Green Solutions for Telecom Towers

 
 
Green Solutions for Telecom Towers
Green Solutions for Telecom Towers: Part II
        Solar Photovoltaic Applications



        Essential Energy India Pvt Limited

        July 2013




© 2013 Essential Energy India Private Limited
Contents

         1       INTRODUCTION                                                                               3

         2       SOLAR PHOTOVOLTAIC TECHNOLOGY (SPV) OVERVIEW                                               3
         2.1     Solar photovoltaic applications                                                            4
         2.2     Components of solar photovoltaic systems                                                   4
         2.3     Efficiency of solar photovoltaic panels                                                    5
         2.4     Geographic considerations for photovoltaic applications                                    6
         2.5     Advantages and challenges of solar photovoltaic technology                                 7

         3       SOLAR PHOTOVOLTAIC SOLUTIONS FOR TELECOM TOWERS                                             7
         3.1     Solution design considerations                                                              9
         3.2     Opportunities and challenges of moving to solar technology in the India telecom industry    9
         3.3     Government initiatives                                                                     11
         3.4     Green energy mandate for telecom towers                                                    12

         4       CASE STUDIES                                                                               12
         4.1     Case study 1                                                                               13
                       4.1.1    Site location                                                               13
                       4.1.2    Site description                                                            13
                       4.1.3    Site economics                                                              15
         4.2     Case study 2                                                                               17
                       4.2.1    Site location                                                               17
                       4.2.2    Site description                                                            17
                       4.2.3    Site economics                                                              19
         4.3     Challenges on the ground                                                                   20

         5       FUTURE OF SOLAR PHOTOVOLTAIC TECHNOLOGY FOR TELECOM                                        21




© 2013 Essential Energy India Private Limited
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1       Introduction
         Energy saving is a key sustainability focus for the Indian telecom industry today. This is especially true in
                                                                                                                        1
         rural areas where energy consumption contributes to 70% of the total network operating cost . In urban
                                                                                                     2
         areas, the energy cost for network operation ranges between 15-30% . This expenditure on energy as a
         result of the lack of grid availability highlights a potential barrier to telecom industry growth, especially
         regarding the expansion of rural teledensity which sits at 40.81% compared to teledensity in urban areas of
                      3
         146.15% .

         It is estimated that in India almost 70% of telecom towers are located in areas with more than eight hours of
                                                                                        4
         grid outage and almost 20% are located in off-grid areas . This uncertainty in power availability has
         compelled infrastructure providers to use diesel generators to ensure a continuous supply of power. Annually
         more than 2.6 billion litres of diesel are consumed to operate telecom towers, resulting in the emission of 7
                                                    5
         million metric tonnes of CO2                .   Given the deregulation of diesel prices and the need to reduce carbon
         emissions, it has become imperative for the industry to evaluate all alternative options in order to improve
         network operation and to reduce energy costs. Several efforts have been made to optimise energy costs,
         such as converting indoor base transceiver stations (BTS) to outdoor ones in order to eliminate air
         conditioning on site, installing energy-efficient equipment and also using clean energy sources to power the
         sites. Among them, using clean energy sources for power has the potential to resolve the three key needs of
         the telecom industry, namely: reduction in diesel usage; expansion of telecom infrastructure to off-grid areas;
         and reduction in carbon emissions. Clean-energy technologies are well supported by the Indian
                                                6
         Government’s subsidy policy . While clean energy technologies such as solar photovoltaic, wind turbines,
         biomass power and fuel cells have undergone trials at telecom sites, the majority of these trials have been
         with solar photovoltaic technology.

         This white paper discusses two real-time telecom tower sites using solar photovoltaic technology. The
         discussion includes an overview of the solution configuration and the economic case which includes OPEX
         comparisons before and after the deployment of the solar photovoltaic solution. The challenges for                     large-
         scale, on ground adoption are also evaluated.


         2       Solar Photovoltaic Technology (SPV) Overview
         Solar photovoltaic technology uses the light (photons) from the sun to produce DC electricity. As shown in
         figure 1, a photovoltaic cell is a light-sensitive semiconductor device which, when exposed to sunlight,
         releases electrons to produce DC current.



         1
             Adoption of Green Technology and Safety of Wireless Network by Milan Jain (Sr. Research Eng. – Converged
         Network, TRAI)
         2
             Adoption of Green Technology and Safety of Wireless Network by Milan Jain (Sr. Research Eng. – Converged
         Network, TRAI)
         3
             http://www.indiatelecomonline.com/topics/telecom-statistics/
         4
          http://www.gsma.com/mobilefordevelopment/wp-content/uploads/2012/05/Energy-for-the-Telecom-Towers-India-Market-Sizing-and-
         Forecasting-September-2010.pdf
         5
             Assumption – 2.1 litres. Diesel usage per hour and 8 hours of outage per day for 4,25,000 towers
         6
             http://www.solar-apps.com/Revised-Capital-Subsidy-and-Benchmark-cost-of-the-SPV-system.pdf


© 2013 Essential Energy India Private Limited
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Figure 1: Electricity generation in a solar photovoltaic cell




              nSilicon


                                        Electron flow

                                                                                        Sunlight




                                        Hole Flow
                                                                                      Solar Photovoltaic Panel

            pSilicon




         2.1 Solar photovoltaic applications

         Solar photovoltaic technology can be used as either a stand-alone, grid-connected or hybrid solution. The
         table below summarises the description of each type of application.

