Product Code: ICAL07_M1103

Demonstrated Fossil-Fuel-Free Energy Cycle using Magnesium and Laser (Invited Paper - 40 Minute Presentation)
Authors:
Kunio Yoshida, Tokyo Institute of Technology; Tokyo Japan
Takashi Yabe, Tokyo Institute of Technology ; Tokyo Japan
Shigeaki Uchida, Tokyo Institute of Technology; Tokyo Japan
Presented at ICALEO 2007

There is no doubt that we need an energy cycle free of fossil fuels that otherwise emit greenhouse gases causing global warming. Although solar energy is the ultimate renewable energy source, sunlight is available only in the clear daytime and hence it cannot be an alternative to thermal power stations unless effective and large power storage systems are available. Here we propose the chemical potential of magnesium as such an energy reservoir. Heat and hydrogen from the reaction of magnesium with water are used for turbines, reciprocal engines, fuel cells, and so on. The remaining ash, MgO, is deoxidized by the energy from a solar-energy-pumped laser. Once such MgO deoxidization technology is developed, unsteady solar power can be stored in Mg form to provide a stable supply of energy. This paper reports experimental demonstrations of key technologies. We have achieved 14% slope efficiency from natural sunlight source to laser output by Cr-doped Nd-YAG laser and 1.4-m2 Fresnel sunlight collector, and 42.5% energy recovery efficiency for deoxidization of MgO