Photovoltaic Solar Cell Technologies Analysing the State of the Art

Solar electricity is more expensive than that produced by traditional sources. But over the past two decades, the cost gap has been closing. Solar photovoltaic (SPV) technology has emerged as a useful ability source of applications such as lightning, meeting the electricity needs of villages, hospitals, telecommunication, and houses. The long and increasing authorisation of crystalline silicon in photovoltaic (PV) market is perchance surprising given the wide multifariousness of materials capable of producing the photovoltaic effect. PV based on silicon wafers has captured more xc% market share considering it is more reliable and generally more efficient than competing technologies. The crystalline silicon PV is reliable as far as long term stability in real field but it is not economically viable due to starting textile silicon itself costly. Merely yet, inquiry continues on developing a diverse set up of culling photovoltaic technology. Now PV technology is being increasingly recognized as a part of the solution to the growing free energy claiming and an essential component of future global energy production. In this paper, we requite a cursory review nearly PV technology specially crystalline silicon PV including the world and Indian PV scenarios.

one. Introduction

Solar energy is the almost readily available and gratis source of energy since prehistoric times although it is used in most primitive way. Solar energy can exist used directly for heating and lighting domicile and buildings, for generating electricity, cooking nutrient, hot-water heating, solar cooling, drying materials, and a variety of commercial and industrial uses [1–iii].

Solar free energy can be utilized through two unlike routes, solar thermal routes and solar photovoltaic routes [4, 5]. Solar energy can exist converted into thermal energy with the aid of solar collectors and receivers known every bit solar-thermal devices. PV-created direct current (DC) electricity that can be used as such is converted to alternating current (AC) or stored for later use. This blazon of solar electricity is more expensive than that produced past traditional sources. But over the past two decades, the cost gap has been closing. Solar photovoltaic (SPV) technology has emerged every bit a useful power source of applications such as lightning, meeting the electricity needs of villages, hospitals, telecommunication, and houses.

The long and increasing authorization of crystalline silicon in photovoltaic (PV) market is possibly surprising given the wide variety of materials capable of producing the photovoltaic effect. PV based on silicon wafers has captured more than ninety% market share because it is more reliable and more often than not more than efficient than competing technologies [vi]. Merely it is not economically viable due to starting fabric silicon itself costly. Therefore, enquiry continues on developing a various set of alternative photovoltaic technology.

At present PV engineering science is existence increasingly recognized equally a function of the solution to the growing energy challenge and an essential component of hereafter global energy production. In this paper, we give a brief review near particularly crystalline silicon PV engineering including the world and Indian PV scenarios.

2. Photovoltaic Technologies

The early on authorisation of silicon in the laboratory has extended to the market for commercial modules. Crystalline silicon designs have never accounted for less than eighty% of the market for commercial modules and nearly 15–eighteen% of the market was not crystalline silicon. It was based on amorphous silicon-a PV engineering science that is nearly exclusively used for consumer electronics such every bit watches and calculators. If we were to exclude electronics and ascertain the market equally electricity delivery system of ane kW or more than, current production is dominated past single-crystal and polycrystalline silicon modules, which represent 94% of the market. There are a wide range of PV cell technologies on the market today, using different types of materials, and an even larger number will be available in the future. PV cell technologies are ordinarily classified into three generations, depending on the basic material used and the level of commercial maturity [vii]. (i) Kickoff-generation PV systems (fully commercial) use the wafer-based crystalline silicon (c-Si) technology, either single crystalline (sc-Si) or multicrystalline (mc-Si). (ii) Second-generation PV systems (early on market deployment) are based on thin-film PV technologies and generally include three chief families: (1) baggy (a-Si) and micromorph silicon (a-Si/c-Si); (2) cadmium telluride (CdTe); and (3) copper indium selenide (CIS) and copper indium-gallium diselenide (CIGS). (iii) Third-generation PV systems include technologies, such equally concentrating PV (CPV) and organic PV cells that are withal under sit-in or have not yet been widely commercialized, likewise as novel concepts under evolution.

