OSLO, Norway—Electric cars represented almost one in five new vehicles registered in Norway last year, a market share unparallelled anywhere in the world thanks largely to consumer incentives that few countries can match.

Almost 26,000 zero emission cars--all of them electric except for nine hydrogen vehicles--were registered last year in the Scandinavian country, out of a total of 150,700 private new cars, according to the Information Council for Road Traffic.

That took the electric car market share to 17.1 percent, up from 12.5 percent in 2014.

"Norway has an incredibly important role. It is the North Star for what is going on in the rest of the world" in the field, said Christina Bu of the Norwegian Association for Electric Cars.

The Scandinavian country, which ironically enjoys abundant wealth from its North Sea oil and gas reserves, offers numerous incentives to encourage car-buyers to opt for clean vehicles.

While traditional cars are heavily taxed, electric car owners benefit from almost total tax exemptions, making them much more competitively priced.

The electric version of the Volkswagen Golf, the most popular zero emission car sold in Norway last year, retails for 254,000 kroner (26,350 euros, $28,300), much cheaper than the equivalent diesel version sold for 327,000 kroner.

Thanks to the tax breaks, around two-thirds of the electric Golfs made by VW are sold in Norway. The country is also the second-biggest market, behind the United States, for the Tesla S, a US luxury sedan now frequently seen on the streets of Oslo. 

Electric car motorists also enjoy other perks, such as exemptions on road tolls, and, under certain conditions, the use of collective transport lanes and free parking.

Oslo will also shortly open what is likely to be the world's largest electric car parking lot, with 86 recharging stations available at no cost.