When it comes to states friendly to electric cars, Washington is pretty close to the top.

It has one of the highest percentages of registered plug-in electric cars in the country, according to the U.S. Energy Information Administration.

Electric cars get a sales-tax exemption in Washington, and access to charging infrastructure that's fed mostly from wind and hydro power.

DON'T MISS: Washington State To Give Electric Cars Tax Breaks, Carpool-Lane Access? (Dec 2014)

Yet Washington buyers are stuck with the same limited selection of models as in states with far less generous policies or eager buyers.

Certain models of battery-electric car--including the BMW i3, Ford Focus Electric, Mitsubishi i-MiEV, Nissan Leaf, and Tesla Model S--are available in Washington.

But many other low-volume models, from the Chevrolet Spark EV to the Volkswagen e-Golf, aren't.

2014 Fiat 500e

2014 Fiat 500e

What gives?

As it turns out, while Washington adopted California's emissions standard, it failed to include that state's zero-emission vehicle mandate.

That means there's no incentive for manufacturers to sell more electric cars in Washington state, explains a recent Seattle Times blog post.

RELATED: Compliance Car Update: Which Electric Cars Are Loss Leaders? (Mar 2014)

The mandate requires carmakers to sell a certain percentage of zero-emission vehicles in California.

That led to those manufacturers developing low-volume models specifically for the purpose of meeting that state's mandate.

These "compliance cars" include the Spark EV, Fiat 500e, and the recently-discontinued Honda Fit EV and Toyota RAV4 EV, among others.

2015 Volkswagen e-Golf Limited Edition

2015 Volkswagen e-Golf Limited Edition

Washington doesn't get these cars, nor does it get certain low-volume models like the Mercedes-Benz B-Class Electric Drive and Volkswagen e-Golf.

And without regulatory strong-arming, many carmakers don't want to invest in expanded distribution of electric cars.

MORE: Kia Soul EV To Go On Sale In Five More States By This June

They often want to limit the money they spend to develop an electric model that is only intended to sell in small numbers, and restrict distribution to states where sales count toward the requirements of the ZEV mandate.

"I hope you don't buy it," Fiat Chrysler Automobiles CEO Sergio Marchionne infamously said of the 500e, "every time I sell one it costs me $14,000."

2015 Kia Soul EV

2015 Kia Soul EV

The Fiat and the Chevy Spark EV are both available in neighboring Oregon, and some Washington residents have reportedly crossed the border to buy examples of those models.

However, local servicing can be difficult, as dealers that don't sell the electric variants lack the equipment and training to work on them.

Washington buyers will get at least one more electric-car option in a few months, though.

The state is one of five that will get the Kia Soul EV, beginning in June.

The Soul EV is currently sold only in California, but Kia decided to expand to Washington, Georgia, Texas, Oregon, and Hawaii in response to strong consumer interest.

[hat tip: Brian Henderson]

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