Global warming and water/soil pollution are among the most urgent issues for the Earth, that involve both C and N cycles, and which need to be addressed employing innovative technological solutions. Therefore, it is necessary to develop renewable energy-driven technologies that can intervene in these cycles to make them sustainable. In this framework, CRONUS project aims at introducing a disruptive technology based on solar energy powered coelectrolysis of CO2 and nitrate (NO3 −) to produce urea, largely supporting the circular economy in sectors like agrifood and chemical industry and avoiding the use of critical raw materials. A flue gas containing CO2 from an industrial plant, e.g. a fertilizer industry, is used as CO2 source, while wastewater containing nitrate compounds e.g. from the agriculture activity, to be used as NO3 - source. These wastes are co-reduced to urea employing innovative and specifically designed electrocatalysts. In order to add value to the whole process, urea production at the cathode is coupled with the selective electrochemical oxidation of lignin and of its derivatives into useful chemicals (e.g. vanillin) at the anodic, thus valorizing at the same time also a waste generated by the agrifood industry (i.e. lignocellulose). The two processes are employed in a newly designed flow electrolyzer, which after optimization is able to produce urea and vanillin at industrially relevant scales. Solar energy, through the use of a device-integrated photovoltaic panel, is used as input to power the process, thus demonstrating the feasibility of a renewable energy-driven technology.