Grid Scale, Solar, Storage

U.S. Renewables Lab Wins Three Research Awards

The National Renewable Energy Laboratory has won three more awards for the development of innovative technology.

GOLDEN, Colorado, US, 2001-10-16 [] Since 1982, the U.S. Department of Energy lab has won 28 awards in the annual ‘top 100′ competition sponsored by R&D Magazine. The three awards in this year’s event are for a high-efficiency solar cell, an antenna that reconfigures itself to direct its power at selected subscribers, and a battery charger capable of extending the cycle life of lead-acid batteries. The triple junction solar cell reached conversion efficiency of 34 percent under a concentration of 400 suns, which is the insolation level in concentrator arrays. The TJ cell was developed by NREL and Spectrolab Inc, and has the potential to generate large amounts of electricity at prices competitive with conventional systems. The Dynamically Reconfigurable Wireless Networks (DRWiN) electronically scanning antenna is the world’s first low-cost unit that enables higher quality and more reliable wireless service to a larger customer base within a given geographic area. The unit can reconfigure itself from broad beam to narrow beam in order to direct information to selected subscribers, and then reconfigure back to broad beam to acquire new subscribers requesting service. This leads to the ability to serve more customers with higher quality data transfers which, in turn, produces increased revenue for service providers. Most lead-acid batteries are recharged using a simple interrupt charging algorithm that extends the cycle life of batteries by 300 to 400 percent. Batteries in electric vehicles can only last for 200 deep discharge cycles, primarily because they have been charged using a constant current and voltage. NREL, Recombination Technologies and Optima Batteries devised a method to apply a current to the battery for five seconds to overcharge the battery slightly, then interrupt the current for five seconds. This allows the battery to cool and avoid going into the oxygen recombination cycle, which leads to early failure of the negative battery plate due to oxidation of sulfuric acid into sulfate.