Despite hefty incentives, electric vehicle sales have remained stagnant in the United Kingdom. While sales doubled in 2013 compared to 2012, matching the global trend, just 2,500 vehicles found homes last year. That’s less than the Nissan Leaf sells in some single months in the U.S. The U.K. government has this week promised to invest £500 million (almost $850 million) to boost the ‘ultra low emission vehicle’ industry.