We present a set of calorimetric data obtained with Fleischmann-Pons type cells, working in a novel electrostatic configuration aimed at achieving high deuterium loading. The analysis of such data, which includes an eight day run with a "blank" cell (Pt cathode), shows that : (a) the heat dissipation of the cells depends strongly on the physical processes occurring at the cathode; (b) the continuing calibration with periodic heat pulses yields accurate estimates of the excess enthalpies generated in the cells; (c) very high excess power densities are observed in the cells electrolyzing D2O with Pd cathodes.