NR & NR Import 22.06.2018 
ATC_NLDC_February’19_Rev8 
ATC_NLDC_April’18_Rev17 
ATC_NLDC_Sep'19_Rev12 
Congestion Warning Notice WR-NR & NR Import 23.06.2018 
CONGESTION-WARNING-NOTICE-25.03.2019 
ATC_NLDC_August’20_Rev13 
ATC_NLDC_May’18_Rev23 
ATC_NLDC_June’18_Rev23 
ATC_NLDC_June'19_Rev24 
ATC_NLDC_Aug'19_Rev10 
ATC_NLDC_Oct'19_Rev4 
ATC_NLDC_Mar'21_Rev42 
ATC_NLDC_Mar16_Rev9 
ATC_NLDC_Nov'19_Rev8 
ATC_NLDC_Dec'19_Rev15 
ATC_NLDC_Jan'20_Rev15 
ATC_NLDC_Feb'20_Rev16 
ATC_NLDC_Mar'20_Rev11 
ATC_NLDC_Apr'20_Rev11 
ATC_NLDC_June'20_Rev28 
ATC_NLDC_May'20_Rev9 
ATC_NLDC_Mar'21_Rev42 
ATC_NLDC_Feb'21_Rev31 
ATC_NLDC_July'19_Rev9 
Congestion-Warning-for-NR-Import-on-Date-15.08.2018. 
Congestion-warning-for-SR-Import-date-16.10.2018. 
CONGESTION-WARNING-NOTICE-31032019_1647hrs 
Import of Maharashtra_Mar'21_Rev0 
(S2&S3)_TTC_ATC_Mar'21_Rev1_19.03.2021_Rev0 
(S2&S3)_TTC_ATC_Mar'21_Rev1_19.03.2021 
Import of Punjab_ATC_Mar'21_Rev0 
ATC_NLDC_July'20_Rev22 
ATC_NLDC_Apr15_Rev23 
ATC_NLDC_June15_Rev13 
ATC_NLDC_May15_Rev35 
ATC_NLDC_July15_Rev13 

Congestion

The Indian power network is demarcated into five regions (North, East, West, South and North-East). The power flow within a region and across regions is limited by the transfer capacity. At certain times, there is a possibility that the demand for power flow is more than the transfer capacity, resulting in congestion within the transmission system. For smoother functioning and grid management, POSOCO provides real-time import-export transmission flows for each region and corridor here
In addition to this, POSOCO also issues congestion warning notices at different time and can be accessed here.

Congestion-warning-notice-on-SR-import-17.11.2018 
Congestion Warning Notice WR-NR & NR Import 22.06.2018 
Congestion Warning Notice WR-NR & NR Import 23.06.2018 
CONGESTION-WARNING-NOTICE-25.03.2019 
Congestion-Warning-for-NR-Import-on-Date-15.08.2018. 
Congestion-warning-for-SR-Import-date-16.10.2018. 
CONGESTION-WARNING-NOTICE-31032019_1647hrs 
ATC_NLDC_Apr'17_Rev19 
Congestion-Warning-for-NR-Import-on-Date-17.08.2018 

Curtailment

The Indian Electricity Grid Code (IEGC) provides must run status to solar and wind power projects. Their curtailment is only allowed to ensure grid security, for example in situations of transmission constraints.

A petition was filed before APTEL regarding the backing down instructions given by SLDC to solar generators in the state of Tamil Nadu. During this process, APTEL directed POSOCO to conduct a third-party assessment on the issue raised by the appellant. The summary on APTEL order and POSOCO report in this regard can be found here.

POSOCO Report to APTEL on RE curtailment
APTEL Judgement on RE curtailment

State Transmission Performance

While there are various parameters against which the performance of a transmission network in a state can be assessed, we have covered two important parameters which are Transmission line losses and Transmission network availability. The graph below shows the performance for 11 states with these two parameters.

State Transmission Performance

GNA allocation by CTU

Central Transmission Utility (CTU) has allocated GNA to state licensees based on the provisions of GNA Regulations, 2022. The graph below presents the GNA allocated to each licensee and compares the same with the maximum demand for the state in 2021-22.

The summary and relevant documents of GNA regulations can be accessed here.

POSOCO Report to APTEL on RE curtailment
APTEL Judgement on RE curtailment
Congestion-warning-notice-on-SR-import-17.11.2018 
Congestion Warning Notice WR-NR & NR Import 22.06.2018 
ATC_NLDC_February’19_Rev8 
ATC_NLDC_April’18_Rev17 
ATC_NLDC_Sep'19_Rev12 
Congestion Warning Notice WR-NR & NR Import 23.06.2018 
CONGESTION-WARNING-NOTICE-25.03.2019 
ATC_NLDC_August’20_Rev13 
ATC_NLDC_May’18_Rev23 
ATC_NLDC_June’18_Rev23 
ATC_NLDC_June'19_Rev24 
ATC_NLDC_Aug'19_Rev10 
ATC_NLDC_Oct'19_Rev4 
ATC_NLDC_Mar'21_Rev42 
ATC_NLDC_Mar16_Rev9 
ATC_NLDC_Nov'19_Rev8 
ATC_NLDC_Dec'19_Rev15 
ATC_NLDC_Jan'20_Rev15 
ATC_NLDC_Feb'20_Rev16 
ATC_NLDC_Mar'20_Rev11 
ATC_NLDC_Apr'20_Rev11 
ATC_NLDC_June'20_Rev28 
ATC_NLDC_May'20_Rev9 
ATC_NLDC_Mar'21_Rev42 
ATC_NLDC_Feb'21_Rev31 
ATC_NLDC_July'19_Rev9 
Congestion-Warning-for-NR-Import-on-Date-15.08.2018. 
Congestion-warning-for-SR-Import-date-16.10.2018. 
CONGESTION-WARNING-NOTICE-31032019_1647hrs 
Import of Maharashtra_Mar'21_Rev0 
(S2&S3)_TTC_ATC_Mar'21_Rev1_19.03.2021_Rev0 
(S2&S3)_TTC_ATC_Mar'21_Rev1_19.03.2021 
Import of Punjab_ATC_Mar'21_Rev0 
ATC_NLDC_July'20_Rev22 
ATC_NLDC_Apr15_Rev23 
ATC_NLDC_June15_Rev13 
ATC_NLDC_May15_Rev35 
ATC_NLDC_July15_Rev13