Department for Transport data shows 1,799 ultra-low emission vehicles (ULEVs) were licensed to addresses in the area as of September – a 62% increase from 1,108 a year earlier.
Of those, 317 (18%) were registered to companies in the area, while 1,482 were privately owned.
Of the new ULEVs registered, 1,103 were battery powered – defined as zero emission – and 663 were plug-in hybrid electric models, combining electric and fossil fuel power.
The new vehicles were among 83,000 registered nationally – 15% of all new registrations between July and September last year and bringing the number of ULEVs on the roads to 645,000 – up from 373,000 the year before.
The Government has committed to ending the sale of new petrol and diesel cars and vans by 2030, and ensuring all new sales are "zero emissions at the tailpipe" by 2035.
But Caroline Russell, the Green Party's spokeswoman for transport and healthy streets, said more must be done to provide a better network of charging points.
She added that it would also be a mistake to rely on electric vehicles to resolve the climate and air pollution crisis, saying: "It doesn't matter how cars are powered, they still contribute to traffic deaths, congestion and dangerous air pollution from tyre wear."