Certification of sustainable biomethane: ISCC, REDcert, mass balance and voluntary markets

For biomethane to count towards renewable targets in the EU or be sold as a sustainable fuel, its producer and the whole supply chain must be certified in a scheme recognised by the European Commission – in practice most often ISCC EU or REDcert-EU. Certification confirms that the feedstocks meet the criteria of the RED directive, that the installation achieves the required reduction in GHG emissions and that quantities are tracked at every stage by means of mass balance. The audit is carried out by an independent certification body, usually annually.

What certification covers

1. Feedstocks: confirmation that the biomass comes from permitted sources (wastes, residues, crops meeting land-use criteria), together with suppliers' documents and declarations.
2. GHG emissions: calculation or adoption of default values and comparison with the fossil fuel comparator.
3. Mass balance: a register of inputs and outputs that makes it possible to assign the sustainability characteristics of a batch of feedstock to a batch of product.
4. Chain of custody: every participant who holds physical or legal title to the feedstock or product should hold a certificate or be covered by a group certificate.
5. Documentation: sustainability declarations, proofs of sale, a register of corrections.

Certification path

The cost depends on the size of the installation, the number of substrate suppliers and the scope of the chain; it includes scheme and audit fees.

Mass balance

The mass balance method allows batches with different characteristics to be mixed in a single store or grid, provided that the output quantities correspond to the input quantities, taking conversion factors into account. In grid gas, mass balance makes it possible to assign the sustainability characteristic to biomethane injected in one place and withdrawn in another, without physically distinguishing the molecules. This is the basis of cross-border biomethane trade in the EU, provided that national schemes and registers recognise it.

Voluntary markets

Beyond legal obligations there are voluntary schemes in which customers want to confirm the "greenness" of gas, e.g.:

• ISCC PLUS – a scheme outside the regulated EU markets, used, among others, in the chemical industry;
• national biogas registers, such as the German biogas register run by dena or the Dutch Vertogas certificates;
• the European Renewable Gas Registry, ERGaR.

These schemes have their own rules on criteria and verification; it is important for the customer to know which standard has been met, because it determines whether the gas can be counted towards regulatory targets.

Certificate versus guarantee of origin

A sustainability certificate states that the biomethane meets the RED criteria (feedstocks, GHG) and can count towards regulatory targets; a guarantee of origin states only that a given quantity of energy comes from renewable sources and is used to declare consumption at the customer's end. In practice both documents are often required, but they are not interchangeable.

Example of cost per unit

Let us assume (for illustration) that the annual cost of certification and audit is PLN 60 thousand and production is 30 GWh. The cost per MWh: 60,000/30,000 = PLN 2/MWh, or PLN 0.02/m³ (at a biomethane calorific value of about 10 kWh/m³). This is a small part of the price, but the lack of a certificate can strip the product of several dozen percent of its value. For this reason the cost of certification is treated as an indispensable element of the business plan.

Risks

• missing documents from substrate suppliers,
• errors in the mass balance,
• a change in scheme requirements,
• audit delays,
• discrepancies between measurement data and declarations.

Choosing the scheme and the certification body

When choosing a scheme, check whether it is recognised by the European Commission for your use (transport, heat, electricity), whether it covers your suppliers and customers, and what the costs and timelines are. The certification body is chosen from the list authorised by the scheme; it is worth comparing offers, experience in biogas and availability in the country. Ask for the scope of the audit, the required documents and a sample schedule in order to avoid surprises. A good step is a pre-audit, which reveals gaps in documentation before the actual certification begins.

Summary

Certification is a condition for recognising biomethane as a sustainable fuel and the basis of its commercial value. It is best to implement a record-keeping system from the first day of the installation's operation and to cooperate with the certification body already at the preparation stage.