Solar Park Developer Asked Not to Stop Generators from Feeding Excess Energy to the Grid

The Rajasthan Electricity Regulatory Commission (RERC) directed a solar park developer in the state to not obstruct solar power generators from evacuating the generated solar power up to 110% of the project’s rated capacity. The Commission said that if the power injection created grid disturbance, then the state load dispatch center (SLDC) or the distribution companies (DISCOMs) were free to issue directions to the solar developers.


ACME Jodhpur Solar Power Private Limited and ACME Rewa Solar Power Private Limited had filed a petition seeking directions from the Commission to stop Saurya Urja Company of Rajasthan Limited from obstructing generation and evacuation of solar energy.

Saurya Urja is a joint venture company between the Government of Rajasthan and IL&FS, incorporated to plan, develop, and operate solar parks in Rajasthan.  Earlier, ACME had signed a power purchase agreement (PPA) with the Solar Energy Corporation of India (SECI) to sell the generated power. The two ACME projects with a capacity of 100 MW each were commissioned on September 21, 2018, and September 24, 2018.

The petitioners (subsidiaries of ACME) operate their solar power projects at the Bhadla Solar Park and are connected to the 220/400 kV substation of Saurya Urja Company. Other than the solar power generators, SB Energy having a capacity of 300 MW, is also connected to the substation. So, a total of 500 MW is connected to the Saurya Urja substation, which has a capacity of 625 MVA.

In their submission, the solar generators said that the substation’s capacity to which projects are connected is 625 MVA (125*5 MVA). This means that there is an additional margin of 125 MW. Therefore, the solar park developer developed the evacuation infrastructure capable of evacuating more than 20% of the contracted capacity of 100 MW each during peak hours.

The petitioners added that neither SECI, the SLDC nor the DISCOMs objected to such occasional over injection of power during short spells of peak hours.

The solar generators said that restricting solar generation was a waste of natural resources and was against the Indian Electricity Grid Code (IEGC) and RERC regulations, which accorded the ‘must-run’ status to solar and wind power projects.

Saurya Urja, in its reply, said that the over-injection of power was endangering the safety of the equipment installed, apart from there being issues of grid security. Therefore, ‘must-run’ status cannot be viewed in isolation and has to be considered from the point of the stability of the infrastructure and the equipment installed and for securing the safety of the same and the grid’s stability.

Even if the deviation settlement mechanism (DSM) regulations allow deviation from the schedule by 15% without any penalty, it would not automatically mean that the solar generators could over-generate where the peak of the capacity reached is higher than the rated capacity.  The solar park developer stated that the solar generators could install a battery storage system to absorb the excess generation in peak hours and supply it to the grid when the solar radiation level reduces.

Commission’s Analysis

The Commission said that the solar park developer was arbitrarily, unreasonably, and without any authority restricting the over injection of power to the grid.

It further noted that the infrastructure developed by Saurya Urja is not an interstate transmission system (ISTS); but an intrastate transmission system and is within the jurisdiction of the Commission.

“It is observed that the evacuation infrastructure developed by Saurya Urja to which petitioners are connected has a capacity of 625 MVA whereas a total of 500 MW load is connected to sub-station developed by Saurya Urja. Thus, there is an additional margin of 125 MW. Further, transmission elements have an additional 10% margin of the rated capacity,” the Commission added.

The Commission said that the DISCOMs could instruct the solar generator to reduce the generation if such an injection of additional power causes disturbance in the system. The Commission noted that the solar power generators should not be restricted to occasionally inject power over the rated capacity until it creates grid disturbance.

Discussing the order, Aditya K Singh, Associate Partner, HSA Advocates, said, “We must be grateful to the RERC, which is taking the courage to provide an out-of-the-box solution to the problems being faced by developers. Unlike most other Commissions, it is not wasting its time in finding a precedent. It is taking the effort to understand the problem and provide the solution. In the instant case, solar developers were being restricted by the solar park developer to inject solar power in the grid allegedly beyond the contracted capacity. RERC held that injection could only be restricted on the ground of grid security. Commission not only referred to contractual and legal provisions to adjudicate but also relied on the existing capacity of the solar park to provide relief to the developer.”

The Commission directed Saurya Urja Company not to obstruct generators from evacuating solar power up to 110% of the project’s rated capacity. But, if the power injection creates grid disturbance, the SLDC or DISCOM could issue any direction to generators as per Act and Regulations.

“The Commissions should realize that there is a purpose behind the creation of a specialized body of the adjudication, giving freedom from clutches of the procedural law, and appointment of adjudicators having knowledge of the law, engineering, finance, commerce, economics, and management. This order has also affirmed that generators can approach the Commission against the solar park developer (even if it is not a regulated entity under the Electricity Act),” he added.

In January this year, a panel reviewing the Indian Electricity Grid Code 2020 suggested that wind, solar, wind-solar hybrid, and hydro projects must be treated as ‘must-run’ power projects. The draft report also indicated that these projects should not be subjected to curtailment based on merit order dispatch or any other commercial consideration.

Recently, Mercom discussed in an article how renewable curtailment still continues to be a major issue for generators in several states.

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