Attaching appliances to a power socket via a smart plug containing sensors and a ZigBee transceiver allows information about the appliances' power consumption to be beamed automatically to a broadband router within the home, and thence to a web server located elsewhere.

ECONOMIST: The much-talked-of smart grid prepares to enter the home

Using a dedicated high-current electric circuit, like those installed for electric ovens, these can recharge the MINI E in 4.5 hours. (With an ordinary mains socket, by contrast, recharging could take all day.) For cars with smaller battery packs, like the Smart, overnight recharging from a conventional socket is possible.

ECONOMIST: Rational consumer