         Table 1: Three types of solar photovoltaic applications

          Solar photovoltaic applications               Description

          Stand-alone                                   This type of application requires the equivalent level of backup energy
                                                        storage to ensure power supply when sunshine is unavailable.

          Grid-connected                                In this application, energy is fed back from the photovoltaic module to
                                                        the grid.

          Hybrid                                        This is a combination of photovoltaic arrays and other energy sources
                                                        such as hybrids with wind turbines, biomass power, fuel cells and
                                                        diesel generators.


         2.2 Components of solar photovoltaic systems

         Solar photovoltaic cells, modules, panels, strings and arrays

         Solar photovoltaic cells are the building blocks of a solar photovoltaic system. Each photovoltaic cell circuit
         is packaged in a protective laminate to avoid moisture and corrosion.

         Solar photovoltaic modules consist of photovoltaic cell circuits and are connected in series and/or parallel
         to produce the required currents.

         Solar photovoltaic panels are the assembly of modules and are wired in series to form an installable unit.

         A number of panels are connected in series and are termed as a solar photovoltaic string.




© 2013 Essential Energy India Private Limited
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Solar photovoltaic arrays are a group of strings which form the complete power generation unit. Figure 2
         illustrates a solar cell, module, array and string structure.
                                                            7
         Figure 2: Structure of a photovoltaic system


                  Solar Cell


              Solar Module




                Solar Panel



              Solar String



             Solar Array

                                                                                                  Solar Photovoltaic Fuses




         Charge controller

         A charge controller regulates the voltage and current output from the solar panels as required by the battery
         and the load. It also keeps the batteries protected from overcharging and discharging.

         Battery bank

         The battery bank is used as storage providing the source of power during non-sunshine hours. Battery
         capacity is measured in Ampere-hours (Ah) at a constant discharge rate. A wide range of batteries can be
         used in solar photovoltaic configurations. Lead-acid and valve-regulated lead-acid (VRLA) gel batteries are
         most commonly used across telecom sites in India.


         2.3 Efficiency of solar photovoltaic panels

         The efficiency of a solar photovoltaic system varies and depends on the grade of the photovoltaic material
         used. The table below summarises the various types of solar photovoltaic materials and their respective
         efficiencies.
                                                                                                  8
         Table 2: Current range of efficiencies for different solar photovoltaic technologies

                           Wafer-based c-Si                                                Thin films

             Single               Multi                  Amorphous Silicon (a- Cadmium-Telluride                Copper-Indium-Diselenide
             Crystalline          Crystalline            Si); Micro-morph      (CdTe)                           (CIS) / Copper-Indium-
             (sc-Si)              (mc-Si)                Silicon (a-Si/μc-Si)                                   Gallium- Diselenide
                                                                                                                (CIGS)
             14-20%               13-15%                 6-9%                          9-11%                    10-12%

         7
             http://www1.cooperbussmann.com/pdf/9df1f7ec-8c62-4210-8cf8-9504927394f0.pdf
         8
             http://www.iea.org/publications/freepublications/publication/pv_roadmap.pdf


© 2013 Essential Energy India Private Limited
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2.4 Geographic considerations for photovoltaic applications

         Geographic parameters including daily average energy incidents, the duration and availability of sunshine
         and also solar power density across different geographic locations, influence the scope of solar photovoltaic
         deployment. Table 3 provides facts on solar radiation in India.

                                                                                          9
         Table 3: Geographic considerations of solar photovoltaic applications in India

             Parameters                                                                       Availabilities

             Daily average energy incidents                                                   4-7kWhr/m2

             Solar power density across India                                                 See solar map of India (figure 3)

             Duration of quality sunshine per day                                             Approximately 5 hours

             Number of days with quality sunshine                                             300

         The figure below shows the solar power density across India which maps the performance and deployment
         feasibility of solar photovoltaic solution

                                                    10,11
         Figure 3: Solar power density in India




         9
             http://en.wikipedia.org/wiki/Solar_power_in_India
         10
              http://en.wikipedia.org/wiki/File:Solar_Resource_Map_of_India.png
         11
              Map presents annual average of solar power density


© 2013 Essential Energy India Private Limited
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2.5 Advantages and challenges of solar photovoltaic technology

         Solar photovoltaic technology has some limitations which make its mass adoption challenging. These include
         high initial levels of capital investment, the requirement for large deployment areas, dependency on sunshine
         availability and configuration of storage capacity. Table 4 provides a broad overview of some of the basic
         advantages and challenges of solar photovoltaic applications.

