Electrical current generated by a photovoltaic cell (PVC) was supplied to wastewater in a mechanically mixed and sealed reactor using stainless steel electrodes Hydrogen gas was generated by reaction of protons released from decomposition of organic compounds and electrons provided by electrical current Gas phase was composed of 75-99% H(2) gas Hydrogen gas produced from electrolysis of water (9 5 L) was only 12 5% of that produced from wastewater (75 L) within 432 h TOC content of wastewater was reduced from 4800 to 4200 mg L(-1) with nearly 12 5% TOC removal Fermentative hydrogen gas production from wastewater was negligible in the absence PVC power Wastewater inoculated with anaerobic sludge generated higher hydrogen gas volumes as compared to wastewater with the application of solar power Energy conversion efficiency for hydrogen production by electrohydrolysis of waste compounds (hydrogen energy/electric energy) was found to be 92% for the wastewater containing anaerobic sludge (C) 2010 Professor T Nejat Veziroglu Published by Elsevier Ltd All rights reserved