This paper gives an overview of the smart grids developments, seen from a power-quality viewpoint; describes the main relations between smart grids and power quality, and goes into some detail for some of the aspects. Different types of real and virtual energy storage are distinguished. Power-quality monitoring in the smart grid is discussed in detail. Further aspects discussed in the paper are: emission by new devices; interference between devices and power-line communication; allocation of emission limits; improving voltage quality; immunity of devices; and weakening of the transmission grid. Although the smart grid brings many new power-quality challenges, these should not result in the introduction of unnecessary barriers against the introduction of new technology.