Solar Powered Smart Pedestal Lighting System_Full Report

SRI MADHWA VADIRAJA INSTITUTE OF TECHNOLOGY AND MANAGEMENT, BANTAKAL-574115, UDUPI,

KARNATAKA.

Solar Powered Smart Pedestal Lighting System

An innovation to light up the rural India smartly (A TRIP project sanctioned by Vision Group on Science and

Technology(VGST) –Govt. of Karnataka)

Team Members

Pranav Rao

4MW12EC050

Electronics and Communication Engineering.

S R Dhanush

4MW12EC065


Ajesh

4MW12EC 002


Guide: Mr. Rajesh Nayak, Assistant Professor, Department of Electronics and Communication

Engineering, SMVITM, Bantakal.


VGST-TRIP Project Page 2

ABSTRACT

This project aims at harvesting the energy from renewable energy sources like sun

and to effectively use the harvested energy for the benefit of the remote villages

(villagers) facing serious power problems. The main aim of the project is to

provide “Smart Street Lighting system” powered with solar energy to assist

villagers during night time.



ACKNOWLEDGEMENTS

We are highly indebted to Sri Madhwa Vadiraja Institute of Technology and Management for

providing the necessary infrastructure and facilities. We sincerely express our deep sense of

gratitude to His Holiness Sri SriVishwavallabhaTheerthaSwamiji, Founder and President of our

college, Prof. Dr. Radhakrishna S. Aithal, Principal and Prof.Dr. BalachandraAchar, HOD,


We would like to express our gratitude towards Vision Group on Science and Technology

(VGST) for funding this project and members of Selco Solar Power Systems for their kind co-

operation and encouragement which helped us in completion of this project.

We have taken efforts in this project. However, it would not have been possible without the kind

support and help of many individuals especially Prof. Dr. Ravindra who showed us the right path

to proceed and Prof. (Dr). Nagaraj Rao who encouraged us venture into this opportunity, and our

project guide Mr. Rajesh Nayak. We would also like to thank Mr. Vignesh Kalathur whose ideas

and skills have helped us to complete our model.

Our thanks and appreciations also go to our classmates in developing the project and people who

have willingly helped me out with their abilities.



Contents 1. Introduction .............................................................................................................................................. 5

2. Background ............................................................................................................................................... 6

3. Solar Powered Smart Pedestal Lighting system ...................................................................................... 7

4. Function Description ................................................................................................................................. 8

5. Block Diagram ........................................................................................................................................... 8

Description of the Blocks ........................................................................................................................... 9

Solar Panel ................................................................................................................................................. 9

Dusk-Dawn Regulators (DDR) .................................................................................................................. 12

Motion Sensors ....................................................................................................................................... 13

Lead-acid batteries .................................................................................................................................. 16

LED Panel ................................................................................................................................................. 16

6. Power Consumption ............................................................................................................................... 18

7. Integration of the units into a System ................................................................................................... 19

8. Evaluation ............................................................................................................................................... 20

Project setup ........................................................................................................................................... 20

Conclusions .................................................................................................................................................. 23

Bibliography ................................................................................................................................................. 24



1. Introduction The energy consumption in entire world is increasing at the fastest rates due to population growth

and economic development and the availability of energy sources remains woefully constrained.

Resource augmentation and growth in energy supply has not kept pace with increasing demand

and, therefore, India continues to face serious energy shortages.

The project aims at harvesting the energy from renewable energy sources like sun and to

effectively use the harvested energy for the benefit of remote villages (villagers) facing the

serious power problems. The main aim of the project is to provide a “Smart Street Lighting

System” powered with solar energy to assist the villagers during night time. We use the word

“smart” because the system not only provide power to the street lights but also helps in detecting

the direction of movement of the pedestrian and helps him by means of illuminating the path of

movement till the near next street light. By integrating the entire street lights with Smart street

light system it is possible to systematically help the pedestrian to reach the destination in the

remote rural areas which are facing serious electric power supply problem. The same system can

also be used for the House lighting purpose as it works on the principle of sensing the thermal

signature of human body to switch the light, there by the system helps in saving the electric

power.



2. Background The key indicators of India’s energy problems include; Over 40 per cent of the households

(particularly rural areas) in India still do not have electricity, about a third of our total primary

energy supply to rural areas still comes from non-commercial sources (biomass, dung) and

currently India faces an enormous demand supply gap of about 15-25% energy shortage. Due to

shortage of the energy supply till today several villages have not facilitated with electricity and

even if provided, the supply of the electricity is limited to few hours in a day and are facing

serious problems due to unlimited power cuts.

During the day time we get enormous amount of light energy from sun and the problem for

pedestals are common during the night time. Though most of the streets are equipped with street

lights in each and every village areas but due to the uncontrolled power failures/power cut it is

becoming a serious problem for villagers to commute for irrigational field work during the night

time due to unlimited power cuts which indirectly affect the crop yield of the farmer. Such trends

often discourage the villagers taking up agriculture which is the backbone of our economy. It

also poses a serious threat to the villagers from physical hazards such as thieves, snakebites, etc.

