Tougher seismic standard raises concerns

CHILE: A proposal to tighten up building standards in Chile in the wake of a massive earthquake could force manufacturers to produce specially strengthened components for the country's growing wind-energy industry, making the sector less competitive.

The new building standards for industrial plants were proposed following recent earthquakes in Chile (Walter Mooney/US Geological Survey)
The new building standards for industrial plants were proposed following recent earthquakes in Chile (Walter Mooney/US Geological Survey)

In March, the government sent a draft version of the updated NCh2369 standard for seismic resistivity in industrial plants to the Chilean standards institute INN.

The document will now be put out for a 60-day public consultation, during which companies and individuals will be able to raise questions and concerns.

"What is worrying for the moment is that we have only seen a draft document, so there is no certainty about the requirements," said Chile’s renewable energy association, Acera.

As befits one of the world’s most seismic countries, Chile’s earthquake-resistant building standards are considered among the best in the world. And the standards are being largely adhered to.

When the fourth-strongest earthquake on record hit the country in February 2010, just one new building collapsed and only 4% suffered serious damage. As a result, the number of dead was measured in hundreds rather than tens of thousands.

The document will update the original standard, which was one of the first in the world for industrial plants when published in 2003.

Specialist infrastructure

However, over the years, engineers have found that the requirements could be sharpened, especially with regards to specialist infrastructure, such as ports and power plants, according to Sergio Contreras, a structural engineer who helped lead the committee that drew up the revised standard.

The updated standard includes a whole chapter dedicated to power plants.

But some fear the new standards could be too demanding for wind turbines and affect the competitiveness of the technology.

A spokesman for turbine maker Siemens Gamesa (SGRE) said the new standards represent a turning point in terms of the design philosophy of wind farms.

"This philosophy implies that any wind turbine can withstand a seismic event and the operation will not be affected," he said.

To meet the standards would imply changes to the standard manufacturing process for turbines and their components. In some cases the design may have to be altered based on the seismic exposure of each site.

Proven record

So far, the country’s wind farms have proved notably resistant to seismic movements. Foundations designed to support towers against the blustery conditions that have made Chile one of the hottest markets for wind energy this decade can usually withstand all but the strongest seismic movements.

There is currently 558MW of wind capacity under construction in Chile, with environmental licences granted for another 9.2GW.

When an earthquake measuring 8.3 on the Richter scale struck the northern region of Coquimbo — the heart of the country’s wind industry — in September 2015, no wind turbines suffered significant damage, helping power supplies to be rapidly restored.

Requiring manufacturers to provide specially-reinforced components or even a specific design for wind turbines to comply with Chile’s tougher standards could mean significant cost increases, making wind energy less competitive in the country, the SGRE spokesman warned.

But others are less concerned. Rather than updating standards, the new standard will bring together information contained in existing documents, said Daniel Llanos, engineering manager at developer Mainstream Renewable Power.

Even playing field

The same tough standards will also apply to other generation technologies, so any cost increase would be across the board. Meanwhile, the trend towards larger and taller turbines is requiring the industry to update its existing standards anyway, Llanos said.

Similar standards are being required across the Pacific Rim, where seismic and volcanic activity is common.

"Having a clear standard for renewable-energy projects will mean these are an increasingly safe, reliable and efficient alternative," Llanos added.

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