Recasts and writes through

By Melanie Burton

MELBOURNE, May 1 (Reuters) - Aluminium producer Alcoa AA.N said on Thursday its order book for the second quarter remains robust and it has yet to see a drop in orders related to U.S. tariffs, while also noting that this week's power outage in Spain posed risks to its business there.

Since taking office, U.S. President Donald Trump has imposed a flat 25% tariff on aluminum imports "without exceptions or exemptions" in a bid to lift U.S. production of the metal.

"Our first quarter order book was strong. Our second quarter order book remains strong. So we have yet to see a fall off in orders associated with the tariffs," CEO William Oplinger said at a mining event in Melbourne.

"When we're talking to our customers, they're uncertain about the future. So we just don't have good insight much past the first half now."

Alcoa said at its first-quarter earnings call last month that it expects U.S. tariffs on aluminium imports from Canada to cost the company about $90 million in the second quarter.

Oplinger said Alcoa supported Trump's vision of a competitive manufacturing environment in the U.S. and the best way to achieve that would be to make sure Canadian aluminium gets to the United States.

The U.S. is about 4 million tonnes short of aluminium each year and lacks economic deposits of the raw material, bauxite to produce aluminium, he added.

Alcoa does not have any immediate plans to build any smelters in the U.S. which typically take 5-7 years.

It would take seven new U.S. aluminium smelters to produce the 4 million tonnes, costing an estimated $35 billion, he said. Alcoa, the largest aluminium producer in the U.S., has a market value of $6.5 billion, he pointed out.

"So this concept of creating manufacturing in the near term is simply not going to happen in primary aluminum."

The as-yet-unexplained power outage that rocked Spain and Portugal this week has raised the risks for Alcoa's San Ciprián aluminium complex in Spain, Oplinger said.

"At this point, we don't yet have an answer to what happened to the energy in Spain, and in my view, we will take some days to evaluate the risks associated with further losses of power," he said.

"If the grid doesn't understand what happened, it is very difficult to have an electro-intensive business in a place that can't guarantee that the electricity will stay on."

Alcoa is conducting a review to assess damage at the plant. Oplinger said the facility's smelter was in the process of restarting, which was 8-10% complete.

Production at the plant was curtailed in 2021 due to high power prices and it has been in the process of being restarted with a full ramp-up expected by October.

(Reporting by Melanie Burton in Melbourne and Renju Jose in Sydney; Editing by Edwina Gibbs)

((renju.jose@thomsonreuters.com;))