         Table 4: Advantages and challenges of solar photovoltaic technology

          Parameters                               Advantages                                    Challenges

          Emissions                                Zero                                          None

          Space requirement                        None                                          Footprint requirement @10 square
                                                                                                 meter/kW.

          CAPEX                                    Recent drop in panel price                    Requires high storage capacity, hence
                                                   due to mass manufacturing and                 the additional battery cost increases
                                                   technology innovation                         the CAPEX.

          OPEX                                     No fuel required                              Regular panel cleaning is required to
                                                                                                 maintain optimum efficiency.

          Sunshine availability                    Average 300 days annually                     Some geographic locations in India
                                                                                                 have a prolonged monsoon season
                                                                                                 and     hence   less    availability   of
                                                                                                 sunshine.

          Solution configuration                   Easily integrated into                        Intermittent    sunshine     availability
                                                   hybrid solution                               requires    equipment automation to
                                                                                                 optimise solar photovoltaic usage. A
                                                                                                 higher capacity solution leads to a
                                                                                                 higher CAPEX investment.

          Storage                                  Enough sunshine to charge the                 High battery capacity is required in
                                                   battery in high solar density (4-             areas with less solar power density
                                                               2                                                    2
                                                   7kWh/m ) areas                                (less than 4 kWh/m ).



         3        Solar Photovoltaic Solutions for Telecom Towers
         Enabling distributed power generation and emission-free operation makes solar photovoltaic technology a
         desired option for backup power. However, the dependency on sunshine and the average space requirement
                                                          12
         of 10 square metres for a 1kWp panel limits the scope of deployment.

         In recent trials, the two types of applications deployed at telecom tower sites are stand-alone and hybrid
         solar photovoltaic. The application types were chosen based on the site load profile, grid outage scenarios,


         12
              Solar Opportunities in Telecom by Sai Ram Prasad, CTO, Bharti Infratel, Solar Directory 2012


© 2013 Essential Energy India Private Limited
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space availability at the site and other configuration aspects including average sunshine availability
         throughout the trial and the power storage configuration for non-sunshine hours.

         The illustration in figure 4 describes the stand-alone system and figure 5 details the hybrid application using
         solar photovoltaic technology. Hybrid applications can be developed by combining solar photovoltaic
         technology with various energy sources such as wind turbines, biomass gasifiers, fuel cells and diesel
         generators. Using an augmented battery bank is not considered to be a hybrid solution; instead it is a part of
         the solar photovoltaic solution.

         Figure 4: Stand-alone solar photovoltaic application




                                       Charge Controller         Battery Bank                              DC Load




            Solar Panel


                                                                                    Inverter               AC Load




         Figure 5: Hybrid solar photovoltaic application




                                        Charge Controller        Battery Bank                             DC Load




             Solar Panel


                                                                                    Inverter              AC Load




              Electrical Grid




© 2013 Essential Energy India Private Limited
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3.1 Solution design considerations

         The solution design is based on the availability of sunshine in a particular geographic region. Table 5
         provides a theoretical approach to solution design and describes the parameters for solution design
         consideration.



         Table 5: Factors influencing solar photovoltaic solution design

          Parameters                                          Description
          Load                                                A detailed site load profile is required to design the total panel
                                                              capacity.

          Efficiency losses                                   Efficiency losses of the various tower site equipment influence solar
                                                              panel capacity. Solar photovoltaic technology as an energy source
                                                              needs the capacity to support the BTS load after considering the
                                                              losses of the battery, charge controller and other auxiliary loads.

          Energy incident                                     The availability of daily average energy incidents of 4-6 hours
                                                              duration largely impacts the energy output per panel. This
                                                              determines the panel capacity at the site.

          Efficiency of solar photovoltaic The efficiency of different panel sizes influences the total solution
          panels                                              footprint. Also the number of panels required to meet the energy
                     Panel capacity                          demand is determined by panel efficiency.
                     Panel size

          Battery configuration                               The charging current limitation of a given battery is fixed and based
                     Charging current limitation             on its specification. Battery capacity is designed according to the
                     Battery output voltage                  duration and availability of sunshine and charging current limitation,
                     required (Ah)                           especially when solar is the only source of battery charging.



         3.2 Opportunities and challenges of solar photovoltaic technology adoption in the
             Indian telecom industry

         Solar photovoltaic technology has come to be economically viable for different applications over the last few
         years as a result of technology maturity, the scale of adoption, mass manufacturing and innovation. Solar
         photovoltaic prices have reduced by 65% since 2001 and 73% since 200713. The trend in price fall is
         represented in figure 6 below.




