LOS ANGELES (Reuters) - Amazon.com ( AMZN ) on Tuesday will unveil the first of a dozen Volvo electric big rigs it plans to deploy this year to pick up cargo from the nation's busiest container seaport in southern California.

The e-commerce giant said it already has eight of those semi trucks in use at the Los Angeles/Long Beach port complex, where every so-called drayage truck must be zero-emissions by 2035.

The deployment is a first for Amazon ( AMZN ), extending its vehicle electrification projects across its land-based logistics network that stretches from ocean ports to customer doorsteps. The effort is vital to the company's push to reach net-zero carbon emissions by 2040.

So far, a little more than 1% of the 23,761 trucks that serve the Los Angeles/Long Beach port complex are zero-emission vehicles - including 201 electric rigs, Long Beach port spokesman Lee Peterson said.

"Heavy-duty trucking is a particularly difficult area to decarbonize," said Udit Madan, Amazon's ( AMZN ) vice president of worldwide operations.

Amazon ( AMZN ) has rolled out more than 13,500 Rivian electric cargo delivery vans across the country since 2022. The transition to electric semi trucks will be a heavier lift, largely because their bigger batteries require more intensive charging infrastructure.

Amazon ( AMZN ) is still on a learning curve with electric big rigs, said Madan, who oversees Amazon's ( AMZN ) growing logistics network.

The manufacturer of Amazon's ( AMZN ) electric drayage trucks will continue working with the company and JB Hunt, which provides drivers for the rigs, throughout the deployment, said Keith Brandis, vice president of partnerships and system solutions at Volvo Trucks North America.

"We'll still have some lessons learned through this whole process," Brandis said.

Meanwhile, the ports, private companies and truck owners are racing to build heavy-duty chargers to support the transition to zero-emissions vehicles.

In the near term, Amazon's ( AMZN ) electric port trucks will charge at an offsite facility operated by Forum Mobility, a startup that counts Amazon's ( AMZN ) Climate Pledge fund among its early investors. On May 15, Forum Mobility will break ground on a Port of Long Beach depot that promises to deliver high-speed charging for hundreds of drayage trucks each day.