Installation of street lights may seem a pleasant option but absence of electricity reducers their

presence to null. Hence the best option is to install solar powered street lights and moving a step

ahead, we designed this ‘Solar Powered Smart Pedestal Lighting System’.



3. Solar Powered Smart Pedestal Lighting system

The Smart Solar Street Light consists of motion sensors which detect the presence of pedestrians

in its proximity and the lights turn on which otherwise is ’off’. High power LEDs are used for

illumination. The system would derive the energy from the solar panel installed at the top of the

unit whose generated electricity is stored in Lead- Acid battery.

The ‘Solar powered Smart Street Lighting System’ is an integration of number of such units of

the smart street light which would be installed in the village such that the units could provide

continuous light to pedestrians at night assisting him to reach his destination. The above system

has two main advantages-

Reduces the wastage of harvestedenergy and hence can be deployed in regions with very

low sunlight also.

Simple design and hence easier maintenance.



4. Function Description The design basically includes three working modes:-

OFF mode: When there is enough natural light in the surrounding i.e. during the

daytime, the entire system is switched off and the batteries are charging.

Active mode: When the natural light drops below a certain level the system automatically

turns on and the motion sensors are powered.

ON mode: On the presence of pedestrians, the sensors turn the relays on which in turn

switches on the LED lights. These lights turns off after a fixed period of time.

5. Block Diagram



Description of the Blocks Each of the blockis described clearly in the following sections:

Solar Panel Solar panels are used to power the whole system. A solar panel (PV panel) is made of the natural

element, silicon, which becomes charged electrically when subjected to sun light. Solar panels

are directed at solar south in the northern hemisphere and solar north in the southern hemisphere

(these are slightly different than magnetic compass north-south directions) at an angle dictated by

the geographic location and latitude of where they are to be installed. Typically, the angle of the

solar array is set within a range of between site-latitude-plus 15 degrees and site-latitude-minus

15 degrees, depending on whether a slight winter or summer bias is desirable in the system.

Many solar arrays are placed at an angle equal to the site latitude with no bias for seasonal

periods.

This electrical charge is consolidated in the PV panel and directed to the output terminals to

produce low voltage (DirectCurrent) - usually 6 to 24 volts. The most common output is intended

for nominal 12 volts, with an effective output usually up to 17 volts. A 12 volt nominal output is

the reference voltage, but the operating voltage can be 17 volts or higher much like your car

alternator charges your 12 volt battery at well over 12 volts. So there's a difference between the

reference voltage and the actual operating voltage.

The intensity of the Sun's radiation changes with the hour of the day, time of the year and

weather conditions. To be able to make calculations in planning a system, the total amount of

solar radiation energy is expressed in hours of full sunlight per m², or Peak Sun Hours. This term,

Peak Sun Hours, represents the average amount of sun available per day throughout the year.

Fig. Two Solar Panel Connected in Series



The output of a solar panel is usually stated in watts, and the wattage is determined by

multiplying the rated voltage by the rated amperage. The formula for wattage is VOLTS times

AMPS equals WATTS. So for a 12 volt 60 watt solar panel measuring about 20 X 44 inches has

a rated voltage of 17.1 and a rated 3.5amperage.

VxA=W

17.1 volts times 3.5 amps equals 60 watts

Two solar panels 45 watts each would be connected in series combination. In an average the

solar panel would be receiving direct sunlight for period of 7 hours per day. So by simple

calculation we can find that on an average day we can store approximately 0.63 kWh of power

per day.

Figure: Two 45 Watt solar panels



Performance Measurement of the Solar Panel used:-



Dusk-Dawn Regulators (DDR)

It charges the battery during the day time and turns on the load at dusk. It turns off the load at

dawn. It not only charges the battery from solar panel in the optimum way using the fullest

power without much loss but maintains the SOC of the battery under charge. Input losses are

practically negligible due to high efficiency charging in shunt mode. Similarly battery loss in

load circuit is less than 3% making it better than 97% efficient. Its pulse-width-modulation

(PWM) keeps the battery in excellent SOC to have prolonged life of battery.

FEATURES:

Automatic dusk to dawn operation.

Suitable to drive CFL or LED lights.

Day time consumption < 1mA.

True indication of battery charging.

Battery low indication.

Over load protection and indication. Reset switch provided.



Figure: Dusk-Dawn Regulators

Motion Sensors

A standard PIR sensor is used as the movement detector. The 4 sensors interfaces to the PICAXE

(IC1) on input 1, input 2 input3, input4. These pins are pulled low via isolation diodes D2, D3,



D4, D5 and the normally open (NO) output of the sensor whenever movement is detected. It can

also be pulled low by transistor Q1, Q2, Q3, Q4which acts as a simple inverters for sensors with

normally closed (NC) outputs (Fig 3).

So that the lights aren’t needlessly switched on during the day, a light-dependent resistor (LDR)

is used as an ambient light sensor. Together with a 100kΩ resistor, the LDR forms a simple

voltage divider, which converts its changing resistance to a changing voltage at the micro’s

analog input (pin 7). As light falling on the sensor decreases, its resistance increases, resulting in

less voltage at the analog input. Below a preprogrammed threshold voltage, it is assumed to be

night-time.