         13
              http://thisisxy.com/blog/the-rise-of-green-mobile-telecom-towers


© 2013 Essential Energy India Private Limited
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14
         Figure 6: Price trend of solar photovoltaic modules, 2001 to 2012

                        4


                       3.5                                                   -73%


                        3

                                                                              -65%
                       2.5


                        2


                       1.5


                        1


                       0.5


                        0
                             2001                      2007                                 Q32012



         This significant price reduction has redefined the economic viability of solar photovoltaic solutions for telecom
         applications and could accelerate the speed of adoption. According to the Telecom Regulatory Authority of
         India (TRAI), switching to solar will save $1.4 billion in operating expenses for telecom tower companies
                                                          15
         compared to the current diesel solution .

         The table below shows solar photovoltaic deployment statistics by different telecom operators and
                                                               16
         infrastructure providers as of May 2013 . A few recent examples/initiatives of solar photovoltaic adoption
         include Bharti Airtel’s plan for deploying 3000 solar photovoltaic sites, Idea Cellular’s intention for 200 solar
         hybrid installations and Vodafone’s target of deploying 150 solar photovoltaic sites (in addition to the 390
                                                         17
         sites currently deployed by Vodafone) .

         Table 6: Adoption of solar photovoltaic applications for telecom towers18 (as per GSMA’s Green Deployment Tracker)

          Company                                                                              Solar towers
          Bharti Infratel Ltd                                                                  1350

          Vodafone Essar                                                                       390

          Idea Cellular                                                                        100

          Indus Towers                                                                         650

          GTL Infrastructure                                                                   80

          Total                                                                                2570



         Though government subsidies, lower interest rates on loans and the significant reduction in solar panel
         prices are encouraging, there are more challenges that need to be addressed including optimal solution
         design for various energy management scenarios, seamless integration with other renewable energy

         14
              GTM Research, X&Y Partners analysis
         15
              http://www.ccaoi.in/UI/links/fwresearch/conceltation%20paper%203.pdf
         16
              http://www.gsma.com/mobilefordevelopment/programmes/green-power-for-mobile/tracker
         17
              http://www.gsma.com/mobilefordevelopment/wp-content/uploads/2013/01/GPM-Bi-Annual-Report-January-2013.pdf
         18
              http://www.gsma.com/mobilefordevelopment/programmes/green-power-for-mobile/tracker


© 2013 Essential Energy India Private Limited
                                                                                                                              10
technology (RET) solutions and optimal configuration of solar photovoltaic panels as well as appropriate
         storage and space requirements.


         3.3 Government initiatives

         The Indian government is taking a multifaceted approach to accelerate energy security and to reduce the
         country’s dependency on fossil fuels. A few of the solar initiatives by various government bodies are outlined
         below:

         Jawaharlal Nehru National Solar Mission (JNNSM):

         This programme provides a comprehensive framework of solar power development in India. The Mission
         envisions 200 MW capacity of off-grid solar applications by the end of Phase-I (2013) and an overall
         installation of 2,200 MW by 2022. Under this scheme, systems of up to 100 kWp will receive funding support
         from the government.

         Ministry of New and Renewable Energy (MNRE):

         To encourage the usage of alternative and renewable energy sources, the MNRE provides the following
         support under the JNNSM scheme:

                
                                                                                                                                   19
                     The MNRE announced its support for 400 telecom towers using solar photovoltaic technology

                    Operator and infrastructure provides wide distribution of 400 MNRE-supported towers across India

                    The MNRE provides up to INR 81.00/Wp to offset the project cost

                    In April 2011, the MNRE revised the capital subsidy and benchmarked the cost of solar photovoltaic
                               20
                     systems to account for solar panel cost reduction in recent years

         Table 7: Statistics of 400 solar powered towers supported by the MNRE in India

         Operators                                   States                            Number of solar-powered towers

         Airtel                                       Bihar                                                100

         Indus                                  Andhra Pradesh                                             100

         GTL Infrastructure                      Uttar Pradesh                                             100

         BSNL                              Across 12 states of India                                       100
         Total                                                                                             400

         Universal Service Obligation Fund (USOF):

         To evaluate the viability of using renewable energy sources in the USO Fund projects, the USO Fund has
         collaborated with The Energy and Resources Institute (TERI) for the latter’s “Lighting a Billion Lives”



         19
          http://panchabuta.com/2011/08/22/400-telecom-towers-supported-in-pilot-project-for-use-of-solar-photovoltaic-power-systems-by-
         mnre-for-fy11-in-india/
         20
              http://www.solar-apps.com/Revised-Capital-Subsidy-and-Benchmark-cost-of-the-SPV-system.pdf


© 2013 Essential Energy India Private Limited
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initiative. The aim is to provide additional mobile charging facilities for rural areas. The project will cover
                                                               21
         5,000 villages across India over two years .


