White light sources based on Inorganic LED is an emerging technology which will dominate the lighting market. There remain significant research challenges before a high efficacy, high lumen output, retrofit lamp with high quality white light can be made at an affordable price. In mainstream LED lighting, white light is obtained from a phosphor layer which is placed on top of a blue light-emitting LED. OPERA will place the LEDs in a highly-reflective light-mixing chamber with the phosphor at the exit surface, reducing phosphor temperature to 80oC and light intensity 1000x less, inexpensive and wavelength-tunable organic phosphors used instead of costly and export-restricted rare-earth based inorganic phosphors. We introduce two new innovations improving the system efficiency: 1) Introduce a new set of organic phosphors with significantly higher efficiencies and long lifetimes (50000hrs). 2) Increase the efficacy of the LED light engine by replacing state-of-the-art inefficient light diffusers with efficient diffractive optics complemented with an improved reflectivity of the mixing chambers. OPERA will demonstrate a breakthrough in LED light engines which will DOUBLE the luminous efficacy of the state-of-the-art direct phosphor-converted LED modules. Resulting in two demonstrators: 1) LED engine with efficacy of 130Lm/Watt CCT 2700K with CRI 90 Incandescent 2) LED engine with efficacy of 150Lm/W at CCT 4000K with CRI 80 Fluorescent tube. The consortium addresses the research challenges associated with the remote phosphor optical configuration, efficient stable organic phosphor definition and components for light engine construction. We give European industry an important role in design and manufacturing of optical components based on alternative phosphors for light conversion and light engine construction. We make highly efficient white light engines, based on new organic phosphor materials and compact optics, provide a long-term set of knowledge control points.