PHOTOVOLTAIC CELLS

Transcription

1 PHOTOVOLTAIC CELLS

2 How Photovoltaic Cell Work When sunshine that contain photon strike the panel, semiconductor material will ionized Causing electron to break free from their bond. Due to the structure of semiconductor, electron are forced to flow in one direction which creating electrical current Photovoltaic cells are not 100% efficient in part due to reflection of light spectrum, some too weak to create electricity (IR ray) and some create heat energy instead of electricity (UV ray)

3 Monocrystalline Silicon PV Panel Made from a single silicon crystal, more efficient, though more expensive than the newer and cheaper polycrystalline and thin-film PV panel technologies Easily recognizable by an external even colouring and uniform look, indicating high-purity silicon Monocrystalline solar cells are made out of silicon ingots, which are cylindrical in shape Have the highest efficiency rates since they are made out of the highest-grade silicon. The efficiency rates of monocrystalline solar panels are typically 15-20%.

4 Polycrystalline Silicon PV Panel Recognizable by a visible grain, a metal flake effect Can be synthesized by allowing Silicon (liquid) to cool using a seed crystal. The other methods for crystallizing amorphous silicon to form is by using high temperature Chemical Vapour Deposition (CVD) This Polycrystalline Silicon panel is almost as good as single cell Monocrystalline Silicon panels. But have better efficiency than thin film solar panels.

5 Thin-Film PV Panel Thin Film is a second generation solar cell that is made by depositing one or more thin layers of material on substrate such as plastic, metal or glass There are several type of thin-film photovoltaic panel used such as Organic Photovoltaic Cell (OPV), Amorphous Silicon (a Si / TF Si), Copper Indium Gallium Selenide (CIGS / CIS), Perovskite, Dye Sensitized (DSSC) and Cadmium Telluride (CdTe) DSSC Dye Sensitized Thin Film Perovskite OPC Organic Photovoltaic Cell a Si / TF Si Amorphous Silicon CIGS / CIS Copper Indium Gallium Selenide CdTe Cadmium Telluride

6 Organic Photovoltaic Cell (OPC) OPC consists of one or several photoactive materials sandwiched between two electrodes. In bilayer OPC cell, sunlight is absorbed by Photoactive Layer. This layer contain donor and acceptor semiconducting organic material that able to generate photocurrents. Have ability to be utilized in large area and flexible solar modules The manufacturing cost of this cell can be reduced due to their lower cost compared to silicon-based materials and the ease of device manufacturing + + To Anode - - Charge Separation Sunlight Absorbed To Cathode

7 Amorphous Silicone (a Si / TF Si) Formed by depositing a thin layer of silicon material (using vapour) about 1 µm thick on a substrate material such as glass or metal The overall thickness of solar cell is just 1 µm, or about 1/300th the size of mono - crystalline silicon solar cell Red Cell Green Cell Back Reflector Film Layer Blue Cell Transparent Conductive Oxide Film Thickness of Multijunction Cell = <1.0 µm The efficiency rate of this cell are lesser than crystalline silicone panel due to Staebler Wronski effect - defect density of hydrogenated amorphous silicon (a- Si:H) increases with light exposure, causing an increase in the recombination current and reducing the efficiency Flexible Stainless Steel Substrate Based on the research, Staebler Wronski effect can be reduced by using Silane Gas

8 Copper Indium Gallium Selenide (CIGS) Sunshine Transparent Conductive Oxide (TCO) Cadmium Sulfide (CdS) Copper Indium Gallium Selenide (CIGS) Molybdenum Substrate (Glass, Metal Foil) Manufactured by depositing a thin layer of copper, indium, gallium and selenide on glass or plastic backing, along with electrodes on the front and back to collect current The layers are thin enough to be flexible, allowing them to be deposited on flexible substrates. However, as all of these technologies normally use hightemperature deposition techniques, the best performance normally comes from cells deposited on glass. Commercial CIGS modules typically have efficiencies between 12% and 14%

9 Cadmium Telluride (CdTe) Based on the use of cadmium telluride, a thin semiconductor layer designed to absorb and convert sunlight into electricity Smallest carbon footprint, lowest water use and shortest energy payback time of all solar technologies Glass Substrate Indium Tin Oxide (Low Sensitivity TCO) Tin Oxide (High Sensitivity TCO) n-doped Cadmium Sulphide (Window Layer) p-doped Cadmium Telluride (Absorber) Metal Contact (Ti or Au) Currently industry uses thermal PVD methods for the deposition of the materials utilised in the cell (either Close Space Sublimation (CSS) or Vapour Transport Deposition (VTD) Sputtering is an alternative PVD deposition method which allows much better uniformity control. Moreover, sputtering allows reduction of the growth temperatures from ºC used for CSS and VTD to, potentially, as low as room temperature.

