The introduction and rapid spread of green electricity as a specific product has triggered a sequence of changes in Dutch electricity supply and green electricity trade and even has impacted European energy policy. Triggered by fundamental changes in the electricity sector it led to new governance arrangement for the product green electricity. As initial rules were weakened, in particular the additionality principle, the sustainability impact of the new concept was significantly reduced. Nevertheless, green electricity certificate systems and international trade were enabled by its emergence. The article analyses the process of rule formation around green electricity and explains how the nature of green electricity altered as part of that process.