Stratospheric Grid: A Wireless Power Transfer Enabled HAP Network with Integrated Generation-Grid-Load-Storage Functions
Peng Wang, Eros Kuikel, Jia Ye, Mohamed-Slim Alouini
TL;DR
The paper confronts the energy bottlenecks of high-altitude platforms by proposing a stratospheric energy grid built on wireless power transfer that interconnects HAPs as dynamically reconfigurable IGGLS nodes. It outlines two WPT modalities (RF and optical) and details how generation, load, and storage on HAPs can be co-optimized to reduce daytime curtailment and extend nighttime endurance, enabling constellation-scale energy balancing. A broad ecosystem perspective introduces cross-layer energy relay, RIS-assisted routing, and distributed aerial storage to connect space, air, and ground energy sources, with case-study results showing substantial efficiency gains and resilience. The work suggests a roadmap for intelligent beam control, AI-driven optimization, and security measures to realize a scalable, secure multi-layer energy web for future 6G networks.
Abstract
Conventional high-altitude platforms (HAPs) face challenges in achieving continuous all-weather operation due to intermittent photovoltaic power generation, limited energy storage capacity, and high mission loads resulting from functional integration. To address this fundamental issue, we propose a stratospheric energy grid in which wireless power transfer (WPT) interconnections constitute the grid layer, while HAPs operate as dynamically reconfigurable integrated generation-grid-load-storage (IGGLS) nodes that harvest, buffer, consume, and peer-to-peer transfer energy for constellation-level balancing and resilience. In this system, each HAP node can flexibly switch among energy source, load, and storage roles according to its energy status and mission requirements, enabling energy exchange and spatiotemporal optimization within the stratosphere. Through cooperative scheduling, the stratospheric grid not only enables surplus-to-deficit energy support among HAPs but also extends upward to satellites and downward to the terrestrial grid and communication infrastructure, forming a heterogeneous, WPT-mediated interconnection. As an IGGLS ecosystem, it exploits peer-to-peer energy logistics, spatiotemporal smoothing of intermittency, cross-domain backup via the terrestrial grid, and service-aware dispatch, thereby boosting overall energy utilization and operational resilience. The proposed approach is validated through case studies, and we delineate an agenda of feasible research directions.