Solid-state nanopores have shown great potential in investigating salinity gradient energy generation as a renewable power generator. In this work, various diameter silicon nitride (Si₃N nanopores were fabricated to investigate the power generation between two potassium chloride solutions with different concentration gradient ratios by reverse electrodialysis. The maximal estimated power density of a Si₃N₄ nanopore measured experimentally can be high to 16649Wm. To compare with the single Si₃N₄ nanopore, multiple nanopores array has also been investigated. The equivalent circuit model of multiple Si₃N₄ nanopores array generator is quantitatively constructed by massive reproducible experimental data and theoretical derivation. For nanopore array, the osmotic current basically keep a linear growth with the number of the nanopores at every concentration ratio. While, the osmotic voltage is basically independent on the number of nanopore. The power generation circuit of the nanopore array can be regarded as a parallel circuit of multiple nanopores. Power generation from concentration gradients in Si₃N₄ nanopores could be widely used in a variety of applications like ultra-low power devices and micro-nano electromechanical systems.