An inexpensive, rechargeable and reliable electrical power system for marine buoys is proposed. This unique, safe system decomposes seawater to make pure hydrogen to supply a fuel cell, which converts the hydrogen directly to electricity at 50%+ efficiency. The system is passive and insensitive to corrosion or shock. Hydrogen is produced by water reaction near ambient temperature with activated magnesium alloy. The only byproduct is Mg(OH)2 , milk of magnesia. The new Mg alloy has reaction properties with seawater that are ideal for a power source with varying electrical demand and on/off requirements. The fuel cell is a commercially available proton exchange membrane, hydrogen-air unit. The system needs no electronics or moving parts. It will produce about 1.3 kWh per kg of total system weight. Consumable reagents should cost less than $4/kWh. Periods between magnesium alloy recharging can be much longer than six months. During Phase 1 an integrated prototype system will be prepared to work continuously without maintenance. This effort will include optimizing the composition and geometry of the rechargeable magnesium alloy elements; designing an integrated system for buoy requirements (e.g., 35 W for 6 months) and conditions; and testing/optimizing of the selected prototype. It is anticipated that the NAVY will gain from this R&D effort an electrical power source which will have 1.4kWh energy capacity per kg of total weight . This unit can easily be adapted as a power source for marine buoy and produce 35W of electrical energy for 6 months without any maintenance service .This system is ideal for different low power marine applications.