         3.4 Green energy mandate for telecom towers

         TRAI’s mandate requires that telecom companies should use renewable sources of energy to power at least
         50% of rural telecom towers and 20% of urban telecom towers by 2015. By 2020, the telecom companies
                                                                                                           22
         have to convert 75% of rural towers and 33% of urban towers to run on hybrid power . The MNRE’s recent
                                                                                                      23
         mandate to convert a minimum of 50,000 towers to solar photovoltaic technology                    immediately is another
         step towards ensuring compliance for the adoption of clean energy. Several proposals from the government
         have been rolled out for solar powered telecom sites such as Bharat Sanchar Nigam Limited’s (BSNL’s)

         tender for 15 telecom towers in Bihar24 and the Department of Telecommunications’ proposal for 2,200
                                                         25
         telecom towers for security networks .

         The Tower and Infrastructure Providers’ Association’s (TAIPA) initiative of forming Renewable Energy
         Service Companies (RESCOs) provides a simplified ecosystem of energy management for telecom towers,
         whereby infrastructure providers have to pay a fee based on the actual usage of power with no upfront
         investment in capital. Thus far, high levels of capital investment and inability of a single renewable energy
         technology to provide a full range of solutions across all geographies in India make it a challenge for
                                            26
         RESCOs to be successful .

         Due to these varied energy management scenarios, the Indian telecom industry is yet to benchmark the cost
         of operation for telecom towers.


         4        Case Studies
         The two case studies below provide an insight into the practicalities and economics of solar photovoltaic
         technology implementation by providing actual data at the live sites. The discussion includes details of the
         solution configuration and economic comparisons of the “before and after” solar hybrid solution installation at
         both sites.




         21
              http://www.tele.net.in/telefocus/item/11111-telecom-outreach-key-role-of-the-uso-fund
         22
              http://www.igovernment.in/site/telecom-towers-be-powered-renewable-energy
         23
              http://www.energynext.in/at-least-50000-mobile-towers-should-switch-to-solar-mnre/
         24
              Tender No.-25068/MS-O&M/CSPS/Non BSNL sites/12-13/06
         25
              http://www.ciol.com/ciol/news/187289/dot-seek-cabinet-approval-200-green-towers
         26
              Intelligent Energy Ltd, Green Solutions for Telecom Towers: Part I, March 2013


© 2013 Essential Energy India Private Limited
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4.1 Case study 1

         4.1.1     Site location
         Table 8: Site description of case study 1

          Site location
          Geographic location                                                District: Kolar
                                                                             State: Karnataka

          Distance from Bangalore                                            72 km

          Average daily temperature                                          35°C


         4.1.2     Site description
         Table 9: Site description of case study 1

          Site description                              Units                        Values
          Site type                                     -                            Outdoor

          Base transceiver station (BTS)                -                            Outdoor

          Number of BTS                                 -                            1

          BTS load                                      kW                           1

          Grid electricity panel                        kVA                          15

          Grid power availability                       hrs/day                      9

          Battery bank                                  Ah                           300

          Diesel generator                              kVA                          15

         Energy management before the solar photovoltaic hybrid installation

         Before the installation of the solar photovoltaic solution, the 15 hours of grid deficit was backed up by running
         a 15kVA diesel generator for 12 hours and the remaining 3 hours using a 300Ah battery. Figure 7 illustrates
         the power supply schematic at the site.




© 2013 Essential Energy India Private Limited
                                                                                                                       13
Figure 7: Power supply schematic of backup power with diesel generator prior to solar hybrid installation of
         case study 1




               15kVA EB                         PIU                                                           1kW
                                                                                 SMPS
                 Panel                                                                                        BTS




                                                                            300Ah Battery
                                                                                Bank


                               15kVA Diesel
                                Generator




         Energy management after the solar photovoltaic hybrid installation

         In February 2012, a solar photovoltaic solution was installed at the site. The solution includes 3kW solar
         panels, a central controlling unit (CCU) and a 600Ah VRLA battery bank that supports the (on average) 14
         hours of grid power outage per day. The static power conditioning unit (PCU) which replaces the earlier
         power interface unit (PIU) provides the additional hour of grid utilisation by managing grid voltage fluctuation.
         This turnkey solution is provided by ALTA Energy, India.

         The central controlling unit controls and monitors solar power utilisation, grid power utilisation and battery
         utilisation, as well as battery charging and discharging. The central controlling unit is programmed to
         prioritise the solar photovoltaic technology as a primary power source over all the other power sources.
         Hence, solar power is used when sunshine is available even if the grid power is available. The solution has
         an inbuilt data transfer unit (DTU) to store and transmit data for remote monitoring and sends SMS alerts
         through GPRS when service is required.

         Since installation, the diesel generator has not been in use. Figure 8 below illustrates the power supply
         schematic at the site.




