TECHNOCOMMERCIAL FEASIBILITY STUDY OF EXISTING STREET LIGHTING SYSTEMS BY SOLAR IN BHUBANESWAR Abstract:- There are many ways to save energy. Lighting is one such area that offers many opportunities for improving the energy efficiency. The electricity consumption for lighting alone is estimated to be 19% of the total global electricity consumption. Reducing electricity consumption for lighting by 40% can lead to major reduction in the total electricity consumption for lighting from 19% to 11%.In this paper the traditional lights are replaced by LEDs and the consumption source is replaced by solar from thermal. For efficient use of solar street lighting system the lights can be replaced by either AC LED or DC LED. The street lights operation is required during the non sunshine hours. This necessitates the use of battery in PV system. Whenever a battery is used, a charge controller is also used to ensure long battery life. This paper shows a step by step manual calculation for a solar street light in an urban area named Bhubaneswar. Then the technical, economical and environmental impact of these replacements is being studied.. Keywords: LED, system voltage,solar panel, DOD, solar radation I. Introduction Reducing electricity consumption for lighting by 40% can lead to major reduction in the total electricity consumption for lighting from 19% to 11%. This has many advantages. The energy saving will lead to drop off the need for the establishment of new power plants thereby minimizing carbon emission and hence global warming. Electric Street Lights are big consumers of energy, costing millions to cities and municipalities around the world. Solar Street Lights were initially used mainly in Third World SAMPURNA PANDA Assistant Professor,ITM University Sampurnapanda1412@gmail.com countries, in remote areas or where electricity is not always available or supply unreliable. Providing street lighting is one the most important and expensive responsibilities of a city: Lighting can account for 10 38% of the total energy bill in typical cities worldwide (NYCGP 2009). Street lighting is a particularly critical concern for public authorities in developing countries because of its strategic importance for economic and social stability. Inefficient lighting wastes significant financial resources each year, and poor lighting creates unsafe conditions. Energy efficient technologies and design can cut street lighting costs dramatically (often by 25-60%); these savings can eliminate or reduce the need for new generating plants and provide the capital for alternative energy solutions for populations in remote areas. These cost savings can also enable municipalities to expand street lighting to additional areas, increasing access to lighting in low-income and other underserved areas. In addition, improvements in lighting quality and expansion in services can improve safety conditions for both vehicle traffic and pedestrians. II. Present Scenario of Street Lights in Bhubaneswar A survey of street lights present in Bhubaneswar and meeting with the City Engineer of Bhubaneswar Municipal Corporation (BMC) results approx 30,000 numbers of street lights & 30 high mast lights in BBSR. As per the data collected mainly 5types of lamps are used in Bhubaneswar which are fluorescent lamp, metal halide lamp, sodium vapor lamp, CFL and high mast lights. ISSN 2394-0573 All Rights Reserved 2016 IJEETE Page 209
A. Evaluation of Yearly consumption of all the street lights Table 1- Annual consumption of streetlights Lamp type Yearly consumption fluorescent lamp 2190000kwh/year (10000 nos,50w) Metal halide lamp 8760000kwh/yr (10000 nos,200w) sodium vapour 8760000kwh/yr lamp (10000 nos,200w) high mast lights (30 459900kwh/year nos,700 5W) Total 20169900kwh/year B.Environmental impact & Economical Scenario Calculation results requirement of 12101940kg of coal for generation of above mentioned power with 18556308 kg emission CO 2 per year..only the operating cost of the street lights isrs181,529,100/year (considering Rs9/unit). III. Reduction of CO 2 emission by utilization of Solar power and by replacement of lights by AC &DC LED The street lights operation is required during the non sunshine hours. This necessitates the use of battery in PV system. Whenever a battery is used, a charge controller is also used