Your Green Energy Certificates Aren't Reducing Your Emissions

Published by the Verdani Institute for the Built Environment (VIBE)

Renewable Energy Certificates (RECs) have become one of the most widely used tools in corporate sustainability reporting. Purchase enough of them, and on paper your buildings run on 100% clean energy. Your sustainability report looks strong. Your GRESB score gets a boost. Stakeholders see a commitment to renewable power. There is just one problem: according to VIBE's guidance report, Pathways to Portfolio-Level Decarbonization, RECs do not reduce your buildings' actual energy consumption or carbon emissions by a single kilowatt-hour.

This is not a fringe critique. It is a growing consensus among the sustainability leaders interviewed for the report, and it represents one of the most important strategic distinctions a real estate organization can make as decarbonization expectations intensify.

What RECs Actually Do and Don't Do

A REC represents the environmental attributes of one megawatt-hour of electricity generated from a renewable source. When you purchase a REC, you are buying a certificate, not the electrons themselves. Your building continues to draw power from the same grid, generated by the same mix of sources, as it did before. The renewable energy you are claiming credit for may have been generated hundreds of miles away, sold into a different grid, and consumed by someone else entirely.

For organizations with genuine net zero commitments, and increasingly, for those facing mandatory building performance standards like New York's Local Law 97, this distinction matters enormously. A building that relies primarily on REC purchases to meet its sustainability targets is accumulating compliance and reputational risk. As disclosure standards tighten and scrutiny of greenwashing intensifies, the gap between claimed and actual emissions performance becomes harder to defend.

The Reduce-First Imperative

The report is unambiguous on sequencing: reduce actual energy consumption first, then address remaining emissions through legitimate means. RECs and carbon offsets have a role to play at the end of a credible decarbonization strategy — covering residual emissions that cannot yet be eliminated — not as a substitute for the hard work of efficiency, electrification, and onsite renewable generation.

Organizations that have built their net zero claims primarily on REC purchases face a significant reckoning as the market, regulators, and investors develop more sophisticated expectations. Those that have invested in actual building performance — measurable, verifiable reductions in energy use and carbon output — are building claims that will hold up under scrutiny for years to come.

The question worth asking of any sustainability strategy is a simple one: if we removed our REC purchases tomorrow, what would our actual emissions performance look like? The answer tells you everything about where the real work remains to be done.

Download VIBE's full guidance report, Pathways to Portfolio-Level Decarbonization, free at verdani-institute.org. Subscribe to the VIBE newsletter for updates on our upcoming Resilience Strategies report, publishing in 2026.