NOVELTY - A substrate (410) for holding an array of photovoltaic power cells comprises a core (412) having low coefficient of thermal expansion; a dielectric material having a high product of its bulk thermal conductivity multiplied by its dielectric strength; and power wires (430) on the substrate for electrically connecting the photovoltaic power cells.    USE - For holding array of photovoltaic power cells (claimed) used for solar power generation.    ADVANTAGE - The solar receiver and system for power generation provides capital cost versus output power; provides use of higher solar concentration on a dense array of PV cells, generation of higher output power per solar receiver (scalability), closer unification of PV cells and electrical inverter circuits, manufacturability; provides cooling and packaging for electrical power devices, electrical circuit impedance, low frequency and high frequency electrical properties; provides distinctive high density cooling; and provides distinctive substrates for high voltage, high power density, and very low areal thermal resistivity which pivotally enables generation of high power S-AC from very concentrated sunlight using a very compact solar receiver.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) solar power generation module/receiver comprising substrate; photovoltaic power cells mounted and arranged in an array on the substrate; a cold plate (700) in thermal communication with the photovoltaic cells, where cold plate has fluid paths which provide topologically highly-parallel fluid flow to remove heat from the substrate; and inverter switch connected to the substrate;    (2) solar power generation system comprising photovoltaic power generator delivering power on at least two power output lines; a protective enclosure; at least one grounded connection connected to the protective enclosure and also connected to the power generator; where voltage between two of the power lines exceeds the voltage between each power output line and ground; and    (3) photovoltaic power generation system comprising photovoltaic power cells positioned in a light path from a solar concentrator; a cooling system for removing excess heat from the photovoltaic cells; a sensor which generates a signal correlated with cooling system failure; an optical element that can change the light path; where the optical element comprising shutter in the form of a tracker, mirror, reflector, refractor, lens, prism, scatterer, or absorber; is responsive to the signal.    DESCRIPTION OF DRAWING(S) - The figure shows the principal views of the photovoltaic (PV) Small Cell Modules.    PV cell module (300)    Substrate (410)    Core (412)    Power wires (430)    Power switch (520)    Cold plate (700)