Professor Humayun A Mughal Chairman, Akhter Group PLC Photovoltaic Technology. The answer to Global Warming?

Global Warming – a Reality Energy Production – major Contributor Growing Demand for Electricity – no Going back Green Energy – is The Only Option The PHOTOVOLTAIC technology – is the Green Option PV is the ANSWER to our needs - Economic, Environmentally friendly and Renewable Key Issues

Warming World At-a-glance: Climate change - evidence and predictions

Long Term High At-a-glance: Climate change - evidence and predictions

Sea Level Rise

Thinning Ice At-a-glance: Climate change - evidence and predictions

Growing Emissions At-a-glance: Climate change - evidence and predictions

A Warmer Future At-a-glance: Climate change - evidence and predictions

Cows are guilty of speeding up Global Warming. Quick Climate Quiz B - False A - True Methane is the second most significant greenhouse gas and cows are one of the greatest methane emitters. Their grassy diet and multiple stomachs cause them to produce methane, which they exhale with every breath. A - True

D – Three times as fast C – Twice as fast B – The same A – Half as fast Roughly how fast is the Arctic warming compared to the rest of the world? This is according to a recent assessment, although there are variations across the region. There are fears this could lead to the extinction of species such as polar bears, and that it will change the way of life of the people living there. Quick Climate Quiz C – Twice as fast

D - UAE C - Kuwait B - Canada A - Australia Which country has the highest CO2 emissions per capita? The Carbon Dioxide Information Analysis Center figures: UAE metric tonnes of carbon per capita Kuwait , US - 5.4, Australia , UK If total greenhouse gas emissions are compared, some analysts say Australia comes out higher than the US. Quick Climate Quiz D - UAE E - USA

The big CO 2 emitters

ENERGY USE WorldWide Energy Consumption

Where does our energy come from? Share of total Primary Energy Supply in ,376 Mtoe IEA Energy Statistics

World Evolution of Total Energy production by Fuel type from IEA Energy Statistics

35.6% 41.6% Increasing percentage of Total World Energy used for Electricity Generation Quadrillion BTU Electricity is becoming more important

World Evolution of Electricity Generation by Fuel type from IEA Energy Statistics

ELECTRICITY Energy for Electricity Generation by Fuel Type, 2003, 2015, 2030

Electricity How much do we use? Total kwhrs 13 Trillion22 Trillion Population 6,004m7,541m Per capita kwhrs 2,1652,917 Electricity Use: International Energy Outlook 2002 Population: US Census Bureau

Focus on Electricity World Electricity Generation by Fuel

Coal Easy to find, cheap, but high emissions Steps toward increased efficiency: New Super-critical plant designs Gas turbine exhausts to heat boiler feedwater Increase in biomass co-firing Improvements in thermal efficiency

Technically exploitable capability (TWh/yr) 1999 generation (TWh) Hydropower - Regional Distribution Hydro Potential in 150+ countries Proven, advanced technology Often integrated with other developments Low operating costs, long plant life Extremely efficient conversion

Nuclear Little pollution Virtually 0 greenhouse gas Environmentally benign plants Nuclear shares of national electricity generation

Natural Gas Air Pollution from the Combustion of Fossil Fuels kg of emission per TJ of energy consumed Nat. Gas OilCoal Nitrogen Oxides Sulphur Dioxide Particulates Sources: U.S. Environmental Protection Agency; American Gas Association A Low CO 2 emitter Hydrogen fuel cells Steps toward increased efficiency: Combined-cycle power plants Acid gas re-injection

Oil Electricity generation by: Conventional Steam Combustion Turbine Combined-cycle Air, land and water pollution Solid waste burden

Solar Energy How much is available? The sun’s rays provide enough energy to supply 10,000 times the TOTAL energy requirement of mankind. So, how do we harness it? Solar Thermal Photovoltaic The ULTIMATE source.

