India’s Solar Energy Transition

India has successfully achieved its Nationally Determined Contribution (NDC) target of sourcing 50% of its installed electricity capacity from non-fossil fuel sources well before the 2030 deadline. This achievement reflects the country's rapid progress in renewable energy deployment. However, recent developments such as the curtailment of 2.3 TWh of solar power and the existence of 44 GW of awarded capacity without signed Power Purchase Agreements (PPAs) indicate that India’s renewable energy transition is no longer primarily a capacity challenge. Instead, it has become a system-level challenge involving transmission infrastructure, grid management, storage, and financial sustainability.

India’s Current Solar Energy Status

India has emerged as one of the world's leading renewable energy producers. According to the International Renewable Energy Agency (IRENA) 2025, India ranks third globally in solar energy capacity and fourth in overall renewable energy capacity.

In 2025 alone, the country added a record 38 GW of solar capacity, taking the total installed solar capacity to approximately 136 GW. India has already surpassed its interim renewable energy milestones and remains on track to achieve its target of 500 GW of non-fossil fuel capacity by 2030.

Looking further ahead, NITI Aayog projects that India's solar capacity could reach 1,500 GW by 2050 under existing policy frameworks and potentially 2,400 GW under a Net-Zero pathway.

While solar generation capacity has expanded rapidly, the supporting infrastructure and governance mechanisms have not kept pace. As a result, the focus is shifting from adding generation capacity to ensuring efficient integration of renewable energy into the power system.

The Core Challenge: A Grid Not Designed for Large-Scale Solar Integration

The most significant issue facing India's solar sector today is the mismatch between generation growth and grid readiness.

Between May and December 2025, India curtailed approximately 2.3 TWh of solar electricity, forcing compensation payments ranging from ₹575 crore to ₹690 crore to solar generators. This lost generation could have displaced coal-based power and prevented nearly 2.1 million tonnes of carbon dioxide emissions.

States such as Rajasthan, Gujarat, and Tamil Nadu, which host large solar installations, experienced solar curtailment levels ranging between 10% and 30% during peak sunlight hours. The primary reason was the inability of transmission infrastructure to evacuate and transport power to consumption centres.

This highlights a fundamental reality: India's electricity grid was originally designed around conventional thermal power plants and is struggling to accommodate rapidly expanding renewable energy sources.

Unsigned PPAs: A Major Investment Bottleneck

One of the most serious obstacles facing the sector is the growing backlog of unsigned Power Purchase Agreements (PPAs).

As of September 2025, approximately 44 GW of awarded renewable energy capacity remained stranded because PPAs had not been signed. This situation has emerged due to several factors, including:

• Financial concerns of DISCOMs.

• Changing preferences among power purchasers.

• Delays in transmission infrastructure development.

Without a signed PPA, developers cannot achieve financial closure, secure loans, or begin project construction. Consequently, significant investment remains frozen despite projects being awarded.

This issue represents a major governance challenge rather than a technological limitation.

Transmission Infrastructure Lagging Behind

India's solar resources are concentrated in states such as Rajasthan and Gujarat, while major electricity demand centres are located in Delhi, Maharashtra, West Bengal, and southern metropolitan regions.

The transmission network required to transport renewable power across long distances has not expanded at the same pace as generation capacity.

As a result, even when solar power is available, inadequate transmission corridors often prevent its delivery to consumers, leading to curtailment and underutilisation of renewable assets.

The problem demonstrates that renewable energy growth requires simultaneous investment in both generation and transmission infrastructure.

Financial Stress in DISCOMs

The financial health of Distribution Companies (DISCOMs) continues to be a major concern.

Aggregate Technical and Commercial (AT&C) losses remain around 16%, while tariff under-recovery persists across several states.

Financially weak DISCOMs often:

• Delay signing PPAs.

• Avoid long-term procurement commitments.

• Postpone payments to power generators.

This creates uncertainty for investors and discourages fresh investment in both renewable generation and grid infrastructure.

Unless DISCOM finances improve, the renewable energy transition will continue to face structural obstacles.

Coal Fleet Rigidity and Limited Solar Absorption

Despite rapid renewable growth, coal still contributes nearly 75% of India's electricity generation.

