Sustainable & Clean Power Procurement6 / 12
Renewable Energy Guarantees of Origin (REGOs)
Buying green certificates to offset grid consumption; additionality debate.
10 min read · Jacob Willis, Net Zero Lead · Last reviewed July 2026
Renewable energy certificates let organisations claim the use of renewable electricity, but their credibility varies enormously. Understanding certificates - what they prove and what they do not - is essential to making honest clean-energy claims and avoiding greenwashing.
In this lesson
- 01What certificates are
- 02Green tariffs
- 03The credibility problem
- 04Unbundled certificates and their critics
- 05A hierarchy of credibility
- 06Making honest claims
- 07Certificates in context
- 08Sources and further reading