Photovoltaic Possible materials to make PV cells CiGs Copper Indium Gallium Diselenide Polymers CdTe Cadmium Telluride Silicon Amorphous Thin Film Mono crystalline Multi crystalline Solar power market share by technology

The Chain Metallurgical Grade Silicon Electronic Grade Chunks Ingot Bars Wafers Modules “Sand” Strings Cells

Manufacturing Process Let’s start on the beach! It’s not good enough! We need % purity. Chemical companies produce metallurgical grade (99%) silicon. The starting point is mined quartz sand, SiO 2

Manufacturing Process Metallurgical Grade Silicon Silicon Dioxide is mined from the earth's crust, melted, and taken through a complex series of reactions that occur in a furnace with temperatures from 1500 to 2000 oC to produce Metallurgical Grade Silicon (MG-Si). Source - Wacker

Manufacturing Process Hydrochlorination of Silicon MG-Si is reacted with HCl to form trichlorosilane (TCS) in a fluidized-bed reactor. The TCS will later be used as an intermediate compound for polysilicon manufacturing. The TCS is created by heating powdered MG-Si at around 300 oC in the reactor. In the course of converting MG-Si to TCS, impurities such as Fe, Al and B are removed. Si + 3HCl -----> SiHCL3 + H2

Manufacturing Process Distillation of Trichlorosilane The next step is to distill the TCS to attain a high level of purity. At a boiling point of 31.8oC, the TCS is fractionally distilled to result in a level of electrically active impurities of less than 1ppba. The hyper- pure TCS is then vaporized, diluted with high-purity hydrogen, and introduced into a deposition reactor for the polysilicon manufacturing process.

Manufacturing Process Polysilicon Manufacturing Conversion of hyper-pure TCS back to hyper-pure Silicon in poly deposition bells. Thin U-shaped silicon slimrods heated to ~1100 oC. Part of TCS is reduced to Silicon that slowly grows over the slimrods to a final diameter of 20cm or more. Besides the reduction to Silicon, part of the TCS disproportions to the by-product SiCl4. Polysilicon has typical metal contamination of <1/100ppb and dopant impurities in the range of <1ppb. It is now suitable for further processing.

Manufacturing Process Polysilicon Manufacturing The process focus shifts to the silicon’s atomic structure. It must be tranformed into ingots with a singular crystal orientation (this is the primary purpose of Crystal Growing). Before the Polysilicon can be utilized in the Crystal Growing process, it must be first mechanically broken into a chunks of 1 to 3 inches and undergo stringent surface etching and cleaning to maintain a high level of purity. These chunks are then arranged into quartz crucibles which are packed to a specific weight; typically more than 100kg for 200mm crystals to be grown. The next step is the actual crystal growing process.

Manufacturing Process Crystal Growing The crystal growing process simply re-arranges silicon atoms into a specific crystal orientation. The packed crucible is carefully positioned into the lower chamber of a furnace (right). The polysilicon chunks are melted into liquid form, then grown into an ingot. As the polysilicon chunks reach their melting point of 1420 oC, they change from solid to hot molten liquid. Heat Exchange Method (HEM) is used to form crystalline structure.

Manufacturing Process Crystal Growing Computer Simulation of HEM Process

Manufacturing Process Ingot Sectioning The process in the furnace will see the molten liquid formed into an ingot, using a directional solidification system (DSS), that may be sectioned into silicon bars.

Manufacturing Process Ingot Sectioning The Ingot bricks are cut down …. Ingot sectioning sawCropping saw Bars

Manufacturing Process Wafer Production …. and sliced to create wafers. Wire Saw Wafers

Silicon Tube Graphite Die Molten Silicon Induction Coil edge-defined film-fed growth process, for small scale production. Manufacturing Process Alternative Crystal Growing

An innovative technique of producing silicon wafers for solar cells directly from metallurgical grade silicon material Manufacturing Process Alternative Wafer Production

Production line designed to produce photovoltaic solar cells with as-cut p-type wafers for starting material. Manufacturing Process From Wafers

2. Texturing………………………. 3. Junction formation……………. 1. Surface etch………………… Edge etch……………………… 5. Oxide Etch……..…………… Antireflection coating…….… Metalization……………..…….. 8. Firing……..…………………….. 9. Wafer/Cell Characterization Manufacturing Process Cell Production

