# Exploring the Feasibility of Autonomous Lighting Systems for Pedestrian Crossings in Off-Grid Areas
## 1 Introduction
### Relevance of the Subject Matter
An intelligent energy-efficient street-lighting system with a dedicated predictive control algorithm is presented in [19]. Based on an internet weather forecast, the algorithm predicts the energy consumption and operating time for several days ahead. Streetlights are equipped with PV panels and single-axis solar trackers for proper orientation relative to the sun. In addition, the system contains batteries, motion mechanisms, and light intensity sensors. The control system is equipped with an XBee3 wireless module, enabling communication, monitoring, and control of several streetlights simultaneously. This type of system is under tests by many researchers worldwide [20; 21; 22]. A simulation model of a dedicated street lighting system using LED light sources, powered by PV panels and batteries, is also described in [23]. This autonomous lighting system is presented from the electrical point of view. The authors focused on studying the time waveforms of voltages and currents occurring in the system as a function of available solar energy and battery capacity. The research was performed using a simulation model developed in Matlab. The analyses concerned the response of the system to the efficiency of the PV converter under varying values of load power and sunlight intensity. Ref. [24] presents the integration of a solar system with road lighting based on the nano-grid concept, an improvement of traditional road lighting using LED technology and PV. The power quality of the proposed nano-grid is tested and analyzed in different modes: stand-alone and grid-connected, using an experimental test stand. The authors concluded that the integration of a PV power system into a road lighting system, based on the nano-grid concept, offers high economic efficiency for investment. Autonomous installations at pedestrian crossings are also used to supply power for traffic lighting systems [25] where photovoltaic panels and piezoelectric transducers are used. The system proposed in the article collects energy from sunlight and vibrations at the roadway crossing and converts it into electric energy. The concept of combining photovoltaic and thermal technology is also being used to achieve higher efficiency for energy production [26]. According to European recommendations [27], these solutions can also be used to supply power to road lighting installations. Solar street lighting is a key technology that can be a part of a country's sustainable development, especially in high sunlight emission regions [28]. According to the authors, the implementation of innovative solutions requires a critical approach to the used technologies. Alternative power solutions can also be used on roundabouts [29]. The installation of photovoltaic panels on the road surface is considered in [30]. An extremely important issue related to extending the lifetime of light sources is the reduction in their operating temperature. In [31], four different ways of powering discharge light sources (HID) and their influence on the temperature of the plasma channel and emission of the luminous flux are presented. The study investigates the supply power of the discharge lamp using an electromagnetic ballast operating at a main frequency of 50 Hz and an electronic ballast, allowing the generation of different time waveforms of HID lamp currents. It effectively communicates the idea that applying the appropriate current waveform to the discharge lamp can reduce the temperature of the plasma channel, leading to an increased operating lifespan for this type of light source. Control algorithms for lighting infrastructures [22] are becoming a critical component of a Smart City [32]. A smart LED street lighting system with the Internet of Things (IoT)has become an alternative to conventional illumination systems. The presented solution makes it possible to control the intensity of the light and monitor luminaire parameters. Such information is important from a maintenance point of view.