Maximization of solar power extraction from photovoltaic modules using energy harvesting solutions for smart cities

Abstract

Smart cities integrate a wide and diverse set of small electronic devices that use Internet communication capabilities with very different purposes and features. A challenge that arises is how to feed these small devices. Among the various possibilities, energy harvesting presents itself as the most economical and sustainable. This paper describes the design and simulation of an electronic circuit dedicated to maximizing the solar power extraction from photovoltaic (PV) modules. For this purpose, an integrated circuit (IC) dedicated to energy harvesting is used, namely the LTC3129. This IC is a DC-DC converter that uses the maximum power point control (MPPC) technique, which aims to keep its input voltage close to a defined reference value. The designed circuit is used with three photovoltaic modules, each one of a different PV technology: monocrystalline silicon, polycrystalline silicon and amorphous silicon. These PV modules are installed in a weather station to correlate the power produced with the meteorological conditions, in order to assess which solar photovoltaic technology is best for a given location. The equivalent circuit of a solar cell is used in simulation to represent a photovoltaic module. The values of the components of the equivalent circuit are adjusted so they have the same characteristics of the modules installed in the weather station. With each module, a power resistor of the same value is used as load, for comparison purposes. For the case of the monocrystalline silicon technology, the use of the LTC3129 converter increases the power extraction by 47.6% compared to when this converter is not used between the PV module and the load.