Earlier this week Dutch energy consulting and certification company KEMA announced that the Hoogkerk "PowerMatching City" had been officially opened by the mayor of Groningen. According to KEMA:

Hoogkerk is the first microgrid project in Europe to integrate a full-scale, operational “smart” residential community energy system. The community includes 25 interconnected residential homes equipped with micro-cogeneration units, hybrid heat pumps, PV solar panels, smart appliances and electric vehicles, and additional community-based power produced by a wind farm and a gas turbine.

Whilst 25 homes seems to me to be stretching the definition of "a city" a bit far, it seems that:

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