Balancing the power supply and load is an iterative process. In general, the overarching constraints are form factor and cost. Within these constraints, engineers have to select an energy harvesting device, a PMIC, and an energy storage device to supply power. The power supplied by the selected device must then be compared with the power demand, or EHS load, of the WSN over time. When supply cannot meet demand, the engineer must reiterate by making more power available, by modifying the EHS, often adding cost, or by changing components, and/or the behavior of the EHS load. Cypress' easy DesignSim software tool, simplifies this iterative process by allowing the designer to capture the key performance parameters of an EHS, an EHS load, and providing a simple pass/fail analysis. This eliminates the need for a designer to create manual calculations that are prone to error, saving design time.