to ensure long battery life. All the bulbs used for street lighting purpose are AC bulbs, which require an inverter in the system to convert DC into AC. An MPPT circuit can also be used in the system to optimize the PV source utilization. Therefore, PV system design involves the determination of the size and capacity of various components like PV panels, inverters, batteries, charge controllers etc. The energy flow in the system can be well known from the energy flow diagram Fig1 which is shown below. Fig1. working of proposed solar street lighting system The system design proceeds in the reverse direction of energy flow. Thus, first the loads and their requirements (power, hours of operation, energy requirement etc.) are identified. Overall design of this configuration can be divided into three steps: Step1.Determination of load (in watt-hour),power converter rating and the system voltage requirement. Step2.Determination of the Battery size (their number, capacity, voltage and Ah ratings). Step3.Determination of PV panel size (their number, capacity, voltage and current ratings) Fig2.Energy flow in the proposed solar street lighting system ISSN 2394-0573 All Rights Reserved 2016 IJEETE Page 210
IV. Evaluation for 30Watt DC LED: Daily energy used by one street light bulb=360wh(operating hour 12hrs) System voltage: The voltage and current in a PV system after the inverter are AC but before the inverter, from PV module to inverter input, the voltage and current are DC. Typically the terminal voltage of batteries used in a PV system is 12 V. Therefore the PV system voltage should be 12 V. If higher PV system voltage is required then it should be in the multiples of 12V ie12v, 24V, 36V, 48V etc. Higher PV system voltage should be chosen to minimize the current carried by the cables so as the power losses and voltage drop. Sizing of Batteries: In solar PV Deep discharge batteries are used with DOD in the range of 60% to 80%.Let us consider the batteries of 12V,100Ah are used with DOD 70%.This means that out of 100Ah battery capacity only 100*0.7=70% Ah is the usable capacity. Then, theenergy that should be supplied by the PV panels at the input of the controller circuit should be = 470.57Wh. About 470.57Wh energy should be generated by the PV panels every day. Solar radiation, Capacity and No of panels: PV panels need to supply the energy to the battery bank at the specified system voltage. Total Ah generated by the PV panels should be, =19.6Ah or =39.21Ah Solar PV modules power capacity is measured at an input solar radiation of 1000W/m2.In Odisha,peak equivalent sunshine hours vary between 5h to 7h,corresponding to 5000W/m 2 to 7000W/m 2 - day. Let us consider in Odisha, we have 6h equivalent to peak sunshine hours. The total amperes that should be produced by the PV modules can be calculated as: or The energy that needs to be supplied by the battery is 360Wh. The required charge capacity of the battery= or Now, the no of batteries should be used= or Sizing of PV Modules: The daily energy supplied by the battery bank (battery output to the load) is 360Wh.Normally battery efficiency is between 80% and 90%.Let us consider efficiency of the battery is 85%.So, energy supplied at the input of the battery terminal should be, =423.52Wh The energy to the input terminal of the battery bank is supplied through controller electronics (charge controller and MPPT).The efficiency of control circuit is generally high. Let us consider the efficiency of the controller circuit is 90%. A typical peak power rating, Wp (maximum power the module will produce under 1000W/m2) of modules varies from 5Wp to 300Wp.As the street lights are of 30 watt, Let us consider 30Wp modules will be used. A manufacturer s datasheet provides the current and voltage ratings as follows: Table 2-Manufacturer s datasheet for 30W polycrystalline solar panel. Table 2- A manufacturer s datasheet for 30W Polycrystalline solar panel Open circuit voltage: 21.6V Optimum operating 17.2V voltage Short circuit current 1.93A Optimum operating 1.74A current Now, if one module provides 1,74A amount of current then, the no of modules required to produce 5.85A or 11.71A current are ISSN 2394-0573 All Rights Reserved 2016 IJEETE Page 211
