1. 1 Renewable Energy and LED Lamp Post & Energy Center Prof. Eric Cheng Dept. of EE The HK PolyU

2. Why LED lamp Long life time Future lighting More method to control and display Low voltage DC Safer Work well with battery

3. Prototype of Solar LED Lighting and Battery Charging system

4. Solar LED street light is a big contribution to energy savings Before (HPS)After (LED) Solar energy is environmental energy source. LED light has many advantages:  Energy saving, low power consumption  High efficacy(>70lm/w)  Long life span(>50000hours)  Controllable light level Before and after photos of the lighting on the street

5. Solar LED street light and battery charging system block diagram

6. Working Mode of Overall System At daytime, solar panel tracks sunlight to absorb maximum solar energy At nighttime, reset stepper motor for tomorrow’s tracking sunlight and start LED lighting system. At dusk time and early morning, tracking sunlight and LED lighting stop operating. Converter also stops operating. Solar street light system is at idle state

7. Equipment for Lightings Spectrum of a LEDLamp Complete Analysis System

8. DC/DC converter Charging mode At daytime, Solar panel absorbs sunlight and its output voltage is higher than battery’s voltage. M1 turns off to disconnect LED with converter. Converter works at charging mode. LED lighting mode At nighttime, Solar panel has no energy stored in it.M1 turn on to connect LED with converter. Converter works at LED lighting mode. Converter boost battery voltage to LED lighting voltage needed.

9. Two tracking system Mechanical tracking system -Solar panel tracking sunlight Solar panel tracks sunlight step by step with stepper motor to absorb maximum solar energy Electronic tracking system -Maximum power point tracking Varies the electrical operating point of the solar panel so that the solar panel is able to deliver maximum available power

10. Main Applications Streets and highways Parking sites Railroad lines Community areas Rural towns Schools

11. Energy center The energy collected from the Solar can also provide additional power source. It act as an energy center to users We can use the additional power unit for computer, phone charger

12. System control

13. Thank You!