Clean air. It’s the one cause that developmental directives and energy policies draw their breath from. The immediate reason why governments are planning to curb the sale of petrol and diesel fuelled cars sooner than later. It is the most compelling out of many reasons to switch to a pure electric or hybrid powertrain—other reasons include the need for renewable energy, the sustainable use of power, long-term cost-effectiveness and a desire to tread the earth lightly. And this clean air requires clean energy, which is largely electrical at the receiving end, although the original source (such as solar, wind or natural gas) is still an essential factor that needs to be taken into consideration.