The off-grid streetlamp design simplifies solar lighting development with power tracking, flexible configurations, and performance adjustments.
A Solar Power Maximum Power Point Tracking (MPPT) Controller is a crucial component in optimizing the performance of solar power systems. It ensures that solar panels operate at their maximum power point (MPP), generating the most energy. As sunlight and environmental conditions vary throughout the day, the MPPT controller continuously adjusts the system’s voltage and current to match the optimal operating conditions. This maximizes energy production, improves system efficiency, and helps make the most of available solar energy. By maintaining optimal performance, MPPT controllers contribute to longer system lifespans and offer cost-effective solutions for renewable energy generation. The Solar Power MPPT Controller reference design from Onsemi simplifies the design process.
The off-grid solar streetlamp reference design provides insights for design engineers developing solar-powered lighting solutions. The system includes LEDs, a lead-acid battery, a solar controller, and a solar panel. The solar panel captures sunlight and converts it into electrical energy. However, sunlight intensity varies throughout the day due to cloud cover, the sun’s angle, seasonal changes, and reflections from surrounding surfaces. For example, a solar panel rated for 30W peak power may produce only 24W at midday and 6W in the evening. The panel’s voltage output is adjustable, typically ranging from 20V to 48V, depending on the configuration of the solar cells.
The system currently consumes less than 2mA of the battery, reducing energy usage. It includes maximum power tracking with an error margin of less than 5%, optimizing energy efficiency. The system can charge up to four batteries in series or parallel, providing flexibility in battery configurations. It is compatible with solar panels from 10W to 30W, allowing engineers to scale the design for different power needs. Additionally, it can be used in parallel with other systems, enabling integration and expansion.
A 30W solar controller in this design helps evaluate the maximum error in determining the peak power point. By connecting the controller to a 30W solar panel and collecting I-V curve data using a resistive load, engineers can confirm that the error in locating the maximum power point remains under 5%.
The control scheme is designed to detect and adapt to both static and dynamic conditions. For instance, as trees grow or shadows move across the panel due to wind, the system adjusts in real-time, ensuring the solar panel operates at its maximum power point. This responsiveness, such as handling rapid changes in sunlight exposure within less than 6 seconds, enhances the system’s performance in real-world conditions. Engineers can use this reference design to create off-grid solar lighting systems with energy efficiency and reliable performance in variable environments.
Onsemi has tested this reference design. It comes with a bill of materials (BOM), schematics, assembly drawing, printed circuit board (PCB) layout, and more. The company’s website has additional data about the reference design. To read more about this reference design, click here.