Commercial product of c-Si modules began in 1963 when Sharp Corporation of Nihon started producing commercial PV modules and installed a 242 Watt (Westward) PV module on a lighthouse, the globe's largest commercial PV installation at the time (Thousand.A. Green 2001). Total PV cells/modules production past region 2007–2011 (data: Navigant consulting graph: PSE AG 2012) is shown in Figure i. It has been observed that Japan attributed to increase their PV cells/modules product capacity from 1997 to 2004 so drastically reduced their production capacity after 2004. Same tendency was observed in PV cells/module product in Europe also simply upwards to year 2008, and and then they reduced their product capacity. On the other hand in yr 1997, PV cells/module product chapters of United states was the highest, and later on and so they reduced their product capacity every yr. Whereas PV cells/modules production scenarios of China were just the reverse compared to U.s.. Given the vast potential of photovoltaic engineering science, worldwide production of terrestrial solar cell modules has been rapid over last several years, with China recently taking the pb in total production volume as shown in Figure ane. Another interesting pic related to the global cumulative PV installation until 2011 was noticed as shown Figure 2. It was observed that notwithstanding Germany including other European country contributed to major role towards the global cumulative PV installation until 2011, that is, 70% of global PV installation. And then PV installation marketplace in Europe is too much promising till now compared to other countries.

Effigy three shows the PV product evolution by technology in the year 2011. It was from this global PV production scenario in the year 2011 that almost more than than 85% of the solar cell production was based on crystalline silicon. Even it was observed that fifty-fifty PV installation scenario, crystalline silicon solar prison cell, dominated the world marketplace as indicated in Figure 4.

The year wise efficiency record of solar cell made nether different technological approaches is shown in Figure 5. From this record, it is evident that laboratory monocrystalline silicon solar cell efficiency was even so college compared to other existing solar cell technology except III-V multijunction concentrator solar jail cell and monocrystalline concentrator solar prison cell, respectively.

Best laboratory prison cell versus best laboratory module fabricated under different PV technology is also given in Figure 6. It is observed from Figure 6 that the lab. made monocrystalline solar cell and module efficiency were 25% and 22.ix%, respectively, whereas multicrystalline solar jail cell and module efficiency were xx.iv% and 18.2%, respectively. 1 important point to be noted is that the efficiency of thin film CI(G)Due south solar cell was nineteen.six% (area 0.42 cm²). And so there is enough scope of work related to CI(Chiliad)South solar cell technology.

Later on more than xx years of R&D, thin-motion picture solar cells are beginning to exist deployed in pregnant quantities. Thin-flick solar cells could potentially provide lower toll electricity than c-Si wafer-based solar cells. However, this is non certain, as lower capital letter costs including lower production and materials costs are first to some extent past lower efficiencies and very low c-Si module costs brand the economics fifty-fifty more challenging.

Thin-film solar cells comprised successive thin layers, just 1chiliad to 4m thick, of solar cells deposited onto a large, cheap substrate such as drinking glass, polymer, or metal. As a consequence, they require a lot less semiconductor textile to be manufactured in club to absorb the aforementioned amount of sunlight (upward to 99% less material than crystalline solar cells). In add-on, thin films can be packaged into flexible and lightweight structures, which tin can exist hands integrated into edifice components (edifice-integrated PV, BIPV).

Third-generation PV technologies are at the pre-commercial phase and vary from technologies under demonstration (e.g., multijunction concentrating PV to novel concepts still in need of basic R&D (e.g., quantum-structured PV cells). Some third-generation PV technologies are commencement to exist commercialized, merely how successful they will exist in taking market share from existing technologies remains to be seen.

Novel and emerging solar cell concepts in addition to the previously mentioned third-generation technologies; at that place are a number of novel solar cell technologies under development that rely on using quantum dots/wires, quantum wells, or super lattice technologies (Nozik, 2011 and Raffaelle, 2011). These technologies are probable to be used in concentrating PV technologies where they could achieve very high efficiencies by overcoming the thermodynamic limitations of conventional (crystalline) cells. However, these high-efficiency approaches are in the fundamental materials inquiry phase. Furthermore from the market are the novel concepts, often incorporating enabling technologies such as nanotechnology, which aim to alter the active layer to better friction match the solar spectrum (Leung, 2011).

