1. Introduction

A hybrid renewable system combining wind generation with energy storage is an electricity project in which electricity generated by wind turbines is integrated with a storage system—most commonly a Battery Energy Storage System (BESS), pumped-storage facility, or another Energy Storage System (ESS)—to provide electricity with greater flexibility, reliability and dispatchability.

The legal significance of the model is that the project is no longer simply a conventional wind-generating station. It involves several legally regulated functions:

renewable electricity generation;

energy storage and charging/discharging;

grid connectivity;

forecasting and scheduling;

deviation settlement;

transmission and distribution;

electricity-market participation;

power purchase agreements (PPAs);

tariff determination or competitive bidding;

renewable-energy compliance; and

grid-security obligations.

In India, the regulatory framework has increasingly moved toward treating renewable generation and storage as integrated electricity-system resources. CERC's 2024 Renewable Energy Tariff Regulations expressly recognise “renewable energy with storage projects” and renewable hybrid projects. (CERC)

2. Meaning of a Wind + Storage Hybrid System

A simplified configuration is:

Wind Turbines → Power Conversion System → Common Interconnection Point → Grid

with:

Wind Turbines → Storage System → Inverter → Common Interconnection Point → Grid

The storage system can absorb electricity when wind generation exceeds the desired grid injection and discharge when wind production falls.

For example, a project may contain:

100 MW wind generation;

50 MW / 100 MWh BESS;

a common grid-interconnection point;

an energy-management system;

forecasting and scheduling software; and

a PPA requiring firm or scheduled power delivery.

The legal question is therefore not merely “Is wind energy renewable?” but also:

What is the legal character of electricity when renewable generation and storage operate together?

This question affects tariff, metering, renewable-energy certificates, scheduling, deviation charges, grid access and contractual obligations.

3. Indian Legal Framework

A. Electricity Act, 2003

The Electricity Act, 2003 provides the foundational statutory framework.

Important provisions include:

Section 61 — Tariff principles

Regulatory commissions must frame tariff regulations taking into account principles such as:

consumer interest;

recovery of reasonable costs;

efficient operation;

promotion of renewable energy;

economic use of resources; and

safeguarding of electricity-sector efficiency.

For hybrid wind-storage projects, these principles become relevant when determining how the costs of wind generation and storage should be recovered.

Section 62 — Tariff determination

Where tariff is determined by the appropriate regulatory commission, Section 62 provides the principal statutory route.

A hybrid project may therefore be subject to regulatory tariff determination where the applicable legal framework permits it.

Section 63 — Competitive bidding

Where tariff has been determined through a transparent competitive bidding process conducted in accordance with Central Government guidelines, the appropriate Commission adopts the discovered tariff.

This is particularly important because India's renewable and storage market is increasingly based on competitive procurement rather than traditional project-specific tariff determination.

The Supreme Court has repeatedly emphasised the importance of Section 63 and the contractual terms governing competitively discovered tariffs. (Indian Kanoon)

Section 79

CERC has jurisdiction over matters involving inter-State electricity transactions and other functions assigned to it under the Act.

Consequently, large ISTS-connected wind-storage projects may fall substantially within CERC's regulatory jurisdiction.

4. Recognition of Renewable Energy with Storage

A major development is CERC's Renewable Energy Tariff Regulations, 2024.

These regulations define:

“Renewable energy with storage project”

as a combination of renewable energy projects with storage, or a combination of renewable hybrid energy projects with storage, at the same interconnection point.

They separately recognise a renewable hybrid energy project as a renewable project combining renewable sources at the same interconnection point. (CERC)

This is important because it provides a regulatory basis for treating storage as part of the architecture of a renewable-energy project rather than merely as an unrelated electricity asset.

5. Storage as a Legal Electricity Asset

Historically, electricity regulation was largely based upon three categories:

generation;

transmission; and

distribution.

Storage complicates this traditional classification because a BESS can:

consume electricity while charging;

store electricity; and

inject electricity while discharging.

Therefore, storage can behave partly like a consumer and partly like a generating resource.

This creates important legal questions concerning:

electricity duty;

transmission charges;

open access;

wheeling;

metering;

scheduling;

deviation;

ancillary services;

market participation; and

treatment of renewable attributes.

6. Common Interconnection Point

The common interconnection point is particularly important.

CERC's regulatory framework recognises hybrid projects where generation is integrated at a common point of interconnection. The 2024 framework also addresses renewable hybrid projects through common interconnection and metering arrangements. (CERC)

A common point makes it possible to treat the project as an integrated system for:

scheduling;

metering;

grid injection;

transmission access;

forecasting; and

contractual delivery.

This is particularly valuable where the PPA requires a certain amount of firm power rather than merely variable wind generation.

7. Forecasting and Scheduling

Wind generation is inherently variable.

A wind-only project therefore faces uncertainty between:

forecast → scheduled generation → actual generation

Storage can reduce this mismatch.

For example:

Forecast wind generation = 70 MW

Actual wind generation = 55 MW

Storage discharge = 15 MW

Grid injection = 70 MW

The storage system can therefore help the project comply with its schedule.

