Between April and June 2026, India curtailed approximately 8,133 GWh of solar electricity because transmission bottlenecks and grid-security requirements prevented the power system from absorbing the full available output.

Curtailment reached approximately 2,417 GWh in April, 3,235 GWh in May and 2,481 GWh in June. The total recorded in only three months exceeded the roughly 6,900 GWh curtailed during the whole of the previous financial year.

This is not evidence that India has built too much solar power. It is evidence that renewable generation and grid infrastructure are not always being completed at the same speed.

India’s Solar Growth Has Entered a New Stage

By mid-2026, India had approximately 162.15 GW of installed solar capacity across utility-scale projects, rooftop systems, hybrid installations and off-grid applications.

For years, the main objective was straightforward: install more renewable capacity. That strategy has delivered significant results, but the next stage is more complex.

Solar electricity must still be collected, transmitted, balanced and delivered. When the supporting network is incomplete, a power plant may be ready to generate while the grid remains unable to accept its full output.

India’s renewable expansion is increasing pressure on transmission and evacuation infrastructure.

Why Is Solar Power Being Curtailed?

Solar curtailment occurs when a plant is technically capable of generating electricity but is required to reduce its output.

The most common causes include:

India’s government has identified a mismatch between the commissioning of renewable projects and the transmission systems designed to carry their electricity.

Solar farms can often be constructed relatively quickly. Transmission projects usually require more time for route planning, land acquisition, utility coordination, approvals, equipment procurement and commissioning.

When the solar plant finishes first, electricity may be available without a complete route to the market.

Curtailment Is Also a Financial Risk

For developers, installed capacity does not automatically equal project revenue.

A solar plant earns money from the electricity it successfully exports. If the grid repeatedly limits output, the project may deliver less energy than expected even when its modules and inverters are operating normally.

Site selection can therefore no longer depend only on irradiation, land availability and construction cost. Developers also need to review available transmission capacity, regional curtailment history, substation access and the expected completion date of grid infrastructure.

The Missing Link Is the Entire Evacuation Chain

It is tempting to describe India’s solar curtailment simply as a shortage of transmission lines. However, a transmission line cannot operate in isolation.

A delay or capacity shortage at any point can restrict the whole project. The evacuation substation must accept power from the plant, the transmission network must carry it, and receiving substations must transfer it into regional or distribution networks.

Energy storage and improved forecasting can increase flexibility, but they do not eliminate the need for physical grid infrastructure.

transformers enter the discussion here—not as a standalone solution to curtailment, but as part of the substations that connect different voltage levels throughout the power system. If a transmission corridor is completed while its substation, switchgear or transformation capacity remains unfinished, a renewable project may still be unable to export at full output.

A renewable project depends on the readiness of the complete evacuation and grid-connection system.

What Should Developers and EPC Contractors Check Earlier?

India’s experience suggests that grid readiness should be assessed before the main generation equipment is fully committed.

transformers, switchgear and protection systems should be specified according to the approved connection design and planned energisation date. Ordering too late can create another bottleneck, while ordering before utility parameters are confirmed can result in redesign and approval delays.

A Wider Lesson for Emerging Renewable Markets

India is not alone. Countries across Southeast Asia, West Asia, Africa and South America are also adding solar generation faster than some sections of their transmission and distribution networks are being upgraded.

The same pattern can occur wherever:

• Renewable resources are located far from major demand centres
• Grid investment has historically lagged generation investment
• Existing substations have limited spare capacity
• Equipment and grid-connection schedules are poorly coordinated
• Electricity demand changes sharply throughout the day

For these markets, the next phase of renewable growth will depend less on how many solar panels can be installed and more on the readiness of the network surrounding them.