A KAIST research team led by Professor Hyun Jung Kim in the Department of Aerospace Engineering has proposed a pioneering concept called the Lunar ElectroStatic Power Generator (L‑ESPG). This system envisions harvesting energy from electrostatic charges naturally built up on the Moon’s surface. Unlike traditional power sources, the proposed L‑ESPG would not rely on sunlight or chemical fuel. Instead, it seeks to tap into one of the Moon’s most overlooked energy reservoirs: negative surface charge.

On the Moon, night lasts 14 Earth days, and temperatures plunge below –170°C. In such darkness, solar panels become unusable, and batteries or radioisotope thermoelectric generators (RTGs) offer only limited solutions, each with drawbacks in cost, lifetime, or safety. Yet the lunar night may offer an alternative: electrostatic energy. The Moon’s surface, exposed to solar wind electrons and intense ultraviolet radiation, accumulates significant negative electric charge, especially on the nightside and inside polar craters. This unique electrostatic environment, long treated as a hazard, is now being reimagined as an opportunity.

Professor Hyun Jung Kim’s team in the Department of Aerospace Engineering at KAIST has proposed the Lunar ElectroStatic Power Generator (L‑ESPG), a system that harvests energy from naturally accumulated electrostatic charges in lunar regolith. Unlike conventional systems, the proposed L‑ESPG does not rely on sunlight or chemical fuel, instead tapping into one of the Moon’s most overlooked energy reservoirs: negative surface charge.

| “Rather than treating electrostatic charge as a hazard, we designed a system to capture and neutralize it—turning a problem into a power solution. This concept is illustrated in Movie 1.”— Professor Kim, PI of STAR Lab

The proposed L‑ESPG system places electrodes in contact with the negatively charged lunar surface. As charge flows into the system, it could be harvested as usable electrical energy. Simultaneously, this mechanism has the potential to neutralize surface charge, mitigating problematic effects such as dust levitation and instrument contamination, phenomena that have plagued lunar missions. This dual-use concept, power harvesting and dust mitigation, aims to address critical needs for long-duration exploration, especially in permanently shadowed regions where solar energy is scarce but electrostatic charge is expected to accumulate significantly.

Since 2025, the research team has taken initial steps toward realizing L‑ESPG, including developing the first near-global electrostatic potential map of the Moon, demonstrating early-stage ESPG prototypes under simulated lunar conditions, and advancing designs for deployable ESPG arrays, in collaboration with Prof. Dae-Young Lee’s group.

Contributions from Gyeong-ji Kang (Prof. Lee’s group) and Min-hyuck Kim (Prof. Kim’s group) have been pivotal in refining system design and conducting experimental validations. Preliminary modeling suggests that under realistic lunar potentials, a full-scale ESPG array could achieve power outputs exceeding 500 W, illustrating the system’s potential for meaningful energy generation. Ongoing work in 2026 is focused on circuit integration, scaling up large-area arrays, and optimizing materials for lunar deployment conditions. These efforts aim to evaluate the feasibility of transitioning L‑ESPG from a conceptual framework to a flight-ready subsystem.

Looking ahead, L‑ESPG is being explored as a power generator and as a real-time electrostatic sensing platform for future landers and rovers. The system’s scalability and passive operation model make it attractive for supporting next-generation lunar infrastructure, such as in-situ resource utilization (ISRU), autonomous construction, and long-duration habitation in shaded regions. The concept’s flexibility may also extend beyond the Moon. For example, highly electrified environments such as the Venusian atmosphere could support ESPG-like systems, enabling charge-neutralization and energy harvesting in airship-based missions.

“This is more than just a power generator. It’s a potential infrastructure platform for sustainable lunar presence.” — Professor Kim

This conceptual research, conducted with Mr. Alazar Teka Gemechu (2025 long-term URP), was awarded the Silver Prize at the 2025 Space Grand Challenge hosted by the Hanwha Space Hub–KAIST Space Research Center, for the presentation titled “From Lunar Static to Knowledge and Power – Enabled by Sensing” (2025.12.18). The work is currently supported by the Basic Research Program (GP2023-001) of the Korea Institute of Geoscience and Mineral Resources (KIGAM).