Image copyright Terje Erstad Image caption Trond Bonesmo welcomes Norway's new low-carbon electric ferries

It might be slow, but the romance of commuting by ferry is not lost on Trond Bonesmo as he boards MF Norangsfjord for the crossing from Magerholm to Sykkylven.

"It's a welcome break, and the view isn't too bad either," he says as he looks across the sea towards the Sunnmoere Alps' snow-covered peaks.

"A bridge across the fjord would obviously make the crossing faster, but Storfjorden is two or three kilometres wide and 700 metres deep, which makes it very expensive to build one," says Mr Bonesmo, IT and operations manager for a consumer goods company.

Many Norwegian fjords present similar difficulties to bridge builders, so instead the country's coastal population relies on ferries that link their often remote communities.

Each year, some 20 million cars, vans and trucks cross the country's many fjords on roughly 130 ferry routes.

Most of Norway's ferries run on diesel, spewing out noxious fumes and CO2.

But this is about to change.

Image copyright Getty Images Image caption Building bridges across Norway's mountain-flanked fjords would be difficult and costly

Following two years of trials of the world's first electric car ferry, named Ampere, ferry operators are busy making the transition from diesel to comply with new government requirements for all new ferry licensees to deliver zero- or low-emission alternatives.

"We continue the work with low-emission ferries because we believe it will benefit the climate, Norwegian industry and Norwegian jobs," Prime Minister Erna Solberg said in a speech in April 2016, in which she vowed to help fund required quayside infrastructure.

Ferry company Fjord1, which operates the MF Norangsfjord, has ordered three fully electric ferries that are scheduled to enter active service on some of its routes in January 2018.

Multi Maritime, which designed the ferries, welcomes the growth in demand.

"Several years of investment in sustainable technologies have resulted in us having more than 10 fully electric and plug-in hybrid ferries under construction by several yards," says Gjermund Johannessen, managing director.

Image copyright Multi Maritime Image caption Multi Maritime has designed three electric ferries for Fjord1

In addition to new-builds, the marine division of Siemens, which developed the technology for Ampere, believes 84 ferries are ripe for conversion to electric power. And 43 ferries on longer routes would benefit from conversion to hybrids that use diesel engines to charge their batteries.

If this were done, nitrogen oxide (NOx) emissions would be cut by 8,000 tonnes per year and CO2 emissions by 300,000 tonnes per year, equivalent to the annual emissions from 150,000 cars, according to a report penned jointly by Siemens and the environmental campaign group, Bellona.

Long-distance ferries are not well suited to electrification, but about 70% of Norway's ferries cover relatively short crossings, so switching to electric power would pay for itself in a few years, according to the report.

Each ferry would save about a million litres of diesel per year, helping to reduce energy costs by 60% or more, says Odd Moen, head of sales at Siemens' marine division.

"The electricity to power Ampere, with its 360 passengers and 120 cars, across a six kilometre-wide fjord costs about 50 kroner (£4.65; $5.80)," he says.

"In Norway, that won't even pay for a cup of coffee and a waffle."

Image copyright Fosen Namsos Image caption Norway's older ferries are also being converted from diesel to electric

Ampere's electric powertrain, which was designed by Fjellstrand shipyard using Siemens technology, includes an 800kWh battery pack weighing in at a hefty 11 tonnes, which powers two electric motors, one either side of the vessel.

The batteries are fully charged overnight, but as each of the 34 daily 20-minute crossings of the Sognefjorden requires 150kWh, the battery must be topped up during loading and unloading as well.

During initial trials, the fast charging placed excessive strain on the local grid, designed as it was to service a relatively small population.

To lighten the load, high-capacity batteries were put on constant charge on either side of the fjord, ready to transfer the electricity quickly to the ferry's batteries whilst docked.

The charging added an extra burden to the Ampere crew's busy schedules. But this challenge is being dealt with by the latest electric ferry designs, which incorporate fully automatic charging systems.

Emissions from diesel-powered ferries have always been a problem.

"When they're docked, their engines are idling - that's when you see those black fumes coming out of their chimneys - and then they're accelerating hard away from land, so their engines are never operating with maximum efficiency," explains Mr Moen.

Image copyright Getty Images Image caption Ferry pollution is an issue for most busy city ports; Hong Kong is no exception

Mr Moen says he has registered much interest in the technology from overseas, and urges other governments to require and support a switch from diesel to electric ferries where appropriate.

Indeed, emissions from ferries is a problem not just in Norway, but in coastal communities and cities all over the world.

This is why Scotland has been moving to lower-carbon hybrid ferries - combining diesel and lithium-ion batteries - with three ferries now in operation.

In Hong Kong, the Environmental Protection Department has long been waging a war on emissions from ferries that are responsible for much of Victoria Harbour's poor air quality.

Similarly, in New Zealand a single ferry visit to Wellington used to pollute the air as much as all Wellington's cars did in a month, according to National Institute of Water and Atmospheric Research figures.

Back in rural Sykkylven, where the air is relatively fresh, NOx emissions pose less of a problem than in a congested city.

But CO2 emissions from ferries should be curbed nevertheless to help combat climate change, Mr Bonesmo says, as he steers his electric car off the ferry.

By 2020, an all-electric solution will have replaced the current diesel-electric ferry on the Magerholm-Sykkylven crossing.

"And then my entire commute will be emissions free," Mr Bonesmo grins.

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