CERC's deviation framework specifically recognises situations involving a WS seller with ESS connected at the same interconnection point. It provides different treatment depending on whether electricity is being injected from wind/solar/hybrid generation, injected from the ESS, or drawn by the ESS. (CERC)

This represents a significant development in electricity regulation because the legal framework increasingly recognises the operational distinction between renewable generation and storage.

8. Deviation Settlement Mechanism

Deviation Settlement Mechanism (DSM) rules become especially important for wind-storage projects.

Suppose:

Scheduled injection = 100 MWh

but:

Actual renewable generation = 80 MWh

Without storage, the project has a 20 MWh shortfall.

With storage, it may discharge 20 MWh and achieve:

Wind = 80 MWh + Storage = 20 MWh = Grid injection 100 MWh

This can substantially change the project's deviation exposure.

CERC's framework provides that for a WS seller with ESS at the same interconnection point, deviation charges vary depending on whether the renewable plant is injecting, the ESS alone is injecting, or the ESS is drawing from the grid. It also requires appropriate metering so that generation and ESS charging/discharging can be captured. (CERC)

9. Must-Run Status

Wind power plants have traditionally benefited from the regulatory principle of priority dispatch.

The Electricity (Promotion of Generation of Electricity from Must-Run Power Plant) Rules, 2021 recognise wind and wind-solar hybrid plants as must-run facilities, subject to the technical-security exception.

Courts have considered disputes concerning curtailment of wind generation.

In Ushdev Engitech Ltd. v. TANGEDCO/TANTRANSCO/SLDC, the Madras High Court referred to the regulatory framework under which wind, solar and wind-solar hybrid plants are treated as must-run, while recognising that curtailment may occur for technical constraints or grid-security reasons. (Indian Kanoon)

For wind + storage systems, this raises an important distinction:

Storage may provide flexibility, but it does not automatically eliminate the legal requirements governing renewable generation curtailment.

10. Procurement and Competitive Bidding

India has increasingly moved toward competitive procurement of renewable power.

CERC's current bidding framework includes:

wind procurement;

wind-solar hybrid procurement;

renewable energy plus storage procurement; and

firm and dispatchable renewable power with ESS. (CERC)

For example, the Government's 2023 guidelines provide a framework for procurement of firm and dispatchable power from grid-connected renewable-energy projects with ESS. (CERC)

This is important for wind-storage projects because storage transforms the commercial proposition from:

“We will generate whatever wind power is available”

toward:

“We will provide electricity according to specified delivery obligations.”

The latter resembles a firm-power product.

11. PPA Regulation

A wind-storage PPA should clearly establish:

Generation obligations

installed wind capacity;

storage capacity;

contracted capacity;

minimum energy obligations.

Storage obligations

charging source;

charging restrictions;

discharge obligations;

minimum state of charge;

degradation responsibility;

replacement obligations.

Delivery obligations

scheduled power;

firm-power windows;

ramp rates;

availability;

capacity utilisation.

Risk allocation

change in law;

force majeure;

grid curtailment;

transmission delays;

battery degradation;

equipment failure;

regulatory changes.

These contractual provisions are critical because storage introduces risks that did not exist in a conventional wind PPA.

12. Case Law: Energy Watchdog

Energy Watchdog v. CERC, (2017) 14 SCC 80

This is one of the most important Supreme Court decisions for electricity PPAs.

The Court examined the relationship between:

Section 63;

competitive bidding;

PPAs;

change in law; and

regulatory powers.

The broader principle is that where electricity tariff has been discovered through competitive bidding, contractual and statutory provisions governing changes to that tariff become particularly important.

This principle is directly relevant to wind-storage projects because many new renewable-plus-storage projects are procured through competitive bidding.

13. Case Law: Uttar Haryana Bijli Vitran Nigam Ltd.

Uttar Haryana Bijli Vitran Nigam Ltd. v. CERC

The case involved the limits of regulatory intervention in competitively discovered tariffs.

The judgment emphasised that a tariff determined under Section 63 cannot ordinarily be reopened merely because a regulator considers an alternative tariff desirable. Relief must generally be grounded in applicable contractual provisions such as Change in Law or Force Majeure. (Indian Kanoon)

Relevance to wind-storage projects

Suppose a developer bids for:

₹4.50/kWh firm renewable power

based on assumptions concerning:

battery cost;

taxes;

transmission;

storage degradation;

charging electricity;

financing.

A subsequent regulatory change increases project costs.

The developer cannot simply demand a new tariff merely because the economics have deteriorated. The claim would have to be examined under the applicable PPA and legal framework.

14. Case Law: Jaipur Vidyut Vitran Nigam Ltd. v. Adani Power Rajasthan Ltd.

In Jaipur Vidyut Vitran Nigam Ltd. v. Adani Power Rajasthan Ltd., the Supreme Court examined a competitively bid PPA and claims for tariff adjustment under its change-in-law provisions. (Indian Kanoon)

Although the project involved conventional generation rather than wind-storage, the contractual principle is highly relevant.

