  Smart grids (SGs) promise to deliver dramatic improvements compared to
traditional power grids thanks primarily to the large amount of data being
exchanged and processed within the grid, which enables the grid to be monitored
more accurately and at a much faster pace. The smart meter (SM) is one of the
key devices that enable the SG concept by monitoring a household's electricity
consumption and reporting it to the utility provider (UP), i.e., the entity
that sells energy to customers, or to the distribution system operator (DSO),
i.e., the entity that operates and manages the grid, with high accuracy and at
a much faster pace compared to traditional meters. However, the very
availability of rich and high-frequency household electricity consumption data,
which enables a very efficient power grid management, also opens up
unprecedented challenges on data security and privacy. To counter these
threats, it is necessary to develop techniques that keep SM data private, and,
for this reason, SM privacy has become a very active research area. The aim of
this chapter is to provide an overview of the most significant
privacy-preserving techniques for SM data, highlighting their main benefits and
disadvantages.
