Abstract: In response to the nation’s imperatives for clean energy transition and carbon neutrality, efficient full-spectrum utilization of solar energy and low-carbon utilization of fossil fuels have attracted widespread attention. Based on the fundamental thermodynamic principle of “matching energy quality with end-use requirements and cascaded utilization, ” this study proposes a novel distributed energy system that deeply integrates spectral splitting technology, chemical looping combustion, and methanol synthesis, featuring inherent carbon capture and utilization. In the proposed system, a spectral splitter directs photons in the visible range to photovoltaic cells for high-efficiency electricity generation. The generated electricity primarily powers a solid oxide electrolysis cell to produce green hydrogen via water electrolysis. Meanwhile, photons outside this range are channeled to a solar-thermal collector to supply the medium-to-low temperature heat required for the CLC process, enabling near-zero-energy-penalty CO₂ capture. The captured high-purity CO₂ is subsequently catalytically hydrogenated with renewable H₂ to synthesize liquid methanol—transforming conventional carbon sequestration into carbon resource utilization and yielding a storable, transportable green fuel. The thermodynamic process of this multi-energy complementary distributed system was modeled using Aspen Plus and Matlab, followed by sensitivity analyses of key operational parameters. Results show that when photons within the 414–1 100 nm band are allocated to PV conversion and the rest to solar-thermal conversion, the system achieves optimal performance: under the first law of thermodynamics, the full-spectrum solar energy utilization efficiency reaches 39.34%, approximately 6 percentage points higher than that of a reference system without spectral splitting; the overall energy conversion efficiency reaches 47.86%, an improvement of nearly 3 percentage points. From the second-law perspective, the solar full-spectrum exergy efficiency is 35.20%, which is 12 percentage points higher than that of the reference system, while the total system exergy efficiency reaches 30.39%, an increase of 3 percentage points. This integrated approach—combining full-spectrum solar energy conversion, chemical looping combustion, and CO₂ hydrogenation to methanol—offers an innovative pathway toward near-zero-carbon-emission carbon-based distributed energy systems.