The Solar Energy Conversion Engineering Essay

The Solar Energy Conversion Engineering Essay

The suns energy can be converted to electricity to give us a changeless beginning of energy that can be tapped into without fright of power cuts, overly high electricity measures and to guarantee a clean and pollution free environment. This can be done with the aid of photovoltaic cells in solar power workss set up particularly for this intent. The solar power workss have solar panels that are made up of legion solar cells. A solar cell is a little disc made of a semiconducting material type of stuff like silicon french friess. They are attached to a circuit by electrical wires. As the sunshine hits the semiconducting material, Sun ‘s energy in the signifier of light gets converted into electricity that forms a circuit and flows through the wires. The solar cells can merely bring forth power in the presence of strong sunshine. When there is no light the solar cells stop bring forthing electricity.

Solar batteries are fast going popular as a manner of conventional auto fuel to assist in the preservation of our environment and cut down C footmark. It minimizes the opportunities of being caught on the manner with a dead battery and high measures for gasolene and other fuel. Green solar autos are being made popular by celebrated concern house like Toyota, Panasonic, Venturi and others to advance consciousness and make a favorable trade name image. Federal and province authoritiess besides encourage the usage of solar loanblend, eco friendly autos by originating revenue enhancement benefits.

Solar Energy Conversion

The theory of solar energy transition is a modern scientific discipline that came into being in 1970s. In order to provide to our of all time turning energy demands, assorted surveies have been undertaken in recent times to research agencies of developing efficient solar energy discoursing techniques. The sum of energy that comes on Earth from the Sun is of amazing quantum-in one second the Sun provides around 1017 Js of energy to Earth besides it is every bit surprising to cognize that the Sun provides every bit much energy to the Earth in one hr that humans need yearly. The rate at which the Earth receives solar energy from Sun is 1.2A A-A 105 terawatts whereas the production rate of energy on Earth by man-made techniques is simply 13TW. The quantum of solar energy though received by Earth is unprecedented but the same is non efficaciously used to provide the energy demands of the civilisation. The non-renewable beginnings of energy like fossil fuels are still used as a major beginning to fulfill the energy demands worldwide. Through the procedure of burning dodo fuels are turned into utile energy but they tend to bring forth assorted nursery gases and other pollutants doing certain jeopardies to the environment. Assorted facts about solar energy cited below makes it more appealing than any other energy beginning:

broad handiness

versatility

benign consequence on the environment and clime

Figure 1: Solar Panel used as a beginning of surrogate energy for mundane usage.

The untapped potency of the solar energy could be harnessed by transition of solar energy into electricity. Today assorted surveies on energy transition based on nano-materials focal point on such transition.

Solar Energy Conversion

Listed below are the three methods used for the transition of solar energy into electricity:

1. Solar Energy Cell

2. Solar Energy Collectors

3. Solar Energy Concentrators

Fig 2: An efficient Solar Cell giving up to 40 % efficiency developed by Spectrolab Inc.

Solar Energy Cells

The Solar Cells by and large known as photovoltaic cells are used to change over sunshine into electricity straight, and the phenomenon is known as the photovoltaic consequence. Photovoltaic batteries are made up of thin beds of semi-conducting stuff placed one above the other. Silicon is by far the most popularly used semi-conducting stuff that is used in photovoltaic cells. In recent times solar panels have proved their public-service corporation in both the residential solar power coevals every bit good as for public-service corporation scale power workss. When the surface of the cells faces the Sun, the negatrons absorb the solar energy in two different semiconducting materials which in bend creates the electric current.

Faculties is a term used to mention to an array of photovoltaic cells that are grouped together for the intent of making an energy flow and they are capable of keeping about 40 cells. In the procedure of bring forthing electricity for a edifice at least 10 such faculties need to be mounted together, the figure of faculties demands to be increased for bring forthing electricity for large buildings like power works. The Sarnia Photovoltaic Power Station in Canada is the universe ‘s largest photovoltaic works with a capacity of 80 MW.

Solar Energy Collectors

This procedure is used to heat the edifices in winters. First of all solar panels are installed on the roof of the edifice. These panels along with heating up the edifice besides heats up the H2O pipes being carried in it throughout thereby maintaining the H2O heated up inside the edifice. The solar energy is hence straight used to warm the H2O.

The two chief constituents of a solar H2O warming system are: solar aggregator and a storage armored combat vehicle. Storage aggregator is a level plated thin rectangular box confronting the Sun installed on the roof of the edifice. The solar energy heats up the absorber home base and in bend that heats up the H2O fluxing through tubings inside the aggregator.

Solar Energy Concentrator

Solar power can besides be converted into electricity