An electric vehicle driven for around 20 miles per day consumes the same amount of energy as an average house over the same period. The grid isn’t designed for the addition of the equivalent of several houses to each substation. Without careful management of when charge is delivered, electric vehicles could cause more problems than they solve.

Publicly available day-time charge points will alleviate demand from the evening rush. However, public trust of electric vehicles will require the availability of a dense, robust charging network, with all charging points compatible with all cars.

The greater charging challenge comes from domestic charging. Smart meters allow utilities an interface into the home, and a potential gateway for electric vehicles to manage charging patterns. Customers will have far greater control over consumption, and tariffs will be offered that favour charging at sensible times. Peak power, the key driver of the necessary grid capacity, will be reduced.

With a dynamic and responsive smart grid forming the backbone of the electric car infrastructure, renewable energies will be better positioned to do much of the recharging, increasing the CO2 reduction benefits of electric cars. Wind, for example, peaks at night, conveniently coinciding with charging vehicles off-peak. Because cars can store energy, it’s possible to match charging regimes to short-term availability forecasts of intermittent forces, and draw the energy from their batteries either to travel or, if not needed, power other domestic appliances or even as a source of electricity for the local grid. The owner could sell surplus energy back to the supplier, smoothing fluctuations between supply and demand.

We need a coordinated effort from policy-makers, scientists, manufacturers and utilities to ensure that smart technology and appropriate business models are in place to support this technology in delivering its full environmental promise.