A Solar Powered Traffic Signal Systems are the traffic signals powered by solar consisting of cantilever and primary poles, signal heads, signal aspects, pedestrian aspects, count down timer, solar penal, controller (solar/grid charger: grid controller), battery charged by SPV panels/grid connection.

System Operation:-

The system should be of 14 hours operation and 10 hours blinking per day and must be designed to operated as Hybrid with solar and grid power. This should be designed to work for fully automatic operation with facility for manual operation. For auto-change-over from solar to grid and vise-versa provision should be there for Hybrid power source integrating 50% solar and 50% grid power, preference will be for solar energy only. In case the solar and grid both fails, system should be self sufficient for 10 hours operation from fully charged battery bank. There should be provision for charging through solar and grid both so that during sun-less days the grid power is utilized for charging.

  • The system operation mode should be UTO/ON/OFF BLINK.

  • The configuration will be of 2(two) sets of signal heads per road, one set of pedestrian signals per road and one count down timer per road.


The signals/signal aspects should be LET array, ultra bright type of lighting, suitable for daylight viewing. The visibility of the signals should be 500 meters and above. These signals aspects should be having enclosures of powder coated sheet metal with housing compatible to NEMA 12-IP.66 standards, designed for LED design life cycle of 10 years.

The signal heads required set of primary + secondary for each road should have provision for mounting both vertically and horizontally i.e. modular with Tilt and Rotate feature.

  • LED aspect size should be of 300 mm dia provided ultra bright LED in RED/AMBER & GREEN.

  • 3mm ultra bright REED LED timers should be provided as count down timer for residual time for green signal having 2-2.5 digits with letter height of 150 mm and should be visible from 100 meters or more and of 99 seconds duration.

  • Pedestrian/free left signals should be of composite Red/Green LED signal.

  • The DED LED should be of 620-635 nm wave length. The amber LED should be 584-600nm and the Green LED should be of 500-530 nm. The light intensity of the LEDs should be between 1650-6400 mcd. The size of LED should be 5 mm. The designed life of the LED should be 70,000 1,00,000 and the operating temperature 10-800C.

How a Solar Traffic Signal works:


Signal Controller:-

The signal controller should be 24 VDC, 20Watt, PLC/Cicro Controller based solid state switching device, designed, fully automatic with manual operation provisions, site programmable. Timing with on-site modification capability, compatible for Rs.232/Rs.422-442 and optional CP interface for 14 hours operation and 10 hours blinking per day. This should also be capable for synchronization, remote monitoring and control. The enclosure/housing should be or powder coated sheet metal dust and rain proof painted with moisture resistant fluorescent anti corrosive paint. The signals/system should be capable of meeting future up gradation and synchronization. The system up time should be greater than 98%.

Power System:-

The power source should be in multiples or solar photovoltaic modules of Multi Crystalline Silicon PV modules of 12V, 70-80 Wp (MNRE approved). The system voltage should be 24 VDC. Suitably designed for 50% contribution.

The Solar Charger should be suitably designed to perform at 24 Volts/15-30 Amperes, with a separate provision of Grid Battery Charger operating at 24V, 10Amps.

The Battery Bank:-

The Battery should be of sealed maintenance free, Lead Acid type, suitable for back up of `10 hours operation with maximum 80% depth of discharge. The Battery capacity should be 24V, 80-125 Ah or above.

Grid Input Power:-

The Grid input power should be single phase 50Hz 230 V Ac, suitable for grid charger 24V/10Amp.

Mounting Structure:-

Cantilever poles on main roads and vertical poles for side roads 6.2 meters and 5 meters above ground level respectively. To facilitate withstanding against heavy loads 400x400x1200mm and 400x400x900mm respectively with M 200 P.C. grouting below ground level excluding the length above ground level the poles should be provided with necessary lugs and grips.

The Poles should be of suitable thickness to withstand heavy wind and of 140mm M.S. pipe with suitable cantilever supports wherever necessary for bands, and should be painted with Moisture Resistant Fluorescent anti corrosive paint of VIOLA Blue colour with enamel finish.

Battery & Junction Boxes:-

The Battery Box and Junction Boxes of MS Sheets painted with moisture resistant fluorescent anti corrosive paint should be provided or, else these should be provided made of ABS plastic.

Control cable:-

Inter connecting cable and control cable should not be other than copper with PVC installation and of suitable size of 0.5-1.50 Sq mm the cores shall accordingly be provided taking the no. of channels into account. The cables in trenches shall be around with G.I. wire