This story is part of a CBC News series entitled In Our Backyard, which looks at the effects climate change is having in Canada, from extreme weather events to how it's reshaping our economy.

The river is running strong and currents are swirling as the 150-metre-long Seaspan Reliant slides gently into place against its steel loading ramp on the shores of B.C.'s silty Fraser River.

The crew hustles to tie up the ship, and then begins offloading dozens of transport trucks that have been brought over from Vancouver Island.

While it looks like many vessels working the B.C. coast, below decks, the ship is very different. The Reliant is a hybrid, partly powered by electricity, the seagoing equivalent of a Toyota Prius.

Down below decks, Sean Puchalski walks past a whirring internal combustion motor that can run on either diesel or natural gas. He opens the door to a gleaming white room full of electrical cables and equipment racks along the walls.

"As with many modes of transportation, we're seeing electrification," said Puchalski, who works with Corvus Energy, a Richmond, B.C. company that builds large battery systems for the marine industry.

In this case, the batteries are recharged by large engines burning natural gas.

"It's definitely the way of the future," said Puchalski.

Corvus's battery systems are specially designed for marine use, and must meet much tougher standards than batteries in automobiles. (Chris Corday/CBC)

The 10-year-old company's battery system is now in use on 200 vessels around the world. Business has spiked recently, driven by the need to reduce emissions.

"When you're building a new vessel, you want it to last for, say, 30 years. You don't want to adopt a technology that's on the margins in terms of obsolescence," said Puchalski. "You want to build it to be future-proof."

Dirty ships

For years, the shipping industry has been criticized for being slow to clean up its act. Most ships use heavy fuel oil, a cheap, viscous form of petroleum that produces immense exhaust. According to the European Commission, shipping currently pumps out about 940 million tonnes of CO2 each year, nearly three per cent of the global total.

That share is expected to climb even higher as other sectors reduce emissions.

New international restrictions on fuels come into effect next year, requiring shipping companies to significantly limit their emissions to comply with the Paris climate agreement. (Chris Corday/CBC)

When it comes to electric ships, Scandinavia is leading the world. Several of the region's car and passenger ferries are completely battery powered — recharged at the dock by relatively clean hydro power.

Below decks, many of the ships are using ever-larger versions of Corvus's battery packs.

How hybrids are working in B.C. waters

After three years of daily use hauling freight along the B.C. coast, Harly Penner, director of fleet engineering and vessel development with Seaspan Marine, has become a big believer in the hybrid technology and its ability to cut CO2 emissions.

"What we're able to do in certain instances is reduce the amount of engines we have running, and when you reduce the amount of engines you have running, you reduce greenhouse gas emissions."

He said it's hard to come up with an exact number, but switching from diesel to a combination of natural gas and electric creates "a substantial" reduction in emissions.

Harly Penner said he sees a bright future for hybrid ferries, but said there are still obstacles when it comes to going fully electric. (Chris Corday/CBC)

But going 100 per cent electric for all vessels on the B.C. coast, including ferries, cruise ships and cargo haulers, wouldn't be easy.

Recharging huge battery packs would require expensive upgrades to the power grid at Canada's ports. Penner said that for Seaspan, which runs a large number of tugboats, ferries and barges, it would be expensive and require a lot of retraining for crews and support staff.

Tougher regulations and retailer pressure

The push for cleaner alternatives is being partly driven by worldwide regulations, with international shipping regulators bringing in tougher emission standards after a decade of talk and study.

Norway already has a number of electric-powered ships, which cut emissions by 95 per cent and are cheaper to operate. (Siemens)

At the same time, pressure is building from customers, such as Mountain Equipment Co-op, which closely tracks its environmental footprint. Kevin Lee, who heads MEC's supply chain, said large companies are realizing they are accountable for their contributions to climate change, from the factory to the retail floor.

"You're hearing more companies build it into their DNA in terms of how they do business, and that's cool to see," said Lee. "It's not just MEC anymore trying to do this, there's a lot more partners out there."

In the global race to cut emissions, all kinds of options are on the table for ships, including giant kites being tested to harvest wind power at sea.

Modern versions of sailing ships are also being examined to haul cargo with minimal fuel consumption.

But in practical terms, hybrids and, in the future, pure electrics are likely to play a larger role in keeping the propellers turning along Canada's coast.