Prepared by:
 Ahmed Al Busaidi, Oman Water Society
 Antonio Palacios, Inabensa Oman
 Eng. Narineh Simonian, Inabensa Oman

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Introduction to Solar technology and different types of systems to produce Electricity
Solar plants around the world
Diagram on solar price to generate Power
Operation and maintenance of solar plants
Solar best applications for the Sultanate of Oman.
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Solar power is the conversion of sunlight into electricity, either directly using photovoltaic (PV), or indirectly using concentrated solar power (CSP). CSP systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. PV converts light into electric current using the photoelectric effect.
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Photovoltaic Panels (PV)
Concentrated Solar Power (CSP)
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The term "photovoltaic" comes from the Greek φῶς ( ph ō s ) meaning "light", and from "volt", the unit of electro-motive force, the (volt), which in turn comes from the last name of the Italian physicist Alessandro
Volta , inventor of the battery (electromechanical cell ). The term "photo-voltaic" has been in use in English since 1849.
Photovoltaic (PV) cells are made up of at least 2 semi-conductor layers of Silicon. Silicon (Si) is the 8 th most common element in the earth.
One layer is doped by phosphorus (p) and becomes the negative layer, the other layer is doped with
Bore (B) to become the positive layer. Sunlight consists of little particles of solar energy called photons. when enough photons are absorbed by the panels the electrons migrate from negative layer to the positive one, and when the 2 layers are connected to an external load, the electrons flow through the circuit creating electricity .
PV panels
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PV panels

PV panels
1839 – First experimental demonstration of the photovoltaic effect by French physicist A.E.Becquerel .birth of the world's first photovoltaic cell.
1883- The first solid state photovoltaic cell was built, by American inventor Charls Fritts. The device was only around 1% efficient
1887 -Discovery of the photoelectric effect by Heinrich Hertz
1888 –The first cell based on outer photoelectric effect by Russian physicist Aleksandr Stoletov.
1946 - Russell Ohl patented the modern junction semiconductor solar cell
1954 - The first practical photovoltaic cell was developed at Bell Laboratories by Daryl Chapin, Calvin Fuller and
Gerald Pearson wiith 6% efficiency.
1954- 1960 - Mass production of the solar cells, and efficiency of Solar Cells improved from 6% to 14%. a cell that produced 1 watt of electrical power in bright sunlight cost about $250, comparing to $2 to $3 per watt for a coal plant.
1959 – America lunched Explorer 6 which featured large solar arrays resembling wings, which became a common feature in future satellites
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1960s- production of the cells with lower relative prices due to the new technologies of the production of the silicon layer.
1971 cell costs were estimated to be $100 per watt.
1973 Solar Power Corporation (SPC) was producing panels at $10 per watt and selling them at $20 per watt, a fivefold decrease in prices in two years.
1970s and 1980s -major oil companies started a number of solar firms, and were for decades the largest producers of solar panels. Exxon, ARCO, Shell, Amoco (later purchased by BP) and Mobil all had major solar divisions.
Today- further improvements have brought production costs down under $1 a watt
PV panels
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CSP
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Concentrated solar power (also called concentrating solar power, concentrated solar thermal, and
CSP) systems use mirrors or lenses to concentrate a large area of sunlight onto a small area.
Electrical power is produced when the concentrated light is converted to heat, which drives a heat engine (usually a steam turbine) connected to an electrical power generator or powers a thermochemical reaction.
The CSP plants consist of two parts:
• The one that collects solar energy and converts it to heat
• Another that converts the heat energy to electricity
CSP
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Trough systems use large, U-shaped (parabolic) reflectors (focusing mirrors) that have oil-filled pipes running along their center, or focal point. The mirrored reflectors are tilted toward the sun, and focus sunlight on the pipes to heat the oil inside to as much as 750°F. The hot oil is then used to boil water, which makes steam to run conventional steam turbines and generators.
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Power tower systems also called central receivers, use many large, flat heliostats (mirrors) to track the sun and focus its rays onto a receiver. The receiver sits on top of a tall tower in which concentrated sunlight heats a fluid, such as molten salt, as hot as 1,050°F. The hot fluid can be used immediately to make steam for electricity generation or stored for later use. Molten salt retains heat efficiently, so it can be stored for days before being converted into electricity. That means electricity can be produced during periods of peak need on cloudy days or even several hours after sunset.
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Dish/engine systems use mirrored dishes (about 10 times larger than a backyard satellite dish) to focus and concentrate sunlight onto a receiver. The receiver is mounted at the focal point of the dish. To capture the maximum amount of solar energy, the dish assembly tracks the sun across the sky. The receiver is integrated into a high-efficiency "external" combustion engine. The engine has thin tubes containing hydrogen or helium gas that run along the outside of the engine's four piston cylinders and open into the cylinders. As concentrated sunlight falls on the receiver, it heats the gas in the tubes to very high temperatures, which causes hot gas to expand inside the cylinders. The expanding gas drives the pistons. The pistons turn a crankshaft, which drives an electric generator. The receiver, engine, and generator comprise a single, integrated assembly mounted at the focus of the mirrored dish.