© 2013 Essential Energy India Private Limited
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Figure 8: Power supply schematic, with solar photovoltaic installation for case study 1

                                                               ALL DC BOX




                                                                   CCU



                          3kW Solar Panel



                                                                   MPPT
               15kVA EB
                                            PCU
                 Panel




                                                                                      1kW
                                                                   SMPS
                                                                                      BTS




                                                               600Ah Battery
                                                                   Bank




         Table 10: Solution configuration of case study 1

          Components                                                                        Units                      Value
          Solar panel capacity                                                              kWp                             3

          PCU                                                                               kVA                             15

          Solar maximum power point                                                          kW                             5
          tracker controller (MPPT)

          SMPS                                                                               kW                             6

          Battery capacity                                                                   Ah                         600


         4.1.3       Site economics

         OPEX comparison

         Table 11 shows the monthly savings over the traditional diesel solution for backup power for the telecom
         tower after the solar photovoltaic solution was installed. Evaluated in the comparison are cost of the grid,
         cost of fuel for the diesel generator and operation and maintenance of the hybrid solution.

                                                                                                                       27
         Table 11: OPEX comparison of the “before and after” solar photovoltaic hybrid installation for case study 1

              Components                          Units              Before solar hybrid            After solar hybrid
          Cost of grid consumption                INR/day                      99                            69

          Diesel cost                             INR/day                      1186                           0

          Maintenance cost                        INR/day                      159                           37

          Total OPEX                              INR/day                      1444                         116

          Per unit OPEX                           INR/kWh                      60                             5

          Savings per kWh is calculated to INR 55.00

         27
              All numbers are presented as actuals from site


© 2013 Essential Energy India Private Limited
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Payback period calculations

         The solution costs INR 13,60,000. If the solution is financed for 120 months at 14% rate of interest, the
         monthly pay out for CAPEX is INR 21,116 which adds INR 5 per kWh.

         The graph in figure 9 compares the cost of energy of the solar photovoltaic solution with the diesel solution,
         considering an annual expenditure for diesel at various price points, installed capacity and operation and
         maintenance.

         Figure 9: Cash-flow projections in case study 1


          Payback period analysis for case study 1

                                                                                                 Diesel @70.00 INR/ltr
                                                                                                 Diesel @60.00 INR/ltr
                                                                                                 Diesel @52.25 INR/ltr




                                                                                                  Solar Photovoltaic




               Year 0 Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7 Year 8 Year 9


         The graph summarises the time frame of the realised return on investment for the installed solar photovoltaic
         solution in comparison with the yearly expenditure for the diesel solution. Considering the plausible price
         points of diesel at INR 52.25 per litre28, INR 60 per litre and INR 70 per litre, the respective payback periods,
         including CAPEX investment, are plotted. The chart demonstrates that, at INR 52.25 per litre of diesel, the
         return on investment on solar photovoltaic can be realised after approximately 2.5 years of deployment.
         When the price is at INR 60 or 70 per litre, the return on investment of solar photovoltaic technology will be
         much faster, that is between 1 and 2 years. In this case, for every INR 10 increase in diesel price the time
         frame of the return on investment for the solar photovoltaic solution is reduced by approximately 6 months.

         The savings resulting from the deployment of the solar photovoltaic system will result in an increase in free
         cash flow of INR 4,81,737 on an annual basis. In other words, the investment in the system will yield an IRR
         of 33% which is significantly higher than cost of capital (14%) and implies viability of the solution.

         This site has not received any capital subsidies for solar photovoltaic systems and hence such subsidies
         have not been used in the calculation.




         28
              Delhi diesel price in June 2013 INR 50.25 per litre, plus INR 2.00 logistic cost


© 2013 Essential Energy India Private Limited
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4.2 Case study 2

         4.2.1       Site location
         Table 12: Site location of case study 2

          Site location
          Geographic location                                                   District: Tumkur
                                                                                State: Karnataka
          Distance from Bangalore                                               150 km
          Average daily temperature                                             Minimum 18°C
                                                                                Maximum 35°C


         4.2.2       Site description
         Table 13: Site description of case study 2


          Site description                           Units                                         Value

          Site type                                  -                                             Outdoor

          BTS                                        -                                             Outdoor
          Number of BTS                              -                                             3
          BTS load                                   kW                                            3
          Grid power availability                    hrs/day                                       6

         Energy management before the solar photovoltaic hybrid installation

         Before the installation of the hybrid solution, the site’s backup power requirement of 18 hours a day on
         average was fulfilled by a 20kVA diesel generator running for a minimum of 10 hours per day and the
         remaining 8 hours by three batteries each of 400Ah capacity, with one for each of the service providers’
         BTSs. The diagram below represents the diesel generator power supply schematic at the site.