10 Perovskite Type of mineral that was first found in the Ural Mountains and named after Lev Perovski who was the founder of the Russian Geographical Society. A perovskite structure is any compound that has the same structure as the perovskite mineral Formed of calcium, titanium and oxygen in the form CaTiO 3. Meanwhile, a perovskite structure is anything that has the generic form ABX 3 and the same crystallographic structure as perovskite (the mineral) Dependant on which atoms/molecules are used in the structure, perovskites can have an interesting properties including superconductivity, giant magnetoresistance, spin dependent transport (spintronic) and catalytic properties Perovskite (CaTiO 3 ) A schematic of a perovskite crystal structure

11 Perovskite The most efficient devices so far have been produced with the following combination of materials in the usual perovskite form ABX 3 A = An organic cation - methylammonium (CH 3 NH 3 )+ B = A big inorganic cation - usually lead(ii) (Pb 2 +) X 3 = A slightly smaller halogen anion usually chloride (Cl-) or iodide (I-) A B X 3 Organo Metal Trihalide (or trihalide) Methylammonium Lead Iodide (or triiodide) Plumbate Chloride (or trichloride) Glass ITO Hole Interface Layer Perovskite ABX 3 Electron Interface Layer Metal Back Contact

12 Dye Sensitized (DSSC) Likened to artificial photosynthesis due to the way in which it mimics natures absorption of light energy A disruptive technology that can be used to produce electricity in a wide range of light conditions, indoors and outdoors, enabling the user to convert both artificial and natural light into energy Electrically Conductive Electrode e Dye Light/Indoor Light Counter Electrode Thin and mechanically robust allowing for heat to be radiated quickly and efficiently, which avoids the problem faced by traditional silicon-based solar cells DSSCs work in low-light conditions. Due to their very favourable electrochemical kinetics, DSSCs do not share the same cut-off point as other solar cells in terms of charge carrier mobility and recombination e TiO 2 e e e e e e e DC Current 3I- I - 3 Electrolyte e e

13 Dye Sensitized (DSSC) As sunlight strikes the molecular dye, after passing through the transparent electrode, an electron is ejected and makes its way through the titanium dioxide (TiO 2 ) nanoparticle layer The electrons flow towards the transparent electrode where load collecting takes place before flowing on to an external circuit The electrons are reintroduced into the cell through the counter electrode where the electrolyte transports the electrons to the dye molecule

14 Comparison (Crystalline Silicon vs Thin Film) Cell Technology Crystalline Silicon Thin Film Types of Technology Voltage Rating (Vmp/Voc) *higher is better as there is less gap in Voc and Vmp Temperature Coefficient I-V Curve Fill Factor *idealized PV cell is 100% Monocrystalline Silicon Polycrystalline Silicon String Ribbon Amorphous Silicon Copper Indium Gallium Selenide (CIGS) Organic Photovoltaic (OPV) Cadmium Telluride (CdTe) Dye Sensitized (DSSC) 80% - 85% 72% - 78% Higher Lower *lower is beneficial at high ambient temperature 73% - 82% 60% - 68%

15 Comparison (Crystalline Silicon vs Thin Film) Cell Technology Crystalline Silicon Thin Film Module Construction Inverter Compatibility and Sizing Mounting Systems DC Wiring With Anodized Aluminium Lower temperature coefficient is beneficial Industrial Standard Industrial Standard Frameless, sandwiched between glass; lower cost and weight Need to consider factor such as temperature coefficient, different of Voc and Vmp Special Clips and Structure but in some cases, significant save in labour cost May need combination of circuits and fuses Application Type Residential, Commercial and Utility Commercial and Utility Required Area Industrial Standard May require up to 50% more space for given project size

16 Efficiency and Cost Comparison (Crystalline Silicon vs Thin Film) 1 st Generation PV Technology Units Monocrystalline Silicon Polycrystalline Silicon Best Research Solar Cell Efficiency at AM1.5* Confirmed Solar Cell Efficiency at AM1.5 Commercial PV Module Efficiency at AM1.5 Confirmed Maximum PV Module Efficiency % 24.7 % % % PV Module Cost** USD/W State of Commercialisation Mature with large scale production Mature with large scale production *Standard Testing Condition, Temperature 25 C, Light Intensity 1000W/m^2, Air Mass 1.5.