Application to wind-storage

A wind-storage PPA should precisely identify events such as:

change in storage taxation;

new battery-related regulatory charges;

changes in transmission charges;

new grid-code obligations;

changes affecting renewable attributes.

Otherwise, disputes may arise over whether a regulatory change actually qualifies as a contractual Change in Law.

15. Case Law: M.P. Power Management Co. Ltd. v. Sky Power Southeast Solar India Pvt. Ltd.

The Supreme Court considered a renewable-energy PPA and the statutory structure of competitive bidding under Section 63.

The Court explained that Section 63 requires adoption of a tariff determined through a transparent bidding process conducted in accordance with Central Government guidelines. (Indian Kanoon)

Importance

The case demonstrates that renewable-energy PPAs cannot be analysed purely as ordinary commercial contracts. They operate within the statutory architecture of the Electricity Act and applicable bidding guidelines.

For hybrid wind-storage projects, the same principle applies.

16. Recent CERC Developments

The regulatory framework is rapidly evolving.

CERC's recent orders show increasing involvement of storage and hybrid projects.

For example, CERC's September 2026 orders include proceedings concerning:

wind-solar hybrid projects;

renewable projects with ESS;

tariff adoption for wind-solar hybrid projects; and

conversion of wind connectivity capacity into battery storage capacity. (CERC)

This indicates that storage is increasingly being treated as an integrated element of India's electricity infrastructure rather than merely as an ancillary technology.

17. Key Regulatory Issues

18. Legal Challenges

A. Double counting of renewable attributes

If wind electricity is stored and later discharged, regulators must determine how renewable attributes are counted.

A robust framework should prevent the same renewable electricity from generating multiple renewable benefits.

B. Charging from the grid

If the battery charges partly from wind and partly from grid electricity, the legal classification of discharged electricity becomes more complicated.

The regulatory system therefore needs transparent:

metering;

accounting;

tagging; and

renewable-energy attribute rules.

C. Battery degradation

Battery capacity declines over time.

Therefore, a 100 MW/200 MWh battery at commissioning may not provide the same capacity after several years.

Contracts must determine:

augmentation;

replacement;

performance guarantees;

degradation limits; and

availability obligations.

D. Market participation

A wind-storage system may potentially participate in multiple markets:

energy market;

capacity/flexibility services;

ancillary services;

balancing mechanisms;

bilateral PPAs.

Regulation must prevent conflicting obligations.

19. International Comparative Perspective

Other jurisdictions are also developing regulatory frameworks for hybrid renewable-storage systems.

The central regulatory questions internationally include:

Is storage legally generation, consumption, or both?

Can storage receive renewable-energy incentives?

How are grid charges imposed?

How is renewable electricity tracked after storage?

Can storage participate simultaneously in energy and ancillary-service markets?

Who controls dispatch?

How are interconnection rights allocated?

The Indian framework is evolving toward an integrated model in which renewable generation and storage can be recognised at the same interconnection point.

20. Suggested Regulatory Model for India

A mature wind-storage regulatory framework should provide:

1. Clear asset classification

Legally recognise integrated renewable-storage facilities.

2. Single-point interconnection

Permit wind and storage to use common grid infrastructure where technically appropriate.

3. Separate metering

Measure:

wind generation;

battery charging;

battery discharge;

grid import; and

grid export.

4. Clear renewable accounting

Establish rules for renewable-energy attributes after storage.

5. Firm-power procurement

Permit competitive procurement of firm renewable power backed by storage.

6. Transparent DSM rules

Provide predictable treatment of charging, discharging and deviations.

7. Curtailment rules

Protect renewable priority while preserving legitimate grid-security exceptions.

8. Battery performance standards

Establish minimum requirements for:

availability;

response time;

efficiency;

degradation; and

safety.

9. Standardised PPA provisions

Develop model clauses dealing with storage-specific risks.

10. Regulatory coordination

CERC, SERCs, Grid-India, CTU/STUs, DISCOMs and renewable agencies should operate under consistent rules.

21. Conclusion

Hybrid Renewable System Regulation (Wind + Storage) represents a transition from regulation of individual generating technologies toward regulation of integrated, flexible electricity systems.

The principal legal architecture in India is derived from the Electricity Act, 2003, CERC regulations, Central Government competitive-bidding guidelines, grid-code and deviation-settlement frameworks, and project-specific PPAs.

CERC's 2024 Renewable Energy Tariff Regulations expressly recognise renewable-energy-with-storage projects, while its deviation framework provides specific treatment for renewable sellers with ESS at a common interconnection point. (CERC)

The jurisprudence surrounding Energy Watchdog, Uttar Haryana Bijli Vitran Nigam, Jaipur Vidyut Vitran Nigam, and renewable-energy PPA disputes establishes an important principle: the technological sophistication of a hybrid project does not displace the statutory and contractual framework governing tariff, bidding, change in law and PPA performance. (Indian Kanoon)

The future legal challenge is therefore to construct a framework in which wind generation, storage, market participation and grid reliability can operate as one coordinated legal and technical system, while maintaining transparent metering, fair allocation of costs and risks, renewable-energy integrity, and grid security.