**1.4 Project justification**

Application of solar energy has speedily improved the present low level of electricity production for domestic lighting and agricultural operations in several developing nations. However, according to the United Nations Development programme, 400milion families (nearly two billion people) have no access to electricity to light their homes, among other services (SELF, 2001).

The power generation potential of several energy harvesting modalities have been investigated (Roundy, 2003). While a wide variety of harvesting modalities are now feasible, solar energy harvesting through photo-voltaic conversion provides the highest power density, which makes it the modality of choice to power an embedded system that consumes several megawatt of energy using a reasonably small harvesting module. However, the design of a solar energy harvesting module involves complex tradeoffs due to the interaction of several factors such as the characteristics of the solar cells, chemistry and capacity of the batteries used (if any), power supply requirements, application behaviour, and power management features of the embedded system etc. It is, therefore, essential to thoroughly understand and judiciously explore these factors in order to maximize the energy efficiency of a solar harvesting module.