. Surface Etch Removes saw damage (about 12  m on all sides). Texturing Roughens surface to minimise light reflection Manufacturing Process – Cell Production

. Junction Formation Phosphorous diffused into wafer to form p-n junction Diffusion Furnace Manufacturing Process – Cell Production

. Edge Etch Removes the junction at the edge of the wafer Wafer Holder Plasma Etch Station Manufacturing Process – Cell Production

. Oxide Etch Removes oxides from surface formed during diffusion Wafer Etch Station Manufacturing Process – Cell Production

. Anti-Reflection Coating A silicon nitride layer reduces reflection of sunlight and passivates the cell Plasma PECVD Furnace Manufacturing Process – Cell Production

. Metalisation Front and back contacts as well as the back aluminum layer are printed Screen Printer with automatic loading and unloading of cells Manufacturing Process – Cell Production

. Firing The metal contacts are heat treated (“fired”) to make contact to the silicon. Firing furnace to sinter metal contacts Manufacturing Process – Cell Production

Module Production

Market Size By 2010, there is realistic potential for $30bn in solar power system sales

Production Cost Improvements Thinner wafers mean greater efficiency in price AND performance

Price Trend Estimate of global average solar module prices US$/watt

Rising Oil Prices

Cost Breakdown Produced in Low labour cost area 10.5 % 2.6 % 8.9 % 78 % (Labour cost $2/hour)

Cost Breakdown Produced in High labour cost area 9%9% 12 % 10 % 71 % (Labour cost $10/hour)

Viability Over 2 billion people in the developing world have no access to electricity. For these people, PV is probably the most economical power source today. It is anticipated that within the next 5 to 10 years, PV will become cost competitive with traditional power sources in countries with extensive electrical infrastructure (like the US and Europe).

The Future Is Bright Example of cost recovery on an installation amortised over 25 years. Assumes an increase in fossil fuel costs of 5% pa. PV generated per kwh Fossil generated per kwh

Future Developments R&D is focused on increasing conversion efficiency and reducing cell manufacturing cost, to reduce electricity generation cost. Improved crystallisation processes for high quality, low-cost silicon wafers Advanced silicon solar cell device structures and manufacturing processes Technology transfer of high efficiency solar cell processes from the laboratory to high volume production Reduction of the silicon wafer thickness to reduce the consumption of silicon Stable, high efficiency thin-film cells to reduce semiconductor materials costs Novel organic and polymer solar cells with potentially low manufacturing cost Solar concentrator systems using lenses or mirrors to focus the sunlight onto small-area, high-efficiency solar cells

 Laser Grooved Buried Contact Layer  High Efficiency Si Cells  Currently up to 19% Efficiency  Production Efficiencies up to 17% AKHTER Improved Cell Efficiency

AKHTER Solar Lens Development Optical Design Polarisation effects and the effects of real draught angles and facet sizes. Lens Zones modelled as a series of annular cones.

Energy concentration achieved by new optical design onto a 20mm diameter detector, placed in the focal plane of the lens. AKHTER Solar Lens Development DETECTOR IMAGE: INCOHERENT IRRADIANCE

New optical design reaches 82% efficiency with a power distribution on the solar cell within a factor of 3. This reduces hotspot problems. Focal plane 135mm from back surface of lens. Lens 4mm thick with facets 2mm deep. 3 degree draft angle. Uses specialised optical materials AKHTER Solar Concentrator Design Characteristics

Computer controlled Dual Axis Tracking System Compatible with new concentrator technology Independent of sensors which usually result in maintenance and operational problems Plant operation may be monitored from anywhere in the world AKHTER Tracking System

Space requirement – 500m x 600m Producing 18Million Kilowatt hours per year Enough to meet needs of 10,000 Homes AKHTER 10MW Solar Plant

Akhter Solar Concentrator Plant

Professor Humayun A Mughal Chairman, Akhter Group PLC Thank you