Gridlock On The Green Path: Transmission Delays Trigger Massive Power Waste
India’s green energy boom faces a costly hurdle as lagging power lines and grid congestion force massive wastage, sparking a push for battery storage.
India may be trying to achieve ambitious renewable energy targets, but the infrastructure to carry that power is still struggling to keep pace. After a decade where Rajasthan and Gujarat emerged as the nation's solar powerhouses, the industry is now grappling with the technical reality of curtailment, or the forced idling of power plants.
In the renewable energy sector, curtailment refers to the deliberate reduction in output from power plants, either to maintain grid stability or because the transmission lines are simply fewer to carry the volume of electricity being generated.
The Infrastructure Gap
Industry associations report that the average curtailment across major renewable energy (RE) states such as Rajasthan, Gujarat, and Karnataka has hovered between 15 and 20% over the last year. In some cases, mid-day peak-hour curtailment reached 100% until January 2026.
The crisis is primarily driven by corridor congestion. While India has surpassed 200 GW of RE capacity (excluding Hydro power), with Rajasthan and Gujarat accounting for more than 40 GW each, the physical transmission lines needed to evacuate this power remain stuck in development.
Why The Lines Are Lagging
India’s green energy additions have been galloping. A recent SBI Caps report on the power sector highlighted that 40 GW of solar capacity is estimated for addition in 2025. However, transmission infrastructure additions lagged nearly 50% behind their targets as of late FY26.
Transmission infrastructure addition has been slow because of a plethora of issues — right of way, land acquisition, equipment shortage and idle transmission capacity reserved for stranded plants.
“While the ISTS ((Inter-State Transmission System) waiver for RE projects accelerated RE deployment, it in turn reduced the spatial diversity of projects, with most concentrated in Gujarat and Rajasthan, leading in turn to transmission bottlenecks and associated problems,” Ashwin Gambhir, a fellow at Prayas, a Pune-based non-profit research group that focuses on energy, said. Gujarat and Rajasthan are preferred because of their advantage of being sunny states.
Gambhir from Prayas notes curtailment of some amount of RE power is a “well-known feature of systems with a high share of variable renewables as evidenced in many countries.”
Despite the local friction, experts argue that some degree of power wastage is an unavoidable part of a modern green energy system. Ashwin Gambhir pointed out that unplanned shutdowns or essentially last-minute requests to stop generating power to keep the grid stable accounted for only 3.7% of India's total wind and solar generation in the second half of 2025.
To put that into perspective, roughly 2 billion units (TWh) of electricity were held back during those six months, as Emergency Tertiary Reserve Ancillary Service (TRAS) Down curtailment . While the rate of wasted power hit a high of 10% in October, it dropped to almost nothing by January 2026 as daytime demand for electricity across the country increased. These short-notice pauses are a standard safety measure used worldwide. When there is suddenly more power being produced than the country is using, grid operators ask plants to dial back to prevent equipment damage.
In these specific cases, the power producers are usually compensated for the loss. India’s current levels of wastage are considered typical, matching what is seen in other developed nations that rely heavily on sun and wind.
Economic Causalities
The inability to move power is not just a technical glitch; it is an economic drain. Ravi Verma, a member of the Governing Council of the Sustainable Projects Developers Association (SPDA), estimates that ongoing congestion erodes approximately Rs 0.25 to Rs 0.30 per kWh from project tariffs.
“For large RE zones in Rajasthan, evacuation delays of 15–24 months have materially impacted project cash flows, significantly affecting developer returns and bankability,” he said.
S&P Global Energy warned in January that after years of rapid growth, these widespread restrictions are beginning to limit future solar expansion.
Publicly traded solar energy firms are now reporting these losses to shareholders. Acme Solar recently disclosed a one-time loss of approximately Rs 17.5 crore at its 300 MW Sikar project due to restricted grid access.
In some cases, depending on how the lapse occurred, the government may compensate for it.
Time For Batteries To Shine
While augmenting transmission infrastructure is a multi-year effort, almost every stakeholder in the power sector is hopeful that energy storage systems will help store what the grid cannot evacuate at a particular hour.
Major players like Adani Green Energy have signalled an aggressive push into battery storage for the coming financial year. These batteries act as a shock absorber, soaking up excess power during peak sun hours that the grid cannot currently handle, and discharging it when demand rises or congestion clears.
“So in a nutshell, this battery storage will act as absorbing the power, which otherwise would have been curtailed on a short-term basis,” the executive said.
The Road Ahead
There are already signs of a reprieve. S&P expects the risk of forced shutdowns to fall below 0.5% in 2026, though they attribute this partly to a "cautious investment environment" and slower solar growth alongside a 6% rise in power demand.
A slew of companies, such as Adani Green, NTPC, Acme Solar, and others, have indicated they expect things to improve in the coming months, with minor or zero curtailments, as new transmission capacities get added. Acme, for instance, noted with effect from December 14, 2025, ACME Sikar, its subsidiary, is operating at full capacity without any curtailment.
Verma from SPDA notes that while incremental transmission capacity has been added, the speed lag continues to haunt. “The improvement has been limited and insufficient to offset the scale and speed of new RE commissioning. The core issue remains asynchronous planning and delays in execution faced in execution of transmission lines, wherein renewable generation is commissioned in 12–24 months, whereas ISTS transmission takes three to five years.”
He warned that if such curtailments continue, it poses serious systemic risks, including curtailment becoming a leading indicator of future power shortages, rather than surplus.
Gambhir has a word of advice: “While we certainly need to plan for much higher system flexibility to minimise curtailment, we should also accept that some amount of curtailment of very low-cost renewables is still the most cost-optimal option.”
SPDA’s Verma notes the issue has received ‘policy-level’ recognition; however, structural solutions such as corridor-wise prioritisation, transmission-first sequencing, early warning mechanisms, and accountability frameworks are yet to be institutionalised.
In addition, faster addition of new transmission capacities along with timely execution of battery storage projects would be key developments to watch out for.
