A Unified Value Signal Driven Strategy for Coordinated Multi-Energy Optimization in Building Clusters

China’s transition toward an energy powerhouse requires not only a secure and low-carbon energy supply but also flexible and efficient coordination of distributed resources at the demand side. Building-cluster integrated energy systems couple electricity, heat, and cooling, whose transport dynamics, useful-work potential, and carbon responsibilities differ substantially. Conventional energy-based metrics therefore cannot fully capture how network states and energy quality affect nodal marginal values. This study proposes a unified value-signal-driven strategy for coordinated multi-energy optimization in building clusters. First, a coupled energy–carbon flow model represents the hydraulic–thermal dynamics, transport delays, and virtual thermal storage of the heating network, enabling the spatiotemporal tracing of heat and its associated carbon responsibility. Second, exergy is adopted as a common physical basis, while energy quality factors and exergy–carbon potentials quantify carrier-specific useful-work potential and carbon responsibility. An economic and low-carbon dispatch model is then formulated, and the generalized marginal exergy price is defined as the full KKT-based envelope derivative of the optimal value with respect to nodal exergy demand in a continuous convex pricing subproblem. In a four-cluster case study, the load-side response delays obtained from the steady-state, quasi-dynamic, and fully dynamic models are approximately 0, 25, and 55 min, respectively. Relative to unoptimized operation, the proposed strategy reduces daily total cost by 15.66%. Relative to energy-based optimization, it further reduces total cost by CNY 1,591.79 and increases average exergy efficiency from 56.11% to 66.50%, while carbon cost increases by CNY 842.50. Across nine finite-difference tests, the mean and maximum relative errors of the KKT-based marginal values are 0.0391% and 0.1570%, respectively. The framework provides a demand-side mechanism for coordinating local multi-energy resources and supports the development of a more secure, flexible, and low-carbon energy system.