Sustainable Power Management for Mobile Computing

Renewable energy sources have been integrated into Mega-Watt (MW) power utility systems and very low power applications with milli-Watt (mW) consumption. There is very limited work in this area for commonly available mobile computer systems operating in the range of a few Watts to tens of Watts. This paper investigates the use of renewable energy sources and the associated power electronics for low power mobile computers. Sustainable power management architectures have been explored for improved "Performance per Watt", including thermoelectric (TE) and photovoltaic (PV) energy conversion. A renewables link to the system DC bus has been added to the mobile power architecture. Various platform form factors have been analyzed using a combination of visual basic models for TE, finite-element analysis (FEA) for thermals, spreadsheet calculations for PV energy conversion based on realistic assumptions, and SPICE simulations for the power electronics. 10% or more improvement in Performance/Watt is conceivable based on preliminary analysis performed on the standard Thin and Light systems. The first prototype has been developed for the Hybrid Thermoelectric Conversion (HTC) system along with the associated power electronics design and validation. The rest of the system will be added in stages to the prototype.