... portable energy Solar energy is a proven, yet underdeveloped, clean energy resource. In the last few decades, considerable research has gone into trying to lower its cost and improve the efficiency of standard solar collectors those with power outputs greater than 200 W, such as photovoltaic...

...Raúl Zimmerman; Graham Morrison; Gary Rosengarten Proton exchange membrane fuel cells (PEMFCs) are good candidates for portable energy sources with a fast response to load changes, while being compact as a result of their capability to provide a high power density. Hydrogen constitutes the fuel...