Solar-powered street lighting system with weather-adaptive control

Abstract

A self-sufficient, solar-powered lighting system, comprising: a) a photovoltaic module (5) for converting solar energy into electrical energy, b) a rechargeable lithium iron phosphate battery (LiFePO4) (9) for storing the generated energy, c) at least one dimmable LED light (3) for illumination, d) a control unit with a microcontroller (13) and integrated control software, e) a communication module (17) for wireless data transmission (NB-IoT, LTE, or 4G), f) a sensor (11) for detecting the battery state of charge (SOC), g) a motion sensor (8) for detecting movements and determining the movement speed, h) program logic for dynamically controlling the light intensity, wherein at least the parameters battery state of charge (SOC), detected movement speed, and current and forecast weather data are evaluated,i) an energy output module for providing surplus energy to external consumers or for feeding into the local power grid, characterized in that the lighting unit has a reduced basic brightness in the idle state and, upon detection of movement, is increased to different brightness levels depending on the speed of movement, with additional animal-friendly transitions during switching on and off being provided, and the system preemptively charges the battery to the maximum value in the event of forecast bad weather in order to ensure extended self-sufficiency.

Description

Technical Field:The invention relates to an autonomous, solar-operated lighting system with an intelligent control unit ( 13). This takes into account both the current state of charge of the battery and movement data from the environment and meteorological information-including current and predicted values such as temperature, degree of vaulting, solar radiation, amount of precipitation and snowfall. The aim is an adaptive light control for optimizing the energy consumption and for extending the battery life.The system is suitable in particular for areas with low infrastructure requirements, such as parks, wheel and foot paths, transit landings or other public traffic areas. In addition to the illumination, it can optionally emit excess energy to external consumers in order to use the generated energy as efficiently as possible.Background of the Invention:Conventional solar-powered lights are often inefficient because they are based on rigid control mechanisms. Many of these systems have functions such as time-based brightness reduction or simple movement detection. In practice, this frequently means that the luminaire is operated at full brightness (e.g. 100%) for a defined period of time after the dark has broken down and then changes permanently to a predefined dimming level (e.g. 30%), independently of actual environmental conditions, the lighting conditions or the battery state of charge Even in the case of movement detection, the switching usually takes place only between fixed brightness values (e.g. 30% basic operation / 100% in the case of movement), without taking into account additional parameters such as movement speed or energy availability.Modern systems increasingly integrate weather data into the control logic, but in many cases take into account exclusively current or predicted weather conditions without linking this information to the state of charge of the battery or to the actual use situation.This limited reactivity leads to inefficient energy use, higher wear of the energy stores and limited functionality-in particular in changing light, weather or use conditions. An adaptive, multi-dimensional control, which takes into account not only weather forecasts but also battery charge status, movement dynamics and ecological aspects, is only insufficiently implemented in current systems.Object of the invention:The present system aims at developing a smart, energy efficient lighting system that flexibly adapts to different environmental and usage scenarios.The aim is to optimize charging cycles by dynamic control, to extend the battery life and at the same time to minimize energy consumption.The system responds to weather conditions, times of day, and movements in the environment. The light intensity is automatically adjusted to the conditions, thereby reducing light pollution and controlling lighting as needed. A particular consideration is in animal friendliness: the light system uses smooth transitions in adapting to twilight in order to disturb the natural environment as little as possible. The speed of detected objects also enters the light regulation in order to illuminate in a targeted and efficient manner.A central element is the connection to a cloud platform via NB-IoT, LTE or 4G. This enables intelligent remote control, monitoring and early detection of anomalies in system behavior. Excess energy can additionally be used to supply external consumers, such as charging stations, WLAN hotspots or optionally for feeding into the power grid.In addition, the system can be networked into cluster structures, so that a plurality of units can cooperate in a coordinated manner. For natural-oriented or design-focused applications, integration into aesthetically pleasing robin wood piles (1) is provided, whereby the system fits harmonically into the landscape image.Novelty of the invention:The present invention combines for the first time several technological and ecological innovations in a single lighting system, which have not been realized up to now in this combination. A central feature is the optional use of naturally-grown robinia wood piles (1) as a lasting support structure. This material is distinguished by outstanding resistance to weathering and long service life--and even without chemical treatment. This allows for environmentally friendly and aesthetically pleasing integration in environments that are near-natural.In addition, the system has an adaptive control unit ( 13) which uses not only current environmental conditions but also meteorological predictions. In combination with intelligent movement detection (8) and the current SOC of battery (9), this allows a dynamic adaptation of the light intensity according to requirements, with the aim