17 Efficiency and Cost Comparison (Crystalline Silicon vs Thin Film) 2 nd Generation PV Technology Units Amorphous Silicon CIGS CdTe Best Research Solar Cell Efficiency at AM1.5* Confirmed Solar Cell Efficiency at AM1.5 Commercial PV Module Efficiency at AM1.5 Confirmed Maximum PV Module Efficiency % 10.4 Single Junction 13.2 Tandem % % % 7.1 / PV Module Cost** USD/W State of Commercialisation Early deployment phase, medium scale production Early deployment phase, medium scale production Early deployment phase, small scale production *Standard Testing Condition, Temperature 25 C, Light Intensity 1000W/m^2, Air Mass 1.5.

18 Efficiency and Cost Comparison (Crystalline Silicon vs Thin Film) 3 rd Generation PV Technology Units Concentrated PV Dye-Sensitized (DSSC) Organic PV (OPV) Best Research Solar Cell Efficiency at AM1.5* Confirmed Solar Cell Efficiency at AM1.5 Commercial PV Module Efficiency at AM1.5 Confirmed Maximum PV Module Efficiency % % % % PV Module Cost USD/W State of Commercialisation Just commercialized, small scale production R&D Phase R&D Phase *Standard Testing Condition, Temperature 25 C, Light Intensity 1000W/m^2, Air Mass 1.5.

19 Solar Cell Efficiency (Research Cell)

20 Solar Cell Degradation The rated power output of solar panels typically degrades at about 0.5%/year However, thin-film solar panels (a-si, CdTe and CIGS) degrades faster than panels that are based on mono and polycrystalline solar panels Due to extreme weather, panels in hot climates exhibited large decreases in production over time - close to 1% per year - mainly due to high levels of UV exposure Solar panels typically degrade faster in the first couple of years of their life Solar Cell Type Output Loss in One Year (%) Pre Post Cadmium Telluride (CdTe) Amorphous Silicon (a-si) Copper Indium Gallium Selenide (CIGS) Monocrystalline Silicon Polycrystalline Silicon

21 Future of Solar Energy (ASEAN PV Market Share) ASEAN PV MARKET SHARE Indonesia Malaysia Thailand Philippines Vietnam Others [CATEGORY NAME] [VALUE] [CATEGORY [CATEGORY NAME] NAME] [VALUE] [VALUE] [CATEGORY NAME] [VALUE] With annual solar radiation levels ranging from 1,460 to 1,900 kwh/m^2 per year the region has some of the highest yields in the world [CATEGORY NAME] [VALUE] [CATEGORY NAME] [VALUE] While Thailand and the Philippines dominate the market today, in just a few short years, the other ASEAN countries will be competing for the title of the top PV market in ASEAN s rapidly growing solar power region

22 Future of Solar Energy (ASEAN Total Energy Consumption) Total overall energy consumption increase >100 % in 2013 from Highest overall energy consumption in Thailand and Indonesia (2013).

23 Future of Solar Energy (ASEAN Share of Renewables in Primary Consumption) Total energy consumption for renewable energy decrease from 43 % in 1990 to 23 % in 2012 Renewable energy consumption for Malaysia and Indonesia are less than 25 %

24 Future of Solar Energy (ASEAN Share of Renewables in Electricity Production) No so much change in total share of electricity production (including hydro) from 1990 to 2012 Malaysia and Indonesia share of renewable electricity production (including hydro) are around 8 to 30 % from total energy demand

25 LJ UHV TECHNOLOGY KGC SAINTIFIK Thank You This slide presentation is prepared by Research & Development Team, KGC Saintifik Any inquiries, feel free to us at