A newer technology, sparse-film PV, accounts for x%–15% of global installed PV capacity [eight]. Rather than using polysilicon, these cells employ thin layers of semiconductor materials like amorphous silicon (a-Si), copper indium diselenide (CIS), copper indium gallium diselenide (CIGS), or cadmium telluride (CdTe). The manufacturing methods are like to those used in producing flat console displays for computer monitors, mobile phones, and televisions; a thin photoactive picture is deposited on a substrate, which can exist either glass or a transparent film. After, the film is structured into cells. Unlike crystalline modules, thin-picture modules are manufactured in a single step. Thin-picture show systems usually cost less to be produced than crystalline silicon systems but have substantially lower efficiency rates [9]. On boilerplate, sparse-film cells convert 5%–13% of incoming sunlight into electricity, compared to eleven%–20% for crystalline silicon cells. Still, as thin film is relatively new, it may offering greater opportunities for technological improvement.

3. Monocrystalline Silicon Solar Cell Technology

Traditional c-Si cell design and its evolution up to year 2000 have been focused on in the Figure 7. Different types of c-Si cell structure have been used for improving the efficiency of crystalline silicon solar cell. Metallic-insulator NP solar cell (MINP), passivated emitter solar cell (PESC), passivated emitter and rear cell (PERC), passivated emitter, rear locally diffused cell (PERL), and interdigitized back contact cell (IBC) are useful solar cell structures used past the different well-recognized universities or laboratories.

(a)

(b)

In MINP construction, there was SiO₂ passivation surface underneath contact and current conduction by tunneling through the sparse oxide [x].

But in PESC structure [11, 12], there was no oxide underneath contact as shown in Effigy 8. Contact width is reduced past laser microgrooving as shown in Effigy 9.

In PERC structure as shown in Figure 10(a), rear surface of the solar cell was passivated and contact was made by point rear contact, whereas in PERL structure [13], rear contact is fabricated past local BSF (dorsum surface field) at rear point contact by improvidence every bit shown in Effigy 10(b).

Interdigitized back contact solar prison cell [xiv] is now well-known promising solar cell structure used by SUNPOWER in their solar cell production line. R.M. Swanson is a key person for the evolution of IBC solar jail cell structure [15]. In this structure, all solar prison cell contacts were made from rear surface. Both front and back surface fields accept been implemented in this construction as shown in Figure xi.

Researchers in the area of crystalline silicon continuously tried to detect out a new unproblematic route past which big area loftier efficiency tin exist achieved. In 2011, Lai [sixteen] already achieved nineteen.four% efficient planar cells on CZ silicon using simple jail cell technologies. Effigy 12 is the structure used during fabrication by Lai.

1 key to the evolution of any photovoltaic technology is the cost reduction associated with achieving economies of scale. This has been evident with the evolution of crystalline silicon PVs and will presumably exist truthful for other technologies as their product volumes increase. Price trend of crystalline installed PV in the world market is shown in Figure 13.

(a)

(b)

4. Indian PV Scenarios

Developing countries, in particular, face situations of limited energy resources, especially the provision of electricity in rural areas, and in that location is an urgent need to address this constraint to social and economic development. India faces a meaning gap between electricity demand and supply. Demand is increasing at a very rapid rate compared to the supply. According to the Earth Bank, roughly 40 percent of residences in India are without electricity. In addition, blackouts are a common occurrence throughout the country's main cities. The World Banking company also reports that one-3rd of Indian businesses believes that unreliable electricity is one of their primary impediments to practise business. In addition, coal shortages are further straining power generation capabilities.

Republic of india is endowed with rich solar energy resource. The average intensity of solar radiations received on India is 200 MW/km foursquare (megawatt per kilometer square). With a geographical area of 3.287 one thousand thousand km square, this amounts to 657.4 meg MW. Still, 87.five% of the state is used for agriculture, forests, fallow lands, and then along, 6.7% for housing, manufacture, so along, and five.viii% is either barren, snow bound, or by and large inhabitable. Thus, merely 12.5% of the country area amounting to 0.413 million km square can, in theory, be used for solar energy installations. Even if 10% of this area tin exist used, the available solar free energy would exist 8 one thousand thousand MW, which is equivalent to five 909 mtoe (million tons of oil equivalent) per yr.

