A practical theory of micro-solar power sensor networks

Abstract

Autonomous long-term monitoring is an essential capability of wireless sensor networks, and solar energy is a viable means of enabling this capability due to its high power density and wide availability. However, micro-solar power system design is challenging because it must address long-term system behavior under highly variable solar energy and consider a large space of design options. Several micro-solar power systems have been designed and implemented, validating particular points in the whole design space.In this dissertation we develop a practical theory of micro-solar power systems that is materialized in a simulation suite that models component and system behavior over a long time-scale and in an external environment that depends on time, location, weather and local conditions. This simulation provides sufficient accuracy to guide specific design choices in a large design space. This design tool is very different from the many "macro-solar" calculators, which model typical behavior of kilowatt systems in the best conditions, rather than detailed behavior of milliwatt systems in the worst conditions. We provide a general architecture of micro-solar power systems, comprising key components and interconnections among the components, and formalize each component in an analytical or empirical model of its behavior.We incorporate these component models and their interconnections in the simulation suite.Our discrete time-event simulation models the daily behavior and the long-term behavior by iteratively evaluating the state of the system in the context of its solar i

SensEH: From simulation to deployment of energy harvesting wireless sensor networks

“…It is cycle-accurate because it is based on the SystemC framework, which significantly increases simulation time. In a similar vein, system-level simulators [9], [10] trade simulation speed for more accurate modeling of low-level details of the harvesting system. The complexity of these models is a major obstacle to their adoption for assessment of EH systems.…”

“…Wu et al [4] Sanchez et al [5] HarvWSNet [6] GreenCastalia [7] WSNsim [8] Jeong & Culler [9] SIVEH [10] PASES [11] TOSSIM [12] COOJA/MSPSim [1] SENSEH applications, while COOJA coupled with MSPSim, a hardware emulator for MSP430-based motes, allows simulation of both Contiki and TinyOS applications. However, neither include support for modeling power consumption or battery discharge, let apart energy harvesting.…”

A Method for Dimensioning Micro-Scale Solar Energy Harvesting Systems Based on Energy Level Simulations

“…A well established model for solar panels is described in [6], [7] and further, a more detailed modeling of internal cell operation has been covered in [8]. When it comes to energy storage, battery modeling has been addressed in [9] and a double layer capacitor model is proposed in [10]. In [11] a general overview of energy device modeling and combination is given.…”

“…Work related to this topic was addressed in [9], [12], [13]. In [12] analytical prediction of harvested energy and consequence for battery charge level is examined.…”

Integrated Reciprocal Conversion With Selective Direct Operation for Energy Harvesting Systems

“…A typical energy harvesting sensor system is shown in Fig. 1 [1]. For this work, the CPU and its associated elements are referred to as the 'CPU system'.…”