Iberdrola Raises $1.6 Billion in U.S. Green Bond Return

Iberdrola has raised $1.6 billion in a U.S. green bond issuance, its first direct offering in the American debt market since 2009, with proceeds earmarked for electricity network assets including transmission and renewable energy facilities.

The Spanish multinational confirmed that the return opens a new financing channel, allowing the company to expand and diversify its funding sources beyond the Euromarket. Sixteen years is a long absence. The company has decided the wait was sufficient.

How was the deal structured?

The issuance comprised two $800 million tranches:

• A 3-year bond maturing in November 2029, carrying a 5.40% coupon
• A 7-year bond carrying a 5.85% coupon

Iberdrola stated that the final cost was comparable to what it could have obtained in the Euromarket. The pricing, in other words, did not penalize the change of venue.

What drove the demand?

The offering was more than three times oversubscribed, drawing an order book exceeding $5 billion. Iberdrola attributed the strong demand to the green nature of the bonds.

That appetite fits a longer pattern. Iberdrola ranks among the largest corporate issuers of green bonds globally, using the instruments to fund renewable energy, energy efficiency, clean transportation and waste management projects. In 2025, 99% of the financing signed by the company was sustainable, and group sustainable financing exceeded €66 billion by the end of that year.

The company set this trajectory in 2021, when it announced plans for its financing structure to carry an increasingly higher percentage of green and sustainable products. The 99% figure suggests the plan has effectively run its course. There is little room left to green a balance sheet that is already green.

Where will the money go?

Proceeds from the issuance will finance or refinance electricity network assets, mainly transmission and renewable facilities in the United States. Iberdrola said it expects annual investments of $5 billion in the coming years in the country.

That investment rate gives the issuance a clear material logic. A $5 billion annual program requires funding channels that can absorb the load without concentration risk, and a reopened U.S. market provides exactly that. The bond is not an experiment; it is infrastructure finance wearing a green label.

What happens next?

The markers to watch are concrete. The November 2029 maturity will test the 5.40% coupon against prevailing rates, and the $5 billion annual U.S. investment pipeline will determine whether further American issuances follow or whether this was a single repricing exercise.

Iberdrola has framed the deal as the start of a channel rather than a one-off. The market, with $5 billion in orders against $1.6 billion in paper, appears willing to fund that ambition. The next issuance, whenever it arrives, will confirm whether the channel holds.

For now, the number that matters is 99% — the share of Iberdrola's 2025 financing that was sustainable. The U.S. market has just become part of that statistic.