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Location: Gila Bend, Arizona, U.S.A.
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Output: 28O MW
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Technology: parabolic trough with storage
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Solar Field 1,920 acres
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Households supplied with clean energy: 70.000
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CO
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emissions eliminated each year: 475.000 tons
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Status: in operation since 2013
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The largest parabolic trough plant in the world
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6 hours of thermal energy storage using molten salts
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Solana´s production will be the equivalent of energy needed to serve 70,000 households and will prevent
475,000 tons of CO
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emissions per year, as compared to a natural gas plant.
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The construction of Solana created more than 2,000 new jobs and over 85 permanent jobs. Also, the construction and operation of the plant generated thousands of indirect jobs.
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From an environmental perspective, Solana provides Arizona citizens with clean, pollution and greenhouse gas free energy. At the same time, Solana reduces Arizona's need for fossil-fuel based energy generation, eliminating nearly 500,000 tons of carbon dioxide emitted into the atmosphere each year. These reductions will contribute to Arizona state goals for renewable energy deployment as well as national targets to reduce the negative impact of climate change.
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Location: Abu Dhabi, United Arab Emirates
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Output: 100 MW
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Technology: parabolic trough
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Solar Field: 741 acres
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CO
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emissions eliminated each year: 175,000 tons
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Status: Operation since 2013
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Highlights: Shams-1 incorporates state-of-the-art parabolic trough technology. Among other innovative features, highlights include the plant’s dry-cooling system and its auxiliary heating boiler
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The largest parabolic trough plant in the Middle East.
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Shams-1 represents an important step forward in introducing renewable energy in Abu
Dhabi, whose goal is to have 7 percent of its energy be from renewable sources by 2020.
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The plant prevents approximately 175,000 tons of CO
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emissions each year. This is equivalent to planting one and a half million trees or eliminating the use of 15,000 cars in a city like Abu Dhabi
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Location: Solucar Complex, Seville, Spain
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Output: 11 MW
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Technology: power tower
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Solar Field :148 acres
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Households supplied with clean energy: 5,500
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CO
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emissions eliminated each year: 6,000 tons
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Status: in operation since mid-2007
• the first commercial plant in the world to use tower technology
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Location: Pofadder, South Africa
Output: 100 MW
Technology: Parabolic trough with storage
Solar field: 310 ha
CO
2 emissions eliminated each year: 315.000 tons
Status: Under construction storage capability for 3 hours
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The various types of maintenance strategies for a PV plant include:
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Preventative Maintenance includes routine inspection and servicing of equipment to prevent breakdowns and production losses.
• Corrective or reactive maintenance addresses equipment breakdowns after the occurrence.
• Condition based maintenance (CBM) uses real-time data to prioritize and optimize maintenance and resources
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Over the course of time, dust collects on the PV panels significantly affects system efficiency. Panels must be cleaned regularly to minimize efficiency loss.
• System components must go through a thorough maintenance checklist at least once or twice per year .
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Panel cleaning is the most essential O&M issue in middle east
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Lack of available data in the region large scale Solar present challenges to run accurate costbenefit analyses of maintenance strategies.
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Sustaining adequate output power throughout the life of the PV panels due to operation under excess heat
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Dust and sandstorms significantly reduced the output of the plant
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Oman has a high ratio of “sky clearness”
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Extensive daily solar radiation ranging from:
1. 5,500-6,000 Wh/m2 a day in July
2. 2,500-3,000 Wh/m2 a day in January
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One of the highest solar energy densities in the world.
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Three sites with the greatest solar energy potential are:
(i) Marmul (ii) Fahud and (iii) Sohar
Of these, the best choice would be a solar plant situated at Marmul, which would produce an estimated
9,000MWh a year
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The key factor determining an area’s suitability is the Direct Normal Irradiance (DNI) value.
In Oman the DNI is 2,200 kWh per m2 per year. This could yield 19,404 kWh of electricity a year.
If 10 per cent of the land is found to be suitable, one study believes this could generate 7.6 million GWh a year, which is 680 times more than the total electricity supply in Oman in
2007 (11,189 GWh).
High potential to combined with desalination plants, could reduce fuel consumption required for this process to 5 per cent of what a conventionally powered plant uses.
The downside to this technology is that various formats have a high water consumption. A
100MW plant for example requires 4,800m3 a day to operate. This poses a problem in Oman where water is scarce.
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