The observed range of the PIR sensors is 6-7 metres.

Figure: Circuitry for receiving the sensor output (Four units for each of the PIR module)

Figure: One of the PIR sensor connected



Lead-acid batteries Lead-acid batteries are the most common in PV systems because their initial cost is lower and

because they are readily available nearly everywhere in the world. There are many different sizes

and designs of lead-acid batteries, but the most important designation is that they are deep cycle

batteries. Lead-acid batteries are available in both wet-cell (requires maintenance) and sealed no-

maintenance versions. AGM and Gel-cell deep-cycle batteries are also popular because they are

maintenance free and they last a lot longer. The Deep Cycle batteries used are designed to be

discharged and then re-charged hundreds or thousands of times.

The battery should have sufficient amp hour capacity to supply needed power during the longest

expected period "no sun" or extremely cloudy conditions. A lead-acid battery should be sized at

least 20% larger than this amount.

We used a 60Ah battery for the design. The wattage of the LED panel is roughly 30 Watts

(considering all the subunits and the sensor units).

On a good sunny day, 0.63 kWh of power can be stored which could last for up to 4 days with

little sunlight.

LED Panel

LED panel is built in consists of sub-units within it, each inclined at 30 degrees towards the path

it is illuminating. Assuming the unit is fixed in a junction of four roads, we have designed the

panel as shown in the above figure. 3 W LEDs are used in the design.



LED bulbs in general are brighter than incandescent lamps and CFLs of the same wattage. A 3-

watt LED bulb may produce anywhere between 240 to 320 lumens of illumination. Lumens is a

measure of light. ‘Lumens per watt’ is the measure to identify how much light is produced for the

energy or wattage drawn. Accordingly, the minimum efficiency of a 3 Watt LED bulb will be 80

lumens/watt. A 20 Watt halogen bulb on the other hand may produce 350 lumens of energy on

average, with an efficiency of 17 lumens per watt used.

3 Watt rated LED bulbs consume very low power, usually less than 4 watts. A single 3 Watt

LED bulb can be equivalent to a 30 Watt fluorescent lamp. It is possible to choose between white

light LED bulbs, warm light LED bulbs and colored light. White light bulbs can last more than

50,000 hours. On the other hand colored LEDs can last twice as long at more than 100,000 hours.



6. Power Consumption Two solar panels 45 watts each would be connected in series combination. In an average the solar

panel would be receiving direct sunlight for period of 7 hours per day. Hence using the equation

Power = (power in wattage) × (hours)/1000

So by simple calculation we can find that on an average day we can store approximately 0.63 kWh

of power per day.

A set of ten LEDs will be used which will require 0.36 kWh of power for twelve hours .This

value is compatible with the designed solar power unit, leaving enough power for the

microcontroller unit and required backup.



7. Integration of the units into a System So we have seen the working and specifications in the previous section for one unit of a Smart

Solar Street Light. Let us abbreviate it as SLU (Street Lighting Unit). Number of SLUs are

installed around the village along the street with an average distance of 12 meters between each

unit. Thus a pedestrian is always within the range of the SLU which illuminates his path.

The path of a person walking at night is continuously illuminated by one or the SLU. He gets a

feeling that the light is following him!

SLU

SLU

SLU

SLU



8. Evaluation Implementing and analyzing the prototype we built, we found that the design could be largely

efficient in street lighting in not only villages but also any other place as well. Also for the

specifications, two Street Lighting units could be powered. Hence we found the system really

energy efficient. The following listing shows the advantages of the system:-

Reduced battery capacity and solar panel wattage

Reduced cost

Low maintenance cost

Simple operation

Suitable for regions with limited sunlight also

One shortcoming of our design is we underestimated the amount of power required to power the

system. Since the lights would be turned on an average of 3 hours per night (which we calculated

for 10 hours per night in the initial stages), the specifications of the solar panel and the lead-acid

storage battery is much high compared to the actual requirement which cost us more.

Project setup

Figure: Demo model for a single unit of lighting system



Figure: Demo model for the system installed in a village (Where the mini robot simulates movement of

pedestrians)





Conclusions

The successful implementation of the project would help the remote areas which

are facing severe Power supply problems. The lighting system uses LED’s and

hence the power consumed will be much less compared with the conventional

lighting systems. Further if similar lighting systems are implemented for normal

street lighting by the government, we would be saving a great amount of electricity

which otherwise is just wasted…



Bibliography

[1] www.main.org/polycosmos/glxywest/vimanas.htm - Indian Flying Machines

[2] www.electronicsforyou.comI.

[3] http://www.triplepundit.com/2011/08/solar-farming-potential-india/- Solar Farming

[4] http://en.wikipedia.org/wiki/Solar_cell

[5] http://www.planetarypower.com.au/solar_panels.htm

[6] Element14 – to look up devices, ICs

[7] Physics of Solar Cells- A Text for Undergraduates, J Nelson

Solar Powered Smart Pedestal Lighting System_Full Report

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