of using energy as efficiently as possible.A further innovative aspect is the optional function for energy delivery. Surplus generated energy can be used flexibly for supplying external consumers such as charging stations, WLAN access points or-if technically provided-for feeding into the power grid.The phantom combination of these elements clearly cancels the system from existing solutions. It offers a robust, autonomous and future-oriented alternative for areas with a low infrastructure connection and for modernizing existing lighting systems. Modular construction, significantly extended battery life, and flexible scalability help to permanently increase acceptance in cities, communes, and infrastructure equipment operators.General Description of the Invention:The proposed lighting system consists of a combination of intelligent, energy-efficient components which together ensure a reliable, autonomous light supply.The central element is a powerful photovoltaic module (monocrystalline, at least 40 W-depending on the place of use) ( 5) which converts solar energy into electrical energy. This is stored in a long-lived lithium iron phosphate battery (LiFePO 4, at least 20 Ah) ( 9). The charging process takes place via an MPPT charging controller ( 10), the control of which takes place by the microcontroller ( 13). The aim is the preferred operation of the battery in the optimum state of charge (SOC) range between 30% and 70%, or 20% and 80%, in order to significantly extend the service life of the battery (9).For precise monitoring of the SOC, an INA 226 sensor ( 11) is used, which measures current, voltage and power in real time and forwards these data to the microcontroller ( 13). If the SOC reaches the upper limit value of 80%, preferably 70%, the feeding via the charge controller ( 10) is stopped. Optionally, excess energy can be intelligently diverted and made available to external consumers.The illumination is effected by high-efficiency LED chips (at least 200 Im / W) ( 3), the luminous intensity of which is adapted depending on the situation-either to a dimmed base level in the rest state or to an increased brightness when movement is detected. This dynamic control is based on data from an integrated motion sensor (optionally microwave or PIR technology) ( 8) as well as on environmental information.An ESP32 microcontroller (13) with Bluetooth and 4G / LTE functionality (17) forms the central control unit. In addition to the sensor data, it also processes external information which is obtained from a cloud platform (e.g. AWS, Azure, Google Cloud or Open Telecom Cloud) via an integrated NB-IoT, LTE or 4G communication module (17). Through the connection to APIs such as OpenMeteo, the system receives weather forecasts (e.g. degree of vaulting, sun hours, precipitation and many more). This information is used together with the current SOC for calculating optimum brightness levels-both for basic operation and when movement is detected.Optionally, the system can be extended by an energy delivery module which can provide excess energy for supplying external consumers (e.g. charging stations, WLAN hotspots or smart city components).Modular Construction and Plug-and-Play ConceptThe lighting system is modular in construction to allow easy installation, maintenance and extensibility. All central components-in particular the solar module ( 5), the battery unit ( 9) and the LED modules ( 3)-are connected to one another via plug-and-play interfaces and can be exchanged without a special tool.The solar module ( 5) is designed as an upper termination of the housing and functions as a type of cover ( 16), comparable to a shoe-box cover ( 16), which slightly protrudes beyond the housing below. It is fixed via lateral screw connections and is electrically connected to the charging controller ( 10) via a pluggable connection.The battery (9) is accommodated in a separate compartment (4) below the main housing (6). The battery (9) can be removed or used in an uncomplicated manner and is likewise connected to the system via pluggable connections.The LED lamps ( 3) are also of modular construction. A plurality of LED modules ( 3) are organized in groups and connected via separate plug connections. The connecting cables are guided through recesses ( 14) in the housing, so that the modules can be easily mounted and exchanged if necessary. These recesses (15) also exist for the plug-and-play connections of the battery (9).Adjustable Light HolderIn order to ensure illumination according to requirements in various installation situations, the housing ( 6) is connected to the mounting bracket ( 7) via an adjustable bracket ( 2). This holder (2) allows individual adjustment of the angle of inclination of the luminaire relative to the ground. The adjustment takes place via predefined locking positions and thus enables an optimum alignment of the light cone according to the environment.Example Control Logic:The control logic of the system intelligently adjusts the lighting to the respective conditions and thereby takes into account the state of charge of the battery (SOC), weather data, current twilight phases and movement speeds in the environment.Twilight-based background brightness:The system uses, for example, the OpenMeteo API to determine the exact time of evening and morning deciduation. Based on these data, the background brightness is increased stepwise over 15 minutes from 0% to 30% (declination) and from 30% to 0% (declination). This optimizes energy consumption consistent with the natural light cycle and avoids abrupt changes in brightness.Movement speed dependent adaptation:The integrated microwave sensor (8) detects not only movements but also the approximate speed of the object (e.g. pedestrian vs. bicycle):• With slow movement, such as passersby, the brightness is increased to 60%.