Abstract: A carbon-based energy system including an apparatus for generating electricity and byproduct CO2, a photosynthesis bioreactor that converts CO2, and a CO2 storage unit. In one embodiment, the energy system includes a direct carbon fuel cell (DCFC), a photosynthetic bioreactor, and a thermoacoustic cooler. Also provided is a method for reducing CO2 emission in energy systems achieved by coupling a photosynthetic bioreactor and a CO2 storage system with an energy system wherein the CO2 produced by the energy system is converted to biomass during light hours and is stored during dark hours.