ISTE Connected Solar-Wind Hybrid, Renewable energy (RE) ,BESS Project | ISTS Solar Projects | ISTS Charges | ISTS Losses

Inter-State Transmission System (ISTS) #Central Electricity Regulatory Commission (CERC)

What is ISTS ?

Any system for the conveyance of electricity by means of a main transmission line from the territory of one State to another State is called ISTS (definition is given by POSOCO)

What is ISTS based solar project ?

In ISTS-based Solar project, power generated from one state can be transmitted to other states. ISTS, the developers can bid for their choice of project and location anywhere in India. After getting Developers setting up a solar power plant (or park) at the place allocated to them and build electricity transmission lines to the nearest grid network. The voltage at PV inverter’s output point is low, which needs to be stepped up through a pooling substation. And the development of the same is also in developer’s scope. Customers of developers, can purchase power through gird transmission lines.

Most of the PV energy generators did not have to worry about transmission costs or the cost of scheduling.

• Wind or early solar projects, selling power under feed-in tariff (FIT) to distribution companies (DISCOMs), need only to connect to the grid. Additional transmission costs are not charged from either the generators or the consumers.
• Open-access consumers buying power using the state grid pay transmission and wheeling charges in INR/ kWh and may see direct benefit of transmission capacity optimization.
• Most states offer banking facility, and the banked power can be used up to a year. Generator does not need to optimize generation schedule to match demand with supply

As per data available on the site of Power System Operation Corporation Limited, inter-state transmission of energy is chargeable (but what about solar? keep reading), and this consist two type of charges transmission charges or ISTS charges and ISTS losses.

The method of computing charges is called Point of Connection (PoC) Charging Method. And the same is developed by POSOCO (Power System Operation Corporation Limited) in compliance of Central Electricity Regulatory Commission.

“Point of connection Charging Method shall mean the methodology of computation of sharing of ISTS charges and losses amongst Designated ISTS Customers, which depends on the location of the node in the grid and is calculated in accordance with Regulation “

What are the ISTS charges and losses for Solar projects?

As per the Central Electricity Regulatory Commission notification on 06.11.2019,

"No transmission charges and losses for the use of ISTS network shall be payable for the generation based on solar and wind power resources for a period of 25 years from the date of commercial operation of such generation projects if they fulfill the following

conditions:

1. Such generation capacity has been awarded through competitive bidding;
2. Such generation capacity has been declared under commercial operation;
3. Power Purchase Agreement(s) have been executed for sale of such generation capacity to all entities including Distribution Companies, for compliance of their renewable purchase obligations

Further more about ISTS charges and losses (not for solar and wind power)

Now here are some terminologies used by POSOCO

Developers = Injecting DIC (or Injecting Designated ISTS Customers).

And Developer’s customers = Drawee DIC (or Drawee Designated ISTS Customers).

ISTS Charges

ISTS tariff is determined as per the CERC (Terms and Conditions of Tariff), Regulations, 2009. ISTS licensee submits tariff petition for approval by CERC.

ISTS Losses

The procedure for sharing of Inter-State transmission system losses is developed by POSOCO (Power System Operation Corporation Limited) in compliance of Central Electricity Regulatory Commission.

Let the Injecting DIC is located in Region-1 and the power is wheeled through Region-2 and the Drawee DIC is located in Region-3.

Also let the contracted quantum power be P.

Let Effective PoC Loss percentage of the injecting DIC in Region-1 be ‘a’ and that of drawee DIC in Region-3 be ‘b’ then the Injecting DIC has to inject P/(1-a/100)

The schedule at the inter-regional boundary between Region-1 and Region-2 shall be P and that between Region-2 and Region-3 shall also be P.

The schedule of drawee DIC shall be = P*(1-b/100).

For the easy of your understanding about ISTS losses.

Waving off ISTS charges and losses on ISTS solar projects, will helpful for all Solar industrialist or it will be beneficial to Big players only? Leave a comment below.

Offshore Wind Projects Starting Before 2033 To Get 25 Years Of ISTS Waiver In India

The extended waiver for offshore wind projects, besides green Hydrogen and ammonia is in line with ammonia is in line with expectations that these projects will actually start post 2025.

ISTS waiver of Green Hydrogen and Green Ammonia projects extended from 30 June 2025 to 31 Dec 2030.

In a big boost to off-shore wind energy projects, Government gives complete waiver of ISTS charges for 25 years to projects commissioned on or before 31st Dec, 2032

In a major decision, the Government has decided to grant waiver of ISTS charges to Off-Shore Wind Projects and extend the waiver to Green Hydrogen/Green Ammonia . This decision has been taken to facilitate wider execution of offshore wind energy initiatives, to promote the expansion of Green Hydrogen / Green Ammonia Projects and to encourage the offtake of renewable energy from Energy Storage System Projects.

As per the notification issued by Ministry of Power, a complete waiver of ISTS charges (Inter-State Transmission Charges) has been given for off-shore wind power projects commissioned on or before 31st?December, 2032 for a period of 25 years from the date of commissioning of the Project. The off-shore projects commissioned from 1st?January, 2033 would be given graded ISTS charges. Earlier, all wind energy projects were provided waiver upto 30.06.2025. Now, offshore wind would be treated separately, and waiver to these would granted up to 31st?Dec, 2032 with graded transmission charges thereafter.

To promote development of Pump Storage Plants (PSP), the criteria for availing the complete waiver of ISTS charges for PSP projects has now been linked to the date of award of the project rather than commissioning of the project. This shall be applicable in cases where construction work is awarded on or before 30th?June, 2025.

The ISTS charges on drawl of energy from energy storage projects, which was earlier granted to the project, will henceforth be available for each individual user of such project. The individual user will get this benefit, if at least 51% of the energy utilized by the user for charging the storage system is renewable energy. Earlier the limit of 51% was at project level. This change has been proposed in view of the fact that in future the capacity of such storage projects will be shared by many discoms / other users and only some of them may meet this criteria of 51% individually while the same may not be met in an aggregate manner at storage project level.

Moreover, in case a project is eligible for waiver of transmission charges based on its original COD (Date of Commissioning), the same benefit will continue to be made available if COD is extended by competent authority. This is considered necessary to give confidence to the investors who are taking investment decisions based on the present circumstances but their COD may extend beyond the relevant applicable date for transmission charge waiver for reasons beyond their control.