As an energy source to replace petrol and Diesel engines in cars electricity will only work to its maximum when the electricity generated is as ‘green’ as can be. That will require a continued huge investment in green electricity through solar, wind and hydro electricity including tides and currents. It’s too easy for doubters to point at fossil fuel electricity generation and say that EVs still pollute. It worth pointing out that even the inefficient hybrids have their plus points, if used thoughtfully they can significant reduce the harmful gasses from motor vehicles in towns and cities. Investment in green electricity will also be needed if hydrogen engines are going to become a realistic option as a lot of electricity will be needed to produce the clean fuel. Hydrogen cars emit water vapour, that might ‘only’ be water but it’s also a greenhouse gas.