• In the case of rapid movement, such as of a bicycle, the brightness is controlled to 100% in order to ensure early visibility.Animal-friendly dimming:To minimize light pollution and protect wild animals, the system sequentially dims the brightness when inactive from 100% to 30% over a minute, rather than turning it off abruptly. This reduces stress for animals active at night.SOC and Weather-Based Control:With an SOC of more than 60%, a background brightness of 50% is set, which is controlled up to 100% when detecting movement. If the SOC falls below 30%, the basic brightness is reduced to 25%, the maximum brightness during movement remaining limited to 50%. In fog, the system automatically increases the background brightness to improve visibility, while in clear general-mid nights it reduces brightness.Schlechtwetterprophylaxe:In predicted bad weather periods (e.g. heavy rain or weather), the battery ( 9) charges preventively up to 100%, even if the SOC is already 80%, preferably 70%, in order to operate efficiently autonomously for as long as possible. At the same time, the basic brightness is reduced to 30% in order to achieve reliable illumination in conjunction with the greatest possible autarchia.Clustering Capability and Reliability:The lighting system allows networking of multiple luminaires into logical clusters, which typically consist of up to ten lamps. Within each cluster, luminaires are equipped with an LTE module ( 17) that function as master and backup luminaires. The master takes over the central task of data bundling and communicates with the cloud platform representative of the entire cluster. The remaining lamps in the cluster are connected to one another via a Bluetooth mesh network, which is based on ESP32 microcontrollers ( 13) and enables efficient local data transmission.If the primary master fails, the second LTE-capable light automatically assumes the role of the master. This failover mechanism ensures that communication with the cloud continues to be maintained and the cluster is functioning normally. However, should both LTE lights fail, the remaining lights in the cluster continue to operate autonomously. In this case, they rely on the last synchronized data reading to keep the illumination parameters consistent.The synchronization of the control data is effected dynamically: as soon as the state of charge (SOC) of a lamp changes by at least 5%, a synchronization is initiated. The master acquires the updated SOC data of all lamps in the cluster and transmits them to the cloud. This allows the cloud platform to adapt control commands, such as the reduction of the background brightness or other energy-efficient measures. This combination of LTE-based communication, Bluetooth mesh network and automatic failover mechanism ensures high failsafety and reliable functionality of the system under all conditions.Energy Delivery Function:The lighting system provides a flexible power delivery function that efficiently uses excess power once the battery state of charge (SOC) is above 70%, and weather conditions allow continuous solar power harvesting. In this state, the excess energy is either provided via an integrated charging station, for example for e-bikes or other small electrical devices, or used for supplying a WLAN hotspot. This function makes the system particularly attractive for urban and low-infrastructure areas, as it not only provides lighting, but at the same time provides additional services such as Internet access or charging facilities.In addition, the excess energy-provided it can be realized technically and infrastructureally-can be fed into the local power grid. This opens up the possibility of integrating the system into an existing energy network and actively contributing to the local energy supply. The feeding is effected via an energy output module which regulates the current flow and ensures that no overloading of the local network occurs.Control of this function is effected dynamically by the microcontroller (13) of the system, which decides on the basis of the SOC and the weather data how the surplus energy can be used most efficiently. If the SOC change is below 70%, the energy output is automatically stopped in order to ensure the autonomous operability of the lighting system. This intelligent control maximizes the efficiency of the system and allows for versatile use of solar energy - for both lighting and external applications.Access to TerminologyIn order to ensure that readers without any great technical knowledge can understand the invention, more complex terms are briefly explained below: 1. lithium iron phosphate battery (LiFePO4):A rechargeable battery (9) having high safety and long life. It is characterized by a high cycle stability and is less susceptible to thermal instability than conventional lithium-ion batteries.2. SOC (State of Charge):The state of charge of a battery in percent of its total capacity. An SOC of 100% means,the battery is fully charged while an SOC of 0% indicates that it is fully discharged.3. MPPT Charging Controller:A "maximum power point tracking" charging controller ( 10) optimizes the generation of energy from solar modules ( 5) by continuously ascertaining the point of maximum power and using it.4. Microwave sensor:A sensor (8) which detects movements by emitting and receiving microwaves. In this case, it measures changes in the frequency (Doppler effect) in order to detect movements precisely.5. NB-IoT / LTE / 4G:Communication standards for high-range and low-power wireless data transmission. They allow the system to connect to the cloud platform for control and analysis capabilities.6. OpenMeteo API:A programming interface (API) via which weather data such as temperature, degree of vaulting or precipitation can be retrieved. This data is used to dynamically adapt the lighting system to environmental conditions.7. Clustering ability:The ability of the system to crosslink a plurality of luminaires together and to centrally control them as a group ("cluster"). This enables coordinated control and increased fail-safe.List of reference characters1 Natural-grown Robinia wood pile 2 Adjusting mechanism 3 LED module 4 Battery compartment 5 Solar panel 6 Housing 7 Mounting bracket 8 Motion sensor 9 Battery 10 Charging controller 11 Battery monitoring sensor 12 Voltage converter 13 Microcontroller 14 Recesses for the plug-and-play LED groups 15 Recesses for the plug-and-play battery connections 16 Slightly protruding the solar panel beyond the housing 17 LTE / 4G module

