Abstract. Parabolic Trough Concentrators (PTC) are the most common solar concentrators. However, the high cost of production, operation, sun- tracking system, and the environmental sensitivity made them unprofitable for urban contexts. Lenses are more efficient and effective, but the complexity of manufacturing made them less used in sustainable architecture. This research proposes a liquid lens to be integrated into buildings’ envelope and compared with a PTC based on the energy production and reduced CO2 emissions over a year. The output energy, temperature, and efficiency of concentrator are obtained by the physics of light equations, and Ray-tracing software simulation. The results show that water lenses are at least 6% more efficient, their output temperature is higher, their underneath greenhouse effect made them less sensitive to the environment, and are still productive in high latitudes where PTCs are not operative. The paper presents the full result of the research that was registered as a patent.