         Figure 10: Power supply schematic of backup power with diesel generator prior to solar hybrid installation in case study 2



                                                                                                                          BTS 1
                                                                                                           SMPS        Bharti Airtel
                                                                Low Tension
                                                               (LT) Panel for
          EB Panel          Energy Meter                                                               400Ah Battery
                                                                   Power
                                                                Distribution                               Bank
                                           20kVA Diesel
                                            Generator

                                                                                                                         BTS 2
                                                                                                           SMPS
                                                                                                                        Vodafone

                                                                                                       400Ah Battery
                                                                                                           Bank




                                                                                                                          BTS 3
                                                                                                           SMPS
                                                                                                                          BSNL

                                                                                                       400Ah Battery
                                                                                                           Bank




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Energy management after the solar photovoltaic hybrid installation

         In May 2009, a solar hybrid solution was installed to meet the 18 hours of outage. The solar hybrid solution
         includes a 10kW solar photovoltaic panel, a 5kW wind turbine, a 22kW SMPS and a 2500Ah battery. The
         400Ah battery bank also remains at each BTS. The battery was designed to ensure maximum energy
         storage and utilisation of solar hybrid power at the site. Figure 11 illustrates the power supply schematic at
         the site.

         Figure 11: Power supply schematic after the solar hybrid solution installation in case study 2


                                                                                                                  BTS 1




            EB Panel            Energy Meter                             LT Panel

                                                Diesel Generator

                                                                                                                  BTS 2



                                                   22kW SMPS




                                                                                                                  BTS 3

                       Solar Photovoltaic              Charge
                                                     Control Unit




                            Wind                 2500Ah Battery
                                                     Bank




         As depicted in the diagram, both solar and wind power generators are connected to their respective charge
         controller units (CCUs) for optimal power transfer. The following table provides configuration details of the
         solar hybrid solution.

         Table 14: Solar photovoltaic hybrid configuration in case study 2


          Components                                               Units                                  Value
          Solar panel capacity                                     kWp                                    10
          Solar charge controller and                              kW                                     10
          maximum     power      point
          tracker
          Wind turbine and charge                                  kWp                                    5
          controller
          Switch mode power supply                                 kW                                     22
          Battery capacity                                         Ah                                     2500




© 2013 Essential Energy India Private Limited
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On certain days, due to prolonged grid failure, lack of sunshine or total absence of wind, the diesel generator
         supports the backup power need. According to the site records, of the 18 hours of daily outage, on average
         almost 16 hours of backup power is provided by the solar hybrid solution and the remaining 2 hours by the
                               29
         diesel generator .

         In comparison with case study 1, since the load is higher here, the possibility of using the solar hybrid
         solution as a stand-alone option reduces.


         4.2.3       Site economics

         OPEX comparison

         Table 15 shows the monthly savings after the solar hybrid solution was installed. Evaluated in the
         comparison are the cost of grid consumption, cost of fuel for the diesel generator and the operation and
         maintenance of the hybrid solution.

         Table 15: Comparison of OPEX for the “before and after” solar photovoltaic hybrid installation for case study 230

              Components                           Units            Before solar hybrid                      After solar hybrid

          Cost of grid consumption                INR/day                   263                                        269

          Diesel cost                             INR/day                   1138                                       354

          Maintenance cost                        INR/day                   379                                        441

          Total OPEX                              INR/day                   1781                                      1064

          Per unit OPEX                         INR/kWh                      25                                        15

          Savings per kWh is calculated to INR 10

         Payback period calculation

         The solution which includes solar panels, wind turbine, battery bank, two charge controller units and SMPS
         of capacities described in table 13 costs a total of approximately INR 27,00,000. If the solution is financed for
                                                            31
         120 months at the rate of 14% interest , the monthly pay out for CAPEX is INR 42,200 which adds INR 25
         per kWh. It should be noted that the solar solution design has not been optimised at this site. With
         optimisation, there is an opportunity to reduce the CAPEX investment.

         The graph below compares the cost of providing backup power using the solar photovoltaic solution in
         comparison with a diesel-only solution at the various points of diesel price projection.




         29
              Based on site average actual data
         30
              All numbers are presented as actuals (March 2013) from site
         31
          60 months contract duration already completed and contract duration of 60 months likely to be extended as per discussions with
         BSNL


© 2013 Essential Energy India Private Limited
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Figure 12: Cash-flow projection in case study 2


              Pay back period analysis for case study 2
                                                                                                 Diesel @ 70.00INR/ltr
                                                                                                 Diesel @ 60.00INR/ltr

                                                                                                 Diesel @ 52.25.00INR/ltr




                                                                                                 Solar photovoltaic with around 80%
                                                                                                 subsidies




               Year 0 Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7 Year 8 Year 9



         The graph summarises the time frame of the realised return on investment for the installed solar photovoltaic
         solution against the yearly expenditure of the diesel solution. At the time of this evaluation, the price of diesel
                                      32
         is INR 52.25 per litre . Given that the deregulation of diesel prices is expected at any time, diesel at INR 60
         per litre and INR 70.00 per litre is used in this analysis chart. From the chart it can be determined that with an
         increase of every INR 10 per litre in the price of diesel, the solar photovoltaic payback period reduces by
         approximately 2.5 years. However, for this 3kW site, at the current price of INR 52.25 per litre and without
         any subsidy from the government, the time frame of solar photovoltaic payback period is approximately 9
         years.

