The Day the Lights Went Out

The Iberian blackout of April 28 2025 does not have a single villain.

This overview neutrally explains what happened and what the remedies are. The lazy explanations you may have heard of - renewables, negative prices, a cyber attack, or just add batteries - just don't survive contact with the evidence.

What could investors do to insulate themselves against similar events? And how might sustainable investors develop the theme into something investible?

Infrastructure investors should check how assets behave when the grid is under stress, not only whether they are documented as compliant.

The next phase of electrification depends on unglamorous system-support services - including testing, commissioning, monitoring and stability services - as much as headline generation.

For sustainability-led investors, the better test is not simply whether an asset being considered is green, but whether it helps make a greener system dependable. Do not conflate diversification with resilience.

A longer version of this paper, available on request, goes into detail on both questions.