During the energy transition, geophysics will need to focus on novel green energy applications and to reduce the carbon footprint of hydrocarbon production. For both reservoir, monitoring is important, in particular dynamic monitoring of reservoir fluids. For renewable energies such as geothermal, electromagnetics has always been the geophysical ‘work horse’, while mostly microseismic has been used for monitoring. For hydrocarbon reservoirs, added value toward ZERO carbon footprint is obtained by increasing the recovery factor by of 30-40 % and thus reducing the cost/carbon emission per produced barrel. In addition, CO2 is sequestered in brine saturated reservoirs and also needs to be monitored. We are addressing the fluid monitoring issue here for electromagnetics and are reviewing how hardware, methodology and application are interlinked to build a complete system. Various applications and case histories where the results can be verified by borehole logs support this. The key issue is that our measurement need to respond to geologic realistic Earth formations which are, generally speaking, anisotropic. We direct the entire design of the system in solving that problem with direc-tional sensitive measurements. Next, when we want to monitor reservoir change we require a repeatability and accuracy hereto not necessary. By carefully controlling the entire hardware design from sensor to applications stage this can be achieved and we can obtain log scale resolution from surface measurement which was hereto not possible.