Siemens started testing its "eHighway of the Future" concept in Germany back in 2012, with commercial vehicles retrofitted with a diesel/electric powertrain drawing electricity from overhead cables to zip along on electric motor power only. Public highway trials in Sweden followed, and now the US has joined the party with a mile-long demo near the ports of Los Angeles and Long Beach.
The aim of the Californian demonstration is to show that the Siemens system will work on public roads in an urban environment, while also substantially reducing smog-forming, toxic emissions around ports.
"This project will help us evaluate the feasibility of a zero-emission cargo movement system using overhead catenary wires," said South Coast Air Quality Management District's Wayne Nastri. "This demonstration could lead to the deployment of eHighway systems that will reduce pollution and benefit public health for residents living near the ports."
For this first US eHighway demo, three big rigs will be supplied with electric power by an overhead catenary system on both north and south-bound lanes of the mile-long route in Carson, California, similar to those used to power street trolleys around the world. The small test fleet is made up of a battery-electric truck, a compressed natural gas/electric hybrid and a diesel/electric big rig, but the eHighway is not restricted to just test vehicles – other freight haulers can share the road, too.
As with previous trials, the test vehicles feature a pantograph up top that's raised to meet the contact line above, which powers the electric motors in the trucks' hybrid powertrains. The pantograph can raise itself when onboard sensors detect the overhead lines, and lower again when the truck gets to the end of the line. If the driver needs to pull out and overtake, the batteries, natural gas or diesel systems kick in until the truck moves back under the catenary lines.
"Experts expect global CO2 emissions from road freight traffic to more than double by 2050," warned Andreas Thon of Turnkey Projects & Electrification, North America. "This electrified truck system, what we call eHighway, can modernize the existing infrastructure using the latest technology to accommodate the growing amount of freight travel, reduce harmful emissions, and keep these ports, one of our country's major economic drivers, competitive."
Three more field trials are due to start in Germany in 2019.
Source: Siemens
True, as far as it goes, but read above for reasons why CO2, CH4 etc have the greater effect over time. We cannot control water vapor in the atmosphere except by warming the air so that higher levels can arise before condensation & cloud formation. The water cycle is intensified by other greenhouse gases. Which "top notch scientists" are you referring to?