A co-located multi-energy system that integrates renewable generation, waste-energy recovery, desalination, and storage can asymptotically approach zero marginal energy cost by converting spatial, thermal, and temporal inefficiencies into productive work.

This research paper explores the design and feasibility of a co-located, multi-source coastal energy ecosystem aimed at asymptotically approaching near-zero marginal energy cost through systems integration rather than novel energy creation. The central hypothesis is that energy scarcity is not primarily a generation problem, but a systems and inefficiency problem, driven by spatial separation, single-purpose infrastructure, and the loss of low-grade energy to the environment.

The study investigates the strategic co-location of complementary renewable and low-carbon energy sources—solar photovoltaic and solar thermal, onshore and offshore wind, geothermal (where available), and ocean-based energy systems including tidal, wave, and ocean thermal energy conversion (OTEC). By situating these sources near coastal zones, the system exploits continuous access to seawater for cooling, thermal exchange, desalination, and pumped storage, while minimizing transmission and conversion losses.

A key research focus is the integration of secondary energy recovery mechanisms, particularly waste heat and pressure recovery. Excess thermal energy from power generation, industrial processes, data centers, and desalination plants is captured via organic Rankine cycles, absorption cooling, and thermal storage. Pressure energy from desalination brine discharge and pumped water flows is recovered using hydraulic turbines, transforming traditionally lost energy into usable work. These cascaded energy flows are matched to tasks requiring progressively lower energy quality, aligning with exergy optimization principles.

The paper synthesizes knowledge from thermodynamics, renewable energy engineering, industrial ecology, water–energy nexus studies, and systems engineering. It applies exergy analysis and energy cascading frameworks to evaluate how co-location and functional integration outperform isolated high-efficiency components. Desalination is reframed not as an energy burden but as a system amplifier, producing potable water, enabling pumped storage, supporting agriculture and aquaculture, and stabilizing thermal loads.

Results from modeled system scenarios demonstrate that while total energy input remains finite and bounded by physical laws, usable work per unit of generated energy increases substantially when waste streams are systematically reutilized. The findings indicate significant reductions in curtailment, storage overbuild, and peak-load inefficiencies. Under optimized configurations, the system approaches a condition where additional energy demand can be met with minimal incremental generation, effectively driving marginal energy costs toward zero.

The research concludes that a coastal, integrated energy ecosystem represents a viable pathway toward an energy “utopia” grounded in physics—defined not by limitless energy, but by the near-elimination of waste, redundancy, and idle capacity through intelligent design.