The current levelized cost of energy (LCOE) from concentrated solar power (CSP) is ~ $0.11/kWh. The U.S. Department of Energy has set goals to reduce this cost to ~$0.07/kWh with 6 hours of storage by 2015 and to ~\$0.05/kWh with 16 hours of storage by 2020. To help meet these goals, scientists at Argonne National Laboratory are working to improve the overall CSP plant efficiency by enhancing the thermophysical properties of heat transfer fluids (HTFs). By adding multifunctional nanoparticles to a fluid, researchers have demonstrated improved thermal conductivity and energy storage. Results show a 20% enhancement in thermal conductivity over base fluid (Therminol66) at 2 volume percent (vol%) of copper nanoparticles. (Point of Contact: Dileep Singh, Argonne Nuclear Engineering Division)