Methods, systems, and apparatus for plating a metal onto a work piece are described. In one aspect, an apparatus includes a plating chamber, a substrate holder, an anode chamber housing an anode, and an ionically resistive ionically permeable element positioned between a substrate and the anode chamber during electroplating. The anode chamber may be movable with respect to the ionically resistive ionically permeable element to vary a distance between the anode chamber and the ionically resistive ionically permeable element during electroplating. The anode chamber may include an insulating shield oriented between the anode and the ionically resistive ionically permeable element, with opening in a central region of the insulating shield.