Monopole rectenna arrays distributed over a curved surface for multi-directional, multi-polarization, and multi-band ambient RF energy harvesting in accordance with embodiments of the invention are disclosed. In one embodiment, a rectenna array includes a curved grounding surface, a plurality of multi-band antennas distributed across the surface of the curved grounding surface and configured to harvest RF energy in multiple spectral bands, from multiple directions, and with multiple polarizations, a multi-band rectifier connected to an output of each of the plurality of multi-band antennas, and a direct current (DC) combiner including a plurality of inputs connected to outputs of the multi-band rectifiers and an output configured to provide DC power to a load.