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Renewable Energy Certificates (RECs) represent one of the most underutilized revenue streams available to solar system owners in India. While most rooftop solar adopters focus on electricity bill savings and net metering benefits, RECs offer an additional income opportunity — particularly for commercial and industrial solar installations that generate surplus green energy.
RECs are market-based instruments that separate the "green" attribute of renewable energy from the physical electricity. Each REC represents 1 MWh (1,000 units) of electricity generated from a renewable source. These certificates can be traded on the Indian Energy Exchange (IEX) and Power Exchange India Limited (PXIL), allowing solar generators to monetize their environmental contribution beyond simple energy savings.
This guide explains how RECs work, who can earn and trade them, the current market dynamics, and how Tamil Nadu solar system owners can participate in this growing market.
How Renewable Energy Certificates Work
The Basic Concept
When a solar system generates electricity, it produces two things:
- Physical electricity — which is consumed on-site, exported to the grid, or both
- Environmental attribute — the "greenness" of that electricity, representing avoided carbon emissions and fossil fuel displacement
A REC captures and certifies the environmental attribute. The physical electricity and its green attribute can be "unbundled" — meaning a factory in Maharashtra can buy RECs from a solar generator in Tamil Nadu to claim renewable energy usage, even though the physical electrons flow locally.
Types of RECs in India
The Central Electricity Regulatory Commission (CERC) recognizes two categories:
| Type | Source | Floor Price (2025-26) | Ceiling Price (2025-26) |
|---|---|---|---|
| Solar REC | Solar energy generation | Rs 0 (floor removed) | Rs 1,000/MWh |
| Non-Solar REC | Wind, biomass, small hydro, etc. | Rs 0 (floor removed) | Rs 1,000/MWh |
Important change: CERC removed the floor price for RECs in 2023, making the market entirely demand-supply driven. This means prices can be low during periods of oversupply, but can rise significantly when demand exceeds availability — particularly near the end of compliance periods.
Who Can Earn RECs?
Eligibility Criteria
To earn RECs, a renewable energy generator must meet these conditions:
- The generation facility must be registered with the State or Central Electricity Regulatory Commission as a renewable energy generator
- The electricity must not already be counted towards any state's Renewable Purchase Obligation (RPO) — this is critical. If your solar electricity is consumed through net metering and already counted towards TANGEDCO's RPO compliance, you cannot also earn RECs for the same generation
- The generator must register on the REC Registry maintained by the Central Agency (REC Registry of India, operated by NLDC/POSOCO)
Practical Eligibility for Different Solar Installations
| Installation Type | REC Eligibility | Notes |
|---|---|---|
| Net-metered rooftop solar (residential) | Generally No | Generation is counted towards DISCOM's RPO |
| Captive solar (consumed on-site without net metering) | Possible | If not counted towards state RPO compliance |
| Open access solar (third-party sale) | Yes | Common route for large generators |
| Ground-mount solar plants (independent power producer) | Yes | Standard route for utility-scale solar |
| Off-grid solar systems | No | Not connected to the grid |
The RPO Connection
Renewable Purchase Obligation (RPO) requires electricity distribution companies (like TANGEDCO) and large consumers (open access and captive consumers) to purchase or generate a specified percentage of their total electricity from renewable sources. For FY 2025-26, the all-India RPO target is approximately 43% (combined solar and non-solar).
Entities that fall short of their RPO targets must purchase RECs to make up the deficit. This creates the demand side of the REC market.
The REC Trading Process
Step 1: Registration
The solar generator registers with the State Nodal Agency (TEDA — Tamil Nadu Energy Development Agency, in Tamil Nadu's case) and the REC Registry.
Documents required:
- Power Purchase Agreement or grid connectivity agreement
- CERC/TNERC registration as a renewable energy generator
- Commissioning certificate
- Generation meter details
- Bank account details for settlement
Step 2: Issuance
Each month, the generator reports electricity generation data to the State Nodal Agency. After verification, the agency issues RECs to the generator's account in the REC Registry.
- 1 REC = 1 MWh (1,000 kWh) of solar generation
- RECs are issued monthly based on verified generation data
- Fractional generation (less than 1 MWh) is carried forward to the next month
Step 3: Trading
RECs are traded on two power exchanges in India:
- Indian Energy Exchange (IEX) — the larger and more liquid exchange
- Power Exchange India Limited (PXIL) — the alternative exchange
Trading sessions are conducted on the last Wednesday of every month (or as scheduled by the exchanges). Generators list their RECs for sale, obligated entities bid to purchase, and the exchange determines the clearing price through a double-sided auction mechanism.
Step 4: Settlement
After a successful trade, the exchange settles the transaction:
- The buyer receives the RECs in their REC Registry account
- The seller receives the sale proceeds (minus exchange transaction fees of approximately 1-2%)
- The buyer uses the RECs to demonstrate RPO compliance
Current Market Dynamics (2026)
Price Trends
REC prices have been volatile since the removal of the floor price:
- 2023-24: Prices dropped significantly after floor price removal, trading between Rs 100-300/MWh
- 2024-25: Gradual recovery as RPO enforcement tightened, with prices averaging Rs 200-500/MWh
- 2025-26: Market stabilizing with increased RPO targets and stricter compliance enforcement by state regulators
Demand Drivers
Several factors are increasing demand for RECs:
- Rising RPO targets: The trajectory towards 43% by 2030 means more entities need to comply
- Corporate sustainability commitments: Indian and multinational companies are voluntarily purchasing RECs to meet RE100 and ESG commitments
- BRSR (Business Responsibility and Sustainability Reporting): SEBI-mandated reporting for top listed companies creates additional demand
- Green tariff limitations: Not all states offer green tariff options, making RECs the alternative route for green claims
Supply Factors
- Rapid growth in solar installations across India has increased REC supply
- Many large solar plants now sell power through PPAs that include bundled RECs, reducing the tradeable surplus
- States with strong RPO enforcement (like Tamil Nadu) have fewer unmatched RECs available
Revenue Potential for Tamil Nadu Solar Installations
Example Calculation
Consider a 500 kW commercial rooftop solar installation in Coimbatore:
| Parameter | Value |
|---|---|
| Annual generation | 7,50,000 units (750 MWh) |
| Self-consumption | 80% (6,00,000 units) |
| Surplus exported to grid (net metered) | 1,50,000 units |
| RECs eligible (if registered) | Up to 750 RECs/year |
| REC trading price (conservative) | Rs 300/REC |
| Potential annual REC revenue | Rs 2,25,000 |
Note: This revenue is in addition to the electricity savings from the solar system. However, eligibility depends on how the generation is classified under RPO rules — consult with your regulatory advisor.
Voluntary RECs and International Markets
I-RECs (International RECs)
For solar generators looking beyond the domestic REC market, the International REC (I-REC) system offers an alternative. I-RECs are recognized globally and can be sold to multinational corporations seeking to offset their Indian operations' carbon footprint.
- I-REC prices: Currently Rs 150-400 per MWh, varying by vintage and buyer requirements
- Registration: Through I-REC Standard and authorized local issuers
- Buyers: Multinational tech companies, financial institutions, and manufacturing companies with global sustainability targets
Carbon Credits vs RECs
RECs and carbon credits are related but distinct instruments:
- RECs certify renewable energy generation (1 REC = 1 MWh)
- Carbon credits certify emission reduction (1 credit = 1 tonne CO2 avoided)
- A solar system can potentially earn both, but double-counting must be avoided
- The Verified Carbon Standard (VCS) and Gold Standard offer carbon credit certification for solar projects
Practical Considerations for Tamil Nadu Solar Owners
Is REC Trading Worth It for Small Systems?
For residential and small commercial systems (below 50 kW), the administrative effort of REC registration and monthly trading may not justify the revenue. The process involves regulatory registration, monthly generation reporting, and exchange membership — overhead that makes sense only at scale.
Rule of thumb: REC trading becomes financially attractive for systems above 100 kW generating 1,50,000+ units annually.
Tax Treatment of REC Income
REC trading income is treated as business income and taxed at the applicable rate. For companies, this falls under normal corporate tax. For individuals operating solar as a business, it is taxed under "Profits and Gains from Business or Profession."
Combining RECs with Other Benefits
Solar system owners must be careful not to "double-count" green attributes:
- If your generation is net-metered and counted towards TANGEDCO's RPO, you generally cannot also earn RECs
- If you consume power through captive mode and forgo RPO counting, you can earn RECs
- Consult TNERC guidelines and a regulatory advisor for your specific situation
Getting Started with REC Trading
If you operate a large commercial or industrial solar installation in Tamil Nadu and want to explore REC trading as an additional revenue stream, the first step is understanding your eligibility based on how your generation is classified under RPO rules.
Use our solar savings calculator for an overall financial assessment of your solar investment, or contact Tristar's team to discuss REC eligibility and the registration process. We can connect you with REC trading advisors and help you evaluate whether this revenue stream makes sense for your installation size and configuration.
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