Most coal power plants operate with a Minimum Technical Load (MTL) of around 55%, meaning they cannot easily reduce generation below this threshold.

As solar generation peaks during midday, coal plants continue producing significant power, limiting the available space for solar energy within the grid.

Without improving coal plant flexibility or expanding storage infrastructure, solar curtailment is likely to increase as renewable capacity grows further.

Supply Chain Constraints

The renewable energy sector is also facing supply-chain bottlenecks.

Lead times for critical transmission equipment, particularly 220 kV and 400 kV transformers, increased to nearly 20 months in 2025.

Such delays directly affect transmission projects and slow the evacuation of power from renewable energy parks.

Therefore, strengthening domestic manufacturing capabilities for grid infrastructure has become increasingly important.

Challenges in Rooftop Solar Expansion

India's rooftop solar programme, especially under PM Surya Ghar, has not achieved expected momentum.

Several operational issues have emerged, including:

• Shortages of Domestic Content Requirement (DCR) compliant solar modules.

• Duplicate serial number errors on online portals.

• State-level restrictions on net metering.

These challenges have slowed the expansion of decentralised solar generation despite strong consumer interest.

Government Initiatives Supporting Renewable Integration

Recognising these challenges, the government has launched several initiatives.

Green Energy Corridor Programme

The Green Energy Corridor (GEC) Phase I and II projects aim to build dedicated transmission infrastructure for renewable energy integration and are expected to facilitate evacuation of approximately 20 GW of renewable capacity.

National Smart Grid Mission

The National Smart Grid Mission seeks to modernise electricity distribution through:

• Smart meters.

• Grid automation.

• Demand response systems.

These measures enhance grid flexibility and improve renewable integration.

Revamped Distribution Sector Scheme (RDSS)

The RDSS focuses on reducing AT&C losses, strengthening distribution infrastructure, and improving DISCOM performance through outcome-based financial support.

PM-KUSUM Scheme

The PM-KUSUM programme promotes decentralised solar power generation in the agricultural sector, reducing pressure on both DISCOMs and transmission networks.

Production Linked Incentive (PLI) Scheme

The PLI Scheme for Solar PV Manufacturing encourages domestic production of solar cells and modules, reducing import dependence and enhancing energy security.

Similarly, the Battery Energy Storage PLI Scheme aims to support domestic manufacturing of storage technologies necessary for renewable integration.

Way Forward

Enhancing Coal Plant Flexibility

India must reduce the Minimum Technical Load (MTL) of coal power plants below the current 55% threshold through technical upgrades and operational reforms.

This would create greater space for solar generation during daylight hours and reduce curtailment.

Time-Bound PPA Signing

A central regulatory framework under the Central Electricity Regulatory Commission (CERC) should mandate signing of PPAs within 90 days of project allocation.

Such a measure would eliminate the current 44 GW backlog and restore investor confidence.

Expansion of Battery Energy Storage Systems (BESS)

Large-scale deployment of Battery Energy Storage Systems (BESS) in renewable-rich states such as Rajasthan and Gujarat is essential.

India should target at least 10 GW of storage capacity by 2027 to absorb excess solar generation during the day and supply electricity during evening peak demand.

Reforming DISCOM Finances

States with persistently high AT&C losses should adopt professional management reforms, public-private partnership models, or selective privatisation to improve financial viability.

Financially healthy DISCOMs are critical for long-term renewable energy investment.

Transition to Security-Constrained Economic Dispatch (SCED)

India should move from fragmented state-level dispatch systems toward a national Security-Constrained Economic Dispatch (SCED) framework.

This would enable least-cost electricity dispatch across state boundaries and minimise renewable curtailment arising from contractual rather than physical constraints.

Demand-Side Management

Scaling up smart meters to approximately 250 million households by 2028 and introducing Time-of-Day (ToD) tariffs can shift electricity consumption toward periods of high solar generation.

Such measures transform consumers into active participants in grid balancing.

Conclusion

India's solar energy journey has entered a new phase. The challenge is no longer merely installing more renewable capacity but ensuring that generated power can be effectively transmitted, stored, and consumed.

Issues such as solar curtailment, transmission bottlenecks, unsigned PPAs, financially stressed DISCOMs, and inadequate storage infrastructure reveal that the country's renewable transition is fundamentally a systems integration challenge.