         The savings resulting from the deployment of the solar photovoltaic system will result in an increase in free
         cash flow of INR 2,61,456 on an annual basis. In other words, the investment in the system will yield an IRR
         of -1% which is significantly lowers than cost of capital (14%) and implies non-viability of the solution over the
         contract duration of 10 years.

         As a proof-of-concept site, this deployment received around 80% subsidy from the government, making the
         solution economically viable from the date of installation as shown in figure 12.


         4.3 Challenges on the ground

         Due to the diversity of energy management scenarios, viability of the technology and maturity of the solution,
         adoption of renewable energy technology has multiple challenges before it can be adopted at large scale
         across the country. Table 16 captures a few of the major challenges encountered by both test case sites.




         32
              Delhi diesel price in June 2013 INR 50.25 per litre, plus INR 2.00 logistic cost


© 2013 Essential Energy India Private Limited
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Table 16: List of challenges faced by telecom infrastructure providers and RESCOs in deploying RET solutions at large
         scale

          Parameters                                                      Challenges

          Technology                     Seamless integration with other energy sources such as wind turbines, biomass
          challenges                      and fuel cells

                                         Configuration of off-grid applications

                                         Complex system integration (configuration is not optimised for consumption)
          Design and                     Prioritisation of solar photovoltaic technology among other available energy
          configuration                   sources for frequent outages
          challenges                     Optimisation of solution configuration in terms capacity installed

          Deployment                     Higher foot print requirement
          challenges
                                         Optimum exposure to sunshine for the solar panel

                                         Poor operation and maintenance services
          Scalability                    Capital intensive
          challenges
                                         Geographical limitation

                                         Variety of energy management scenarios and flexibility of solution integration
          Economic                       High CAPEX
          challenges
                                         Replacement of batteries further increases the capital investment

                                         Not enough encouragement by government to overcome the tipping point in the
                                          adoption of the technology at large scale



         5      Future of Solar Photovoltaic Technology for Telecom
         In telecom, solar photovoltaic technology has experienced a better rate of adoption to date in comparison
         with other RETs. Achieving optimal configuration is still a barrier for large-scale adoption of the solution. As
         shown in the case studies, telecom sites with lower load profiles benefit from solar photovoltaic technology
         installations from day one whereas for telecom sites with higher load profiles, it is difficult to justify the cost of
         capital investment required. The growing cost of diesel and relevant subsidies may tip the balance in favour
         of solar investment in some of these cases. For higher load profile sites, battery capacity is high thereby
         increasing capital investment and maintenance requirements. At times, these sites have to fall back on diesel
         generators to supplement the gap left by the solar solution.

         With innovative business models like the OPEX model solution where the initial capital investment is
         financed and the telecom tower owner pays only for the usage, the solar adoption rate can increase
         significantly.

         While solar offers a good solution for many telecom towers with lower load profiles, the deployment
         constraints at other towers make it necessary to evaluate the capabilities of alternative renewable energy
         technologies aside from solar, such as biomass power and fuel cells. The next edition of this whitepaper will
         discuss the practical and economic viabilities of these alternative technologies.

© 2013 Essential Energy India Private Limited
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Intelligent Energy acknowledges the contribution of ALTA Energy India and all others, for sharing information and conducting primary
         research used in the development of this white paper.

         A special thanks to Mr P.K. Panigrahi, Sr. Dy. Director General (BW), DOT and Mr V.K. Hirna, Dy. Director General (Electrical), DOT for
         their support.

         About Intelligent Energy

         Intelligent Energy delivers efficient and clean energy technology for the global consumer electronics, automotive and stationary power
         markets – from compact energy packs for mobile devices, to power-trains for zero-emission vehicles, and stationary power units for the
         always-on infrastructure.

         Our unique technology architecture is used by global blue chip companies to create differentiated, cost-efficient fuel cell power systems
         for mass market applications. It enables Intelligent Energy and our industry partners to solve the challenges of continuous power and
         productivity, by creating convenient everyday energy solutions to power your life.

         Intelligent Energy operates globally, with offices in the Americas, Europe and Asia.

         www.intelligent-energy.com

         About Essential Energy

         Essential Energy is a wholly owned subsidiary of Intelligent Energy Holdings, plc.

         Essential Energy was formed to address the growing gap between supply and demand in countries like India. The large number of new
         innovative technologies and novel methods for delivery of energy from these technologies has created confusion among customers.
         Essential Energy was created to partner with such customers allowing them to meet their energy requirements in a responsible and
         economical manner.

         We work with our customers to deliver efficient solutions and educate them to adopt energy modest loads while not compromising on
         their requirements.

         We are based out of Bangalore, India and have a team of experienced professionals with illustrious backgrounds in energy, finance and
         power systems engineering

         www.e2-india.com




© 2013 Essential Energy India Private Limited
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