The present work reports a novel device that generates energy simply by water splitting and requires no other external energy source. Generating green energy by hydroelectric cell (HEC) from water splitting is an emerging concept in the field of energy harvesting. Efficient non-photocatalytic splitting of water molecules at room temperature produces green electricity even without sunlight. The synthesized pure and lithium (Li) substituted nickel oxide (NiO) is an oxygen deficient mesoporous material and is reported for the first time for this application. Using an electrolytic chain reaction, the reported material dissociates water into H3O+ and OH- ions, generating a potential across electrodes. The tuned ratio of 80% nickel and 20% lithium (Li20Ni80O) based HEC produced 135 mA at 1.06 volts using a pellet radius of 1.75 cm. This provides a significant peak power (Pout) of 143 mW. The material is characterized using X-ray spectroscopy and Electron Paramagnetic Resonance spectroscopy for oxygen vacancies. Photoluminescence (PL) confirms the defect states formed by Ni2+ interstitials. Mesoporosity and surface areas are observed by Brunauer Emmett Teller (BET). The ionic diffusion due to splitting of H3O+ and OH- ions is observed with Nyquist curves. Nickel oxide is a cost-effective and ecologically sustainable solution for green energy generation. The energy generated per square meter by this method is comparable to solar cell energy with the added advantage of generating energy in the dark as well. Since, byproduct of this process is the generation of hydrogen gas, this material can also be used for hydrogen production. This technology may lead to an alternative route in the power sector.