Increasing the efficiency of water supply networks is essential in arid and semi-arid regions to ensure the supply of drinking water to the inhabitants. The cost of renovating these systems is high. However, customized management models can facilitate the maintenance and rehabilitation of hydraulic infrastructures by optimizing the use of resources. The implementation of current Internet of Things (IoT) monitoring systems allows decisions to be based on objective data. In water supply systems, IoT helps to monitor the key elements to improve system efficiency. To implement IoT in a water distribution system requires sensors that are suitable for measuring the main hydraulic variables, a communication system that is adaptable to the water service companies and a friendly system for data analysis and visualization. A smart pressure monitoring and alert system was developed using low-cost hardware and open-source software. An Arduino family microcontroller transfers pressure gauge signals using Sigfox communication, a low-power wide-area network (LPWAN). The IoT ThingSpeak platform is used for data analysis and visualization. Additionally, the system can send alarms via SMS/email in real time using the If This, Then That (IFTTT) web service when anomalous pressure data are detected. The pressure monitoring system was successfully implemented in a real water distribution network in Spain. It was able to detect both breakdowns and leaks in real time.
Increasing daylighting levels contributes to improving the energy efficiency of buildings and consequently to the fight against climate change. This work presents a new illuminator based on a previous single-axis polar heliostat. This heliostat allows redirecting sunlight to a specific space to be illuminated at any time of the day. The system presented is simple but compact in size. It has been manufactured by 3D printing with recyclable PETG plastics. Three-dimensional printing has allowed reduction of the mass of the system to less than 5 kg, which means high stability and manageability. Moreover, the system has been provided with an assembly structure that facilitates its correct installation by a single operator. The result is a heliostatic illuminator with an average pointing error of 10 mrad, an acceptable error for urban applications. Finally, a low-cost and high-replicability device has been achieved, which makes it an easily reproducible illuminator and favors its extensive installation.
Abstract.Stochastic simulation methods are normally extended as the only available to assess the reliability of the PV system implies the generation, for an extended period of time, of the main state variables of the physical equations describing the energy balance of the system, that is, the energy delivered to the load and the energy stored in the batteries. Most of these methods consider the daily load as a constant over the year and control the variables indicating the reliability associated with the supply of power to the load. Furthermore, these methods rely on previous random models forgenerating solar radiation data and, since the approximations of the simulation methods are asymptotic, when more precise reliability indicators are required, the simulation period needs to be extended. This paper presents a mathematical methodology to address the daily energy balance without resorting to simulation methods.
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