DECADE project proposes a new photoelectrocatalytic (PEC) approach for the conversion of CO2 avoiding water oxidation as anodic reaction to overcome the current limits in PEC system and to maximize effective energy utilization. Novel PEC technology will be developed up to TRL 5 (prototype testing under environmental relevant conditions) using alcohols and waste CO2 as feed. Different applications are investigated: green refinery, distributed green solvent production and use to lower carbon footprint in methanol plant. In the main application, bioethanol and waste CO2 are used to produce a mixture of ethyl acetate (EA) and ethyl formate (EF) in ethanol, to be used as drop-in green solvent or as octane booster fuel component. The net impact is to produce valuable added-value products through an energy-efficient PEC device, to lower the carbon footprint by using waste CO2 and introducing renewable energy in the production chain. DECADE project will develop the PEC concept and validate at prototype unit for distributed production (productivity > 1 g/h of EA and > 1A current density per single 10x10 cm module). Optimization and engineering of electrode/materials and of the PEC design is driven by techno-economic, LCA, market & social assessments. There are several elements of innovation in the proposed DECADE approach, based on the identification of the critical issues in the current PEC design. The project is organized around three main areas: i) advances in materials and technology, with a series of novel concepts and materials proposed (TRL 3 -> 4), ii) upscaling and prototype design & manufacture (TRL 4 -> 5), focused at improving performances, stability and reduce costs, and iii) process validation by using the prototype (TRL 5). Consortium partnership has a strong industrial character, but comprises top level scientists in the area and international collaboration with Japan to allow the best possible benchmarking for the novel approach developed.