Claims

Autonomous, solar-operated lighting system, comprising: a) a photovoltaic module (5) for converting solar energy into electrical energy, b) a rechargeable lithium iron phosphate battery (LiFePO 4) (9) for storing the generated energy, c) at least one dimmable LED luminaire (3) for lighting, d) a control unit with microcontroller (13) and integrated control software, e) a communication module (17) for wireless data transmission (NB-IoT, LTE or 4G), f) a sensor (11) for detecting the battery state of charge (SOC), g) a motion sensor (8) for detecting movements and determining the movement speed, h) a program logic for dynamically regulating the light intensity, wherein at least the parameters battery state of charge (SOC), detected movement speed and current and predicted weather data are evaluated, i) an energy output module for providing excess energy to external consumers or for feeding into the local power grid, characterized in that the lighting unit has a reduced basic brightness in the idle state and is controlled up to different brightness levels depending on the movement speed upon detection of movement, wherein animal-friendly transitions are additionally provided upon switching on and off, and the system charges the battery preventively up to the maximum value upon predicted poor weather in order to ensure extended autarchy.The lighting system of claim 1, characterized in that the system reduces the background brightness and limits the maximum brightness on movement to optimize energy efficiency at a battery state of charge (SOC) below a defined threshold (e.g. 30%).Lighting system according to one of the preceding claims, characterized in that, during predicted bad weather periods, the battery (9) is charged preventively up to 100% SOC, even if the SOC is already 80%, preferably 70%.Lighting system according to one of the preceding claims, characterized in that in the case of fog the basic brightness of the LED luminaire(s) (3) is automatically increased in order to improve the visibility.Lighting system according to any of the preceding claims, characterized in that in clear full-old nights the light intensity is automatically reduced to minimize light pollution.Lighting system according to one of the preceding claims, characterized in that, in the event of movement detection, a differentiation is made between slow (pedestrian) and fast (cyclist), different brightness levels (for example 60% or 100%) being set.Lighting system according to one of the preceding claims, characterized in that the system is installed on a natural-grown robinia wood pile (I) which is distinguished by high weathering resistance and ecological use of material.Lighting system according to one of the preceding claims, characterized in that excess energy is provided from an SOC of more than 70% for supplying external loads such as e-bike charging stations, WLAN hotspots or smart city components.Lighting system according to one of the preceding claims, characterized in that a plurality of units are networked to form a cluster, wherein at least one unit per cluster serves as a coordination unit with communication module (17), synchronizes the control data and provides an automatic failover mechanism in the event of failure of the coordination unit.Lighting system according to one of the preceding claims, characterized in that the housing (6) is connected to the carrier element (7) via a mechanical adjustment device (2), wherein the inclination of the luminaire relative to the ground can be individually adjusted in order to enable illumination which is optimum depending on location and to minimize light pollution.Lighting system according to one of the preceding claims, characterized in that the system is of modular construction and central components such as the solar module (5), the battery unit (9) and the LED modules (3) can be connected via plug-and-play connections and mounted or exchanged without a special tool.Lighting system according to claim 10, characterised in that the solar module (5) is mounted above the housing (6), protrudes beyond the housing (6) (16) and is screwed laterally, wherein the electrical connection is effected via a plug connection.Lighting system according to claim 10 or 11, characterised in that the battery (9) is accommodated in a separate compartment (4) and is connected by means of pluggable connections.Lighting system according to one of Claims 10 to 12, characterized in that a plurality of LED lighting modules (3) are arranged in groups and are each connected via separate plug connections, the connecting cables being guided into cutouts (14) (15) in the housing.Lighting system according to one of the preceding claims, characterized in that, when inactivity is detected, the brightness is not reduced abruptly, but rather stepwise within a defined period of time (for example 60 seconds), in order to minimize the environmental effect on animals active at night.

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