Now

Today, the goods movement system runs on diesel, which is just another form of petroleum. Ships burn bunker fuel, the dirtiest diesel around, as they carry massive containers (full of almost every type of goods you can imagine, from iPods to engine parts, from shoes to shin-guards). Cargo handling equipment (CHE) – the yard tractors, cranes and other big machines that move containers around a port, before they are loaded onto trucks or rail – run on diesel. So do the heavy-duty trucks and trains that carry containers to their final destinations across the country.

Unlike other fuels, diesel emissions have been found by the California Air Resources Board to be a toxic (carcinogenic) air contaminant. Diesel has significantly higher carbon content than alternatives. And even the newest diesel-fueled heavy-duty truck engines – the so-called “clean diesel” engines running on the Ultra Low Sulfur Diesel (ULSD) being sold in California – still have significantly higher NOx emissions.

Overall, electricity and natural gas are the cleanest alt-fuel options available today for mass deployment in port applications to displace diesel. Both can be far cleaner than diesel – in terms of smog-forming  NOx emissions, toxic diesel particulate matter, and greenhouse gases – but both are not available for every application. And the magnitude of their emissions advantages over diesel can depend on the source of the alt-fuel. (See below.)

For heavy-duty trucks and yard tractors (cargo handling equipment), natural gas is the cleanest available fuel. It has a lower carbon intensity than diesel, is not toxic, and has significantly lower emissions of smog-forming NOx (33%-50% lower). The only heavy-duty truck to meet 2010 EPA standards is fueled by natural gas. The cleanest long-haul heavy-duty truck, which exceeds 2007 EPA standards, is natural gas. (That’s why environmental and public health groups overwhelmingly support natural gas-fueled heavy-duty equipment over diesel.)

Trucks running on electricity are not yet technologically viable.

For cold-ironing (or shoreside power) – providing ships with an alternative, shore-based power source while they’re in harbor unloading, loading or waiting for a berth – electricity is an option, where you can retrofit terminals and ships so that they can connect to the existing electric grid. Another option is natural gas, which can fuel mobile generators that power the ship, allowing it to shut down its own, bunker-fuel-burning engines.

In both cases, the source of the “fuel” is relevant to how “clean” it is. Grid-based shoreside power is ideal, if its electricity comes from renewable generation (e.g., wind or solar). If, on the other hand, the electricity is generated by coal-fired plants, then the pollution – local pollution as well as greenhouse gas pollution – has simply been moved from one location (the ship’s engines at the port) to another location (the electricity generation facility). Similarly, if your natural gas arrives via overseas shipments as LNG (liquefied natural gas) – as opposed to North American natural gas that arrives via pipelines, before being used to fuel LNG or CNG vehicles – then its carbon footprint is higher. (Regardless, it’s still cleaner than diesel.)

Trains are powered by diesel, and their engines have not been subject to the level of emission-reduction requirements imposed on truck engines. Nonetheless, because moving containers via train is generally more efficient than via truck, increasing rail use tends to decrease overall emissions.

Biofuels are being tested in some port environments for trucks and other equipment, but thus far have been hamstrung by high NOx emissions.

NextGen

For heavy-duty trucks, the diesel industry promises that its engines will meet 2010 EPA standards, which require them to bring NOx emissions levels down to one-sixtieth (1/60th) of the 2007 EPA “transitional” standards that some diesel engines have just met. Even if they do – and prior regulations have been rolled back in the past when the industry failed to meet them – diesel will still be oil, and it will still have a relatively high carbon intensity.

Long-haul heavy-duty natural gas trucks will have to join their short-haul cousin in meeting 2010 EPA standards.

An electric battery truck is currently being tested. It could become viable as a zero-emission alternative for the shortest drayage runs.

For grid-connected cold ironing, the primary fuel challenges are simple:  How much of the electricity will be generated by coal (worst), by natural gas (better), and by renewables (best)? And does the grid have the capacity to handle the added load of containers ships?

For mobile shoreside power generators, the next-generation challenge will be further reducing emissions.

Finally, we need to develop trains running on cleaner fuels and technologies. Even if rail is generally more efficient at moving cargo – moving more containers with less energy – train engines have successfully avoided clean up (and regulation requiring it) for far too long. As a result, cleaner train fuels and technologies could produce dramatic emissions reductions. Electric trains, for instance, are already in use for passenger service around the world.

Vision 2050

And, of course, the lion’s share of containers should be moving on zero-emission rail systems.