A practical theory of micro-solar power sensor networks

Building a micro-solar power system is challenging because it must address long-term system behavior under highly variable solar energy and consider a large design space. 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 variations. This simulation provides sufficient accuracy to guide specific design choices in a large design space. Unlike the many macro-solar calculators, this design tool models detailed behavior of milliwatt systems in the worst conditions, rather than typical behavior of kilowatt systems in the best conditions. Our simulation suite is validated with a concrete design of micro-solar power systems, the HydroWatch node. With our simulation suite, micro-solar power systems can be designed in a systematic fashion. Putting the model and empirical vehicle together, the design choices in each component of a micro-solar power system are studied to reach a deployable candidate. The deployment is evaluated by analyzing the effects of different solar profiles across the network. The analysis from the deployment can be used to refine the next system-design iteration.