=1.87 or =3.75 So, for 12V system voltage 4no of modules are required and for 24V system voltage 2nos of modules are required. These modules should be connected in parallel. In the similar manner for 30watt AC LED an inverter is placed in between battery and load. The parameters and cost can be evaluated. V. Cost comparison for designing solar street lighting system replacement of incandescent bulb by DC & AC LED: Various parameters for the equipments used for replacement of conventional energy source by solar and traditional light by LEDs are evaluated for system voltage 24V &12V.The total cost is being calculated considering the standard cost in INR for both AC &DC LEDs. Table 3-cost calculation for AC&DC LEDs for 24V&12V It can be observed from the above calculation that keeping the system voltage maximum reduces the no.of panels &hence the cost. Keeping the voltage maximum also gives the advantage of lower line loss. VI. Analysis by using PV SYST software: ISSN 2394-0573 All Rights Reserved 2016 IJEETE Page 212
[5] E. Kaplani Design and performance VII. Summary considerations in stand alone PV powered Design of Solar Street Light System without Telecommunication Systems 2012 IEEE. replacing the bulbs will cost Rs 1,500,200,000/- [6] P. G. Nikhil, D. Subhakar Sizing and Parametric.Design of Solar Street Light System Replacement Analysis of a Stand-Alone Photovoltaic Power by DC LED Rs 1,020,800,000/- Plant, IEEE journal of photovoltaics, vol. 3, no. 2,.Design of Solar street lighting system with AC april 2013. LED will cost Rs 1,161,550,000/-.Solar system without replacing the bulbs is the [7] Mokhtar Ali1, Mohamed Orabi1, Emad most expensive method.solar street lighting system Abdelkarim1, Jaber A. Abu Qahouq 2 and Abdelali is the most efficient one because of the following El Aroudi Design and Development of Energyreasons.As it can be integrated with the Free Solar Street LED Light System 2012 IEEE. conventional power(grid) if required.the payback period is about (11-13) years.replacement of AC LED is cheaper than the DC LED. VIII. References List and number all bibliographical references in 12-point Times New Roman, single-spaced with single-line interlining spacing, at the end of your paper. When referenced in the text, enclose the citation number in square brackets, for example [1]. Where appropriate, include the name(s) of editors of referenced books. Unpublished articles or private communications should not be given in the reference list. Examples are given below for illustrations: References Sample in given below: [1] Safaa Alzubaidi, and Prashant Kumar Soori Study on Energy Efficient Street Lighting System Design 2012 IEEE International Power Engineering and Optimization Conference (PEOCO2012), Melaka, Malaysia: 6-7 June 2012. [2]M. A. Dalla Costa, L. Schuch, L. Michels, C. Rech, J. R. Pinheiro and G. H. Costa Autonomous Street Lighting System based on Solar Energy and LEDs 2010 IEEE. [3] IEEE JOURNAL OF PHOTOVOLTAICS, VOL. 3, NO. 2, APRIL 2013 Sizing and Parametric Analysis of a Stand-AlonePhotovoltaic Power Plant BY P. G. Nikhil, Member, IEEE, and D. Subhakar [4] Rahnuma Rifat Chowdhuryy, Muhammad Salahuddin Kabiry and Muhammad Abdullah Arafat Electrification of Streets of Dhaka City Using Smart Solar System 2013 IEEE [8] M. A. Dalla Costa, L. Schuch, L. Michels, C. Rech, J. R. Pinheiro and G. H. Costa Autonomous Street Lighting System based on Solar Energy and LEDs 2010 IEEE. Journals Parkvall, S., Astely, D., The Evolution of LTE towards IMT-Advanced. Journal of communications, Vol. 4, No. 3, 2009, pp: 154-164. Conferences Kumar, A. (2010). LTE-Advanced: 3GPP Evolution path towards 4G. Proceedings National Conference on Advances in Video, Cyber Learning and Electronics 2010 (ADVICE-2010), 18th-19th Feb, NITTTR, Chandigarh. pp: 166. Books Ergen, M., Mobile Broadband: Including WiMAX and LTE. Springer, USA, 2009. Website 3gamericas (2010). 3GPP Mobile innovation path to 4G: Release-9, Release-10 and Beyond: HSPA+, SAE/LTE and LTE-Advanced. [Online]. Available: http://www.3gamericas.org/index.cfm?fuseaction= page§ionid=334 AUTHOR S BIBLOGRAPHY Ms Sampurna Panda received her MTech degree in in the branch of Electrical Engineering in Power &Energy Specialisation in 2014.Presently she is working as an Assistant Professor in the department of Electrical Engineering in ITM Universe,Gwalior. ISSN 2394-0573 All Rights Reserved 2016 IJEETE Page 213