By Laila Kearney

Jan 14 (Reuters) - Connecting to the U.S. electrical transmission system has become the biggest problem for powering up Google data centers on the ​grid, as the wait times to connect surge to more than a decade ‌in some parts of the country, an energy executive with Google said on Wednesday.

The world's largest technology companies ‌are running up against the realities of the country's slow-moving power system as they race to access vast amounts of electricity for the expansion of energy-intensive data centers, which are increasingly being used to train and roll out artificial intelligence.

"Transmission barriers are the number one challenge we're ⁠seeing on the grid," Marsden ‌Hanna, Global Head of Sustainability and Climate Policy at Google, said at an event held by the American Enterprise Institute.

"We had one utility ‍who told us 12 years to study the interconnection timeline, which is sort of wild, but that's what we're seeing," Hanna said.

In order to address the wait times, Hanna said the country needs ​to address permitting delays for new transmission, and utilities should deploy technologies that can ‌increase power flows from the existing system, along with other actions.

Google is looking into arrangements, known as co-location, that might help the company circumvent some of the wait times by locating some data centers directly next to power plants. Colocated arrangements can involve bypassing the transmission system altogether and the long wait times associated with connecting to it.

"That's the strategy we're ⁠pursuing with colocation and our hope is that ​these can eventually be grid-connected resources," Hanna said. Generally, ​Hanna said, Google's preference is to connect to the grid.

Colocation is a complex and controversial topic, which has raised concerns about who pays for ‍costs associated with the ⁠arrangements and what it means when power from an existing power plant is diverted for a single customer.

The issue of co-location is being taken up by federal ⁠and regional regulators, who are seeking to set guidelines around the costs and reliability questions raised by the ‌prospect of building data centers next to existing power plants.

(Reporting by Laila ‌Kearney in New York; Editing by Stephen Coates)