In order to meet the situation, a number of options are considered. Power generation using freely available solar energy is one such choice. Fortunately, India is both densely populated and has high solar insolation, providing an ideal combination for solar power in India. Jawaharlal Nehru National Solar Mission is one of the major global initiatives in promotion of solar energy technologies, appear by the Government of India under National Action Programme on Climate Alter. Mission aims to accomplish grid tariff parity past 2022 through the big-scale utilization and rapid diffusion and deployment of solar technologies beyond the country at a calibration which leads to cost reduction and promotes the research and development activity to local manufacturing and infrastructural support. Table 1 shows the route map of Jawaharlal Nehru National Solar Mission.

Application segment	Target for phase I (2010–13)	Cumulative target for phase 2 (2013–17)	Cumulative target for stage 3 (2017–22)
Grid solar power including roof elevation and distribution grid continued plants	one,000 MW	four,000 MW	twenty,000 MW
Off-grid solar applications	200 MW	1,000 MW	2,000 MW
Solar collector	7 one thousand thousand sq.meters	15 meg sq.meters	xx 1000000 sq.meters

Nether the programme, solar-powered equipment and applications would be mandatory in all government buildings including hospitals and hotels. The scope for solar PV growth in India is massive, peculiarly growth in distributed solar as over 600 million people—mostly in rural areas—currently practise not have access to electricity. It is useful for providing filigree quality, reliable power in rural areas where the line voltage is low and bereft to be catered to connected load. The Government of India is planning to electrify eighteen,000 villages by year 2012 through renewable free energy systems especially by solar PV systems. This offers tremendous growth potential for Indian solar PV industry.

The growth of Indian PV is shown in the Figure 14 indicating that the increment of module product upwards to year 2011 was pregnant compared to solar cell production by the Indian manufacturer. This may be due to availability to solar cell with much lower prices from Chinese solar prison cell manufacturer and initial investment of the module plant with lower CAPEX compared to setting up new solar cell establish in India. But the status of Indian PV is related to the awarding in different areas past installing 53,00,000 systems (~2600 MW) upwardly to 2012 as shown in Effigy 15.

Some other important achievement in the Indian PV surface area is 1044 MW chapters new Filigree Solar Power projects commissioned by September, 2012 in sixteen States as indicate state wise in Figure 16. From this pictorial presentation, it is clear that Gujarat state much alee compared to the remainder of other state every bit far equally installation of Grid Solar PV Power Plant in Republic of india.

five. Conclusion

One key to the development of any photovoltaic technology is the cost reduction associated with achieving economies of scale. This has been evident with the evolution of crystalline silicon PVs and will presumably exist true for other technologies every bit their production volumes increase. Given the vast potential of photovoltaic applied science, worldwide production of terrestrial solar cell modules has been rapid over the last several years, with Cathay recently taking the atomic number 82 in total product book.

Fortunately Bharat is both densely populated and has loftier solar insolation, providing an ideal combination for solar power in India. The Authorities of Bharat is planning to electrify xviii,000 villages by year 2012 through renewable energy systems particularly solar PV systems. This offers tremendous growth potential for Indian solar PV industry.

Acknowledgments

Authors would similar to thank Meghnad Saha Institute of Technology, TIG, for providing the infrastructural support to acquit out inquiry activity in this area. The authors also gratefully acknowledge the DST, Government of Republic of india for fiscal back up for carrying out solar-cell-related research activity.

Copyright

Copyright © 2013 Utpal Gangopadhyay et al. This is an open up admission article distributed under the Artistic Commons Attribution License, which permits unrestricted apply, distribution, and reproduction in any medium, provided the original work is properly cited.

brownwoorst.blogspot.com

Source: https://www.hindawi.com/journals/cpis/2013/764132/

Share this post