What is null power (Scope 2)?
Null power is electricity left after its energy attribute certificates, or other instruments carrying the generation attributes, are separated and sold. The electricity user can no longer claim that its source is renewable or use the greenhouse gas emissions rate carried by the sold instrument. The GHG Protocol also calls the remaining electricity commodity electricity. This changes the market-based calculation within Scope 2 emissions.
Why does null power matter to you?
If your company consumes electricity from its own solar system or through a direct line but sells the certificates, you cannot report that electricity as renewable or apply the solar facility's zero-emissions rate. A customer checking your renewable-electricity figure may ask for the consumed MWh, certificate quantity, serial numbers, transfer record, reporting period, and the factor used instead.
How does null power work?
First, match the certificates sold or transferred to the megawatt-hours (MWh) generated and consumed. For those MWh, use another source allowed in the market-based calculation. This may be replacement certificates, an eligible supplier-specific emissions rate, or the residual mix, which is the factor for electricity left after claimed attributes are removed. Use the grid-average factor for the location-based total. Keep the two totals separately labelled.
What mistakes should you avoid?
- Claiming on-site electricity as renewable after selling its certificates.
- Applying the generator's emissions rate to both the certificate buyer and the electricity user.
- Ignoring a partial certificate sale and treating every MWh alike.
- Using a residual-mix factor without recording its geography, year, value, and unit.
Does selling some certificates make all generation null power?
No. Match the sold certificate quantity to the same quantity of electricity. Only that portion loses the transferred attributes. Keep records showing which certificates, MWh, market, and generation period remain available for your claim.
What should you send when a customer checks the claim?
Send meter records, the certificate issuance and sale records, serial numbers, MWh reconciliation, the residual-mix or replacement-factor source, and both labelled Scope 2 calculations.