A climate-control system comprising: a first working fluid circuit including a first compressor and a first heat exchanger, the first heat exchanger in fluid communication with the first compressor; a second working fluid circuit including a second compressor and a second heat exchanger, the second heat exchanger in fluid communication with the second compressor; and a storage tank containing a phase-change material, the first working fluid circuit and the second working fluid circuit thermally coupled with the phase-change material contained in the storage tank, wherein the first working fluid circuit includes a first conduit and the second working fluid circuit includes a second conduit, and wherein the first and second conduits (24, 31) are disposed within the storage tank, such that working fluid flowing through the first conduit can absorb heat from the thermal storage tank and the second working fluid system, and working fluid flowing through the second conduit can transfer heat to the thermal storage tank and the first working fluid circuit, wherein the climate-control system is operable in a full-charge mode, a discharge mode, a partial charge mode, and a charge-neutral mode, wherein, in the full-charge mode, the second compressor is shut down, and the first compressor operates to circulate working fluid through the first working fluid circuit such that working fluid in the first conduit absorbs heat from the phase-change material contained in the thermal storage tank, wherein, in the discharge mode, the first compressor is shut down, and the second compressor operates to circulate working fluid through the second working fluid circuit such that working fluid flowing through the second conduit transfers heat to the phase-change material contained in the thermal storage tank, wherein, in the partial charge mode, the first compressor operates to circulate working fluid through the first conduit and the second compressor operates to circulate working fluid through the second conduit, such that the working fluid in the first conduit absorbs heat from the phase-change material at a faster rate than the working fluid in the second conduit transfers heat to the phase-change material, wherein, in the charge-neutral mode, the first compressor operates to circulate working fluid through the first conduit and the second compressor operates to circulate fluid through the second conduit such that heat is added to the phase-change material by the second working fluid circuit at the same rate that heat is removed from the phase-change material by the first working fluid circuit, and wherein the second working fluid circuit includes a first loop and a second loop and wherein the first loop and the second loop are in fluid communication with the second conduit. a first working fluid circuit including a first compressor and a first heat exchanger, the first heat exchanger in fluid communication with the first compressor; a second working fluid circuit including a second compressor and a second heat exchanger, the second heat exchanger in fluid communication with the second compressor; and a storage tank containing a phase-change material, the first working fluid circuit and the second working fluid circuit thermally coupled with the phase-change material contained in the storage tank, wherein the first working fluid circuit includes a first conduit and the second working fluid circuit includes a second conduit, and wherein the first and second conduits (24, 31) are disposed within the storage tank, such that working fluid flowing through the first conduit can absorb heat from the thermal storage tank and the second working fluid system, and working fluid flowing through the second conduit can transfer heat to the thermal storage tank and the first working fluid circuit, wherein the climate-control system is operable in a full-charge mode, a discharge mode, a partial charge mode, and a charge-neutral mode, wherein, in the full-charge mode, the second compressor is shut down, and the first compressor operates to circulate working fluid through the first working fluid circuit such that working fluid in the first conduit absorbs heat from the phase-change material contained in the thermal storage tank, wherein, in the discharge mode, the first compressor is shut down, and the second compressor operates to circulate working fluid through the second working fluid circuit such that working fluid flowing through the second conduit transfers heat to the phase-change material contained in the thermal storage tank, wherein, in the partial charge mode, the first compressor operates to circulate working fluid through the first conduit and the second compressor operates to circulate working fluid through the second conduit, such that the working fluid in the first conduit absorbs heat from the phase-change material at a faster rate than the working fluid in the second conduit transfers heat to the phase-change material, wherein, in the charge-neutral mode, the first compressor operates to circulate working fluid through the first conduit and the second compressor operates to circulate fluid through the second conduit such that heat is added to the phase-change material by the second working fluid circuit at the same rate that heat is removed from the phase-change material by the first working fluid circuit, and wherein the second working fluid circuit includes a first loop and a second loop and wherein the first loop and the second loop are in fluid communication with the second conduit.