1. Meaning and concept

Time-of-Generation Value Pricing (TGVP) is an electricity-pricing approach under which the economic value of electricity depends on when it is generated, as well as how much electricity is produced.

The central principle is that one unit of electricity does not necessarily have the same system value at every hour of the day. A unit generated during peak demand may avoid expensive power purchases, reduce the need for peaking plants, or improve grid reliability. A unit generated when electricity supply is already abundant may have a lower market value.

The expression Time-of-Generation Value Pricing is best understood as an analytical concept, rather than the name of one universally established legal doctrine. Its legal implementation may occur through time-of-day tariffs, time-block electricity markets, ancillary-service payments, renewable-energy contracts, and other regulatory mechanisms.

Example

Illustrative electricity values — not actual market quotations

Midday: abundant solar generation

₹2.50/kWh

Illustrative market value during high supply and lower net demand.

Evening: high demand, lower solar output

₹8.00/kWh

Illustrative value during a period of tighter supply and higher demand.

The difference reflects the assumed value of electricity in each time period. Actual prices depend on the market, location, transmission constraints, contracts and regulatory rules.

A solar generator producing electricity at midday and a flexible generator supplying power in the evening may therefore contribute different economic value to the electricity system, even if both produce the same number of units.

Importantly, a higher market value does not automatically mean that the generator is legally entitled to a higher tariff. The applicable contract and regulatory framework determine the payment.

2. How time-of-generation value pricing works

The concept has five principal components.

A. Temporal value

Electricity demand and supply change throughout the day. Prices may vary across 15-minute, half-hourly, hourly or other applicable settlement intervals.

Peak periods: Higher demand or limited supply can increase electricity prices.

Off-peak periods: Lower demand may reduce the value of additional generation.

Renewable-rich periods: High solar or wind output may reduce market prices when supply is abundant.

Scarcity periods: Limited available generation or transmission capacity may increase the value of electricity that can be delivered reliably.

B. Marginal system cost

A useful economic measure is the marginal cost of serving an additional unit of demand at a particular time and location.

If an additional unit of low-cost electricity avoids operating an expensive peaking generator, it can create substantial system savings. However, the actual value may be affected by congestion, losses, reserve requirements and the availability of storage.

C. Dispatchability and flexibility

Generation that can respond when demand rises may have additional value beyond its energy output.

For example, a battery may charge during a low-price period and discharge during a high-price period. Its value comes from the difference between those periods, after accounting for efficiency losses, degradation, charging costs and market rules.

D. Reliability value

Electricity supplied during a system emergency or scarcity period may help avoid load shedding or costly emergency procurement. Such value is not necessarily captured by the ordinary energy price; separate capacity or ancillary-service mechanisms may be relevant.

E. Contractual value

A power purchase agreement (PPA) may provide a fixed tariff, a time-dependent tariff, a variable market-linked payment, or a combination of these.

Consequently, the same generator can have a different economic system value from its contractual revenue.

3. Legal framework in India

India does not rely on a single legal provision called Time-of-Generation Value Pricing. Instead, several provisions of the electricity-law framework support related pricing mechanisms.

The statutory provisions are available in the Electricity Act and the Government's published materials.

Electricity Department

+2

Time-of-Day tariffs: a direct practical example

The Ministry of Power's 2023 announcement explained that time-of-day (ToD) tariffs would vary by period: solar-hour tariffs would be lower than normal tariffs, while peak-period tariffs would be higher. The rules also established implementation timelines and differentiated peak-period requirements for consumer categories.

Press Information Bureau

+1

This is an important distinction:

Time-of-generation pricing evaluates the value of electricity when a generator produces it.

Time-of-day pricing changes the price charged to consumers according to the time they consume electricity.

Time-block wholesale pricing values electricity traded in specific market intervals.

Contractual generation tariffs determine the revenue payable to a generator under the applicable PPA or regulatory order.

These mechanisms can reinforce one another, but they are not legally interchangeable.

4. Important case laws and their relevance

The following decisions establish legal principles relevant to time-dependent electricity valuation, tariff setting and the limits of regulatory discretion. They should not be read as holding that Indian law independently recognises a general right to Time-of-Generation Value Pricing.

Case 1: Gujarat Urja Vikas Nigam Ltd. v. Tarini Infrastructure Ltd.

Supreme Court of India · 2016 · (2016) 8 SCC 743

Facts: The dispute concerned a small hydroelectric project in Gujarat. The generator sought a higher tariff after discovering that the transmission connection would require substantially more infrastructure than originally anticipated. The existing PPA contained a specified tariff and escalation arrangement.

Legal question: Is a tariff incorporated into a PPA absolutely immune from review by the State Electricity Regulatory Commission?

Principle: The Supreme Court examined the statutory powers of the regulatory commission to review or correct tariff in the circumstances permitted by law and the applicable contractual and regulatory framework.

Indian Kanoon

+1

Relevance to time-of-generation value pricing: A generator's costs, operational circumstances and market value may change over time. However, a later increase in market prices does not automatically entitle the generator to reopen a fixed tariff. The legal basis for any revision must be found in the statute, applicable regulations, tariff order or contract.

Practical lesson: Separate the changing market value of electricity from the legal right to receive a particular tariff.

Case 2: U.P. Power Corporation Ltd. v. NTPC Ltd.

Supreme Court of India · 2009 · (2009) 6 SCC 235

Facts: The litigation concerned whether additional expenditure arising from retrospective revisions to employee pay scales could be included in revisions to NTPC's electricity tariff for earlier tariff years.

Legal question: Can additional costs arising after the original tariff calculation automatically justify retrospective tariff revision?

Principle: The Court considered the statutory and regulatory basis for incorporating the disputed expenditure into tariff. The case illustrates that cost recovery and tariff adjustments must follow the governing legal framework rather than occurring automatically merely because costs have changed.

Indian Kanoon

+1

Relevance to TGVP: Time-sensitive electricity prices and generation costs are not interchangeable. A generator may experience higher costs or higher market prices during certain periods, but the financial consequences depend on the applicable tariff methodology and contract.

Practical lesson: Dynamic pricing requires an authorised methodology for calculating and settling the price; it cannot be created merely by asserting that the value of electricity has changed.

Case 3: PTC India Ltd. v. Central Electricity Regulatory Commission

Supreme Court of India · 2010 · (2010) 4 SCC 603

Legal significance: This judgment is an important authority on the statutory and regulatory framework governing electricity regulation, including the character of regulations made by the Central Electricity Regulatory Commission and the relationship between regulations and adjudicatory orders.

Relevance to TGVP: A time-based pricing system must operate within the applicable regulatory framework. Where a commission prescribes binding tariff or market rules, individual orders and contractual arrangements must be assessed against those rules.

The broader principle is that an economically attractive pricing model does not become legally enforceable merely because it might improve grid efficiency. Its implementation must comply with the relevant statutory powers and regulations.

For research, the judgment should be read alongside Sections 61–64 and 79 of the Electricity Act, 2003.

Case 4: A.P. TRANSCO v. Sai Renewable Power (P) Ltd.

Supreme Court of India · 2010 · (2010) 10 SCC 280

Legal significance: This authority is relevant to the statutory nature of tariff determination and regulatory arrangements for renewable-energy procurement.

Relevance to TGVP: Renewable electricity can have different system values at different times, but renewable-energy promotion and tariff determination must be considered within the governing statutory framework. A court's recognition of regulatory tariff-setting powers does not, by itself, establish that every renewable generator must receive a higher price during peak hours.

For a specific dispute, the judgment should be read with the relevant State Commission's renewable-energy regulations, the applicable tariff order and the executed PPA.

Case 5: Southern Power Distribution Company of Andhra Pradesh Ltd. v. Green Infra Wind Solutions Ltd.

Supreme Court of India · 25 March 2026

This recent decision addresses whether a State Electricity Regulatory Commission can factor a generation-based incentive into the tariff payable to renewable-energy generators. The dispute concerned an incentive designed to encourage actual renewable generation and whether the distribution companies could deduct that incentive from tariff payments.

The judgment discusses the distinction between a tariff determined under the statutory regulatory framework and a separate incentive scheme.

SCI API

+1

Relevance to TGVP: This is particularly useful when distinguishing between:

the tariff payable for electricity generated;

a separate incentive linked to generation;

the economic value of generation at a particular time; and

the legal authority to adjust or deduct payments.

The decision should be read in full before applying it to a time-linked tariff dispute. It does not automatically establish a general peak-hour premium for generators.

Case 6: GRIDCO Ltd. v. Western Electricity Supply Co. of Orissa Ltd.

Supreme Court of India · (2024) 2 SCC 500

This decision is relevant to the statutory framework for electricity regulation and the allocation of functions between regulatory commissions and electricity-sector entities.

Aptel

Relevance to TGVP: Time-based pricing requires coordination among generators, distribution companies, market operators and regulators. A pricing formula must be implemented through the applicable legal and contractual arrangements rather than through an informal reallocation of costs.

Its application to any specific time-block pricing dispute depends on the issue decided and the relevant regulatory provisions.

For authoritative research, the official Supreme Court and Appellate Tribunal for Electricity (APTEL) judgment databases are useful starting points.

APPELLATE TRIBUNAL FOR ELECTRICITY

+1

5. Mathematical model of time-of-generation value pricing

A simplified model can express the economic value of electricity produced in each time interval.

\[ V_t=E_t \times P_t \]

Where:

\(V_t\) = gross energy value during interval \(t\)

\(E_t\) = electricity generated during that interval, in kWh

\(P_t\) = applicable price or estimated system value per kWh

For a generator producing electricity over multiple intervals:

\[ V_{\text{total}}=\sum_{t=1}^{n} E_tP_t \]

This represents gross energy value, not necessarily the amount the generator receives under its PPA.

Worked example

Assume a generator produces 100 kWh in each of three periods, at illustrative market prices.

The weighted average price is:

\[ \frac{₹1,450}{300}=₹4.83/\text{kWh} \]

The calculation illustrates how the timing of generation affects gross market value. It does not establish the generator's actual contractual revenue, which may instead be determined by a fixed tariff or another settlement mechanism.

A more complete economic assessment would subtract operating costs, storage losses, transmission charges and other applicable costs, while separately valuing flexibility and reliability services where justified.

6. Advantages and disadvantages

Advantages

Encourages generation when electricity is more valuable to the system.

Can reward batteries and flexible generation for shifting supply across time.

Can encourage consumers to move discretionary consumption away from peak periods.

May improve the use of transmission capacity and reduce costly emergency procurement.

Can make the economic benefits of flexibility more visible.

Disadvantages and risks

Prices can become volatile during scarcity periods.

Solar generators may receive low market prices during periods of abundant solar output.

Consumers with little ability to change their usage may face higher bills.

Inaccurate forecasts can cause generators or storage operators to make inefficient decisions.

Poorly designed pricing can create incentives that conflict with grid reliability or renewable-energy goals.

7. Application to renewable energy and storage

Solar power

Solar generation often peaks during daylight hours. When solar output is abundant, the market value of additional generation can fall. Storage, demand response and transmission expansion may help move electricity's use or delivery toward more valuable periods.

Wind power

Wind output depends on weather and location. Its time-dependent value therefore depends on whether production coincides with demand, available transmission capacity and the output of other generators.

Battery storage

Batteries can purchase or absorb electricity during lower-value periods and discharge during higher-value periods. The economic opportunity is the price spread after accounting for losses, degradation and other costs.

8. How a regulator could design a lawful pricing framework

A regulator considering time-of-generation value pricing could proceed through the following steps:

Define the objective. Determine whether the goal is to reduce peak costs, encourage flexibility, support renewable integration or improve reliability.

Specify the settlement interval. Define the relevant time blocks, metering standards and settlement rules.

Select the valuation method. Use an appropriate market price, avoided-cost calculation or approved tariff methodology.

Allocate risks transparently. Clarify who bears price, forecast, imbalance and curtailment risks.

Protect consumers. Evaluate affordability, essential electricity use and the ability of different consumer groups to respond to price signals.

Align the contract and regulations. Ensure that the PPA, tariff order, metering rules and market-settlement framework support the intended arrangement.

Review performance. Measure whether the scheme actually reduces total system costs and improves reliability.

The Electricity Act's tariff principles and the applicable CERC or State Commission regulations provide the legal starting point for such a design.

Electricity Department

+2

9. Key legal distinction: economic value versus enforceable tariff

Conclusion

Time-of-Generation Value Pricing is a framework for recognising that the value of electricity depends partly on the time at which it is produced and delivered. It connects electricity economics with tariff regulation, renewable-energy integration, storage and grid reliability.

In India, the strongest legal foundation lies in the Electricity Act, 2003, applicable time-of-day rules, regulatory tariff orders, market regulations and contractual arrangements. The Supreme Court decisions discussed above help explain regulatory authority and the limits of tariff revision; they should not be treated as direct judicial recognition of a standalone TGVP doctrine.

For an actual legal dispute, the decisive questions are which commission has jurisdiction, which tariff regulations apply, what the PPA says about price and revision, and whether the proposed time-dependent payment is authorised by law.

This is a general legal explanation, not a case-specific legal opinion. Exact holdings and current applicability should be verified against the full judgments and regulations.