Guarantee of Origin (GoO)

A Guarantee of Origin (GoO; Estonian päritolutunnistus) is an electronic certificate that Elering issues to a generator on application, attesting that one MWh of electricity was produced from a renewable source or in efficient cogeneration. The instrument is created under EU Renewable Energy Directive Article 19 (RED II) — the directive uses the alternate Estonian term päritolutagatis.

How it works

One certificate represents one MWh of renewable generation. The generator can sell the certificate separately from the underlying electricity — to a corporate buyer that wants to claim renewable consumption, to a utility for residual-mix labelling, or via the AIB (Association of Issuing Bodies) cross-border registry to buyers in other EU countries. Estonia joined AIB in 2014, and Elering's GoO register is interoperable with the rest of Europe.

Why corporates buy them

Voluntary disclosure (CDP, RE100, EU CSRD) requires companies that claim renewable electricity consumption to back the claim with cancelled GoOs equal to their consumption. Without GoOs, the residual mix applies — the average emissions content of unspecified electricity, which in Estonia historically has been carbon-heavy due to oil shale. A 1 GWh data centre that wants to call itself "100% renewable" needs 1,000 GoOs cancelled in the same compliance year. GoOs are also priced into PPA contracts; a corporate PPA with embedded GoO transfer is the cleanest way to lock in both physical electricity and the green claim simultaneously.