  Increased distributed Photo-Voltaic (PV) generation leads to an increase in
voltages and unwarranted backflows into the grid. This paper investigates
Demand Response (DR) with Electric Water Heaters (EWHs) as a way to increase
the PV hosting capacity of a low-voltage feeder. A control strategy relying
only on power measurements at the transformer is proposed. Flexible loads are
optimally dispatched considering energy acquisition costs, a PV shedding
penalty, and power and energy constraints. Furthermore, grouping of loads and
PV plants is investigated, and switching penalties are used to reduce the
unnecessary switching of loads. It is shown that this strategy can
substantially increase the PV hosting capacity of a Low-Voltage (LV) feeder,
even when only basic controllability is available.
