Carbon Reporting and Renewable Energy Certificates

Electricity consumption is one of the most visible emission sources in carbon reporting processes. For businesses, renewable energy use has become strategic not only for cost, but also for reporting, customer expectations, export markets and supply-chain compliance.

In this process, accuracy of consumption data, energy source used and traceability of certificate documents are critical.

Electricity Consumption and Scope 2

Indirect emissions from electricity consumption are generally evaluated under Scope 2. The source of electricity purchased by the business can affect the reported emission amount.

Therefore, consumption data should be kept regularly by location, period and meter. In multi-location structures, a single total consumption table is not enough; each subscription’s consumption period, tariff group, invoice start-end date and, if any, generation/settlement effect should be tracked separately.

Scope 2 reporting is usually read through two approaches. The location-based approach uses the average emission factor of the electricity system to which the facility is connected; in other words, it shows the carbon intensity of the grid physically used by the business. The market-based approach considers purchased renewable energy, certificate use or supply contract. Documents such as I-REC or YEK-G become meaningful on this second side, but if document period, quantity and consumption matching are not built correctly, reporting reliability weakens.

Renewable Energy Certificates

Renewable energy certificates are used to document that consumed electricity is matched with renewable sources. When managing certificates, document period, consumption amount and reporting standard should be compatible.

A certificate does not create technical efficiency by itself; however, it creates traceability and claim reliability on the reporting side. A certificate does not replace an energy efficiency project or solar investment. The more accurate statement is this: a certificate is a reporting tool showing that consumed electricity is environmentally matched with a specific renewable generation.

Companies in Türkiye use these documents with different motivations. Some institutions want to meet renewable energy expectations from supply-chain customers. Some manage the market-based Scope 2 calculation in their sustainability report. For export manufacturers, whether environmental claims are accepted in customer audits is another topic. Therefore, certificate purchase should not be treated only as buying a "green energy document"; it should be clear from the beginning which report, which customer or which period it will be used for.

The critical point here is double counting risk. The same renewable generation attribute should not be claimed by more than one consumer. For this reason, certificate cancellation, consumption period and document records should be stored regularly.

How Are I-REC and YEK-G Positioned?

I-REC is one of the renewable energy certificate mechanisms frequently used by companies with international reporting. YEK-G is Türkiye’s renewable energy resource guarantee certificate system in the electricity market. Both structures aim to associate electricity consumption with renewable sources; however, their usage purpose, accepted reporting framework and operational process may differ.

Before certificate purchase, the reporting need should be defined first. Does the customer request I-REC, is local YEK-G sufficient, or is a specific methodology followed for the company’s own sustainability report? Then consumption amount should be clarified in MWh, certificate period should be matched with consumption period, and cancellation records should be available for audit.

Relationship with Solar Investment

For businesses that make their own solar investment, generation data, consumption data and settlement structure should be reported together. This way, both cost impact and sustainability contribution are shown more clearly.

However, there is an important distinction here as well. If the electricity generated by rooftop solar is consumed instantly by the same facility, this may be evaluated as a physical consumption effect. Surplus generation delivered to the grid, settlement, sale or certificate claim should be checked separately. Writing generation data directly as "carbon reduction" can produce incorrect results if consumption matching and reporting methodology are ignored.

For solar-owning institutions, the backbone of the reporting file is hourly generation and consumption records for the same period. Settlement notifications, surplus generation records, certificate generation/transfer/cancellation if any, and production loss notes due to maintenance should be added. A file built this way connects both financial impact and sustainability claim to the same source data.

How Should Audit-Ready Data Be Kept?

In carbon reporting, the main problem is often not the calculation formula, but retrospective traceability of data. When invoices, meter data, certificate records and consumption tables are kept by different teams, reconciliation at the end of the reporting period becomes difficult.

For an audit-ready structure, subscription and meter inventory is prepared first. Then monthly consumption is recorded with the invoice period; solar generation, settlement and surplus production are tracked in separate rows. On the certificate side, quantity, generation source, consumption period and cancellation document should be kept in the same folder. When the emission factor and methodology note used in the report are also included, sustainability teams and finance/operations teams can use the same data.

Conclusion

Carbon reporting cannot be separated from energy management discipline. Correct measurement, correct supply and correct certificate management should work on the same data infrastructure.

The healthiest approach is to treat the certificate not as a document purchased afterward, but as part of the annual energy management plan. When consumption, generation, supply and reporting are managed on the same calendar, the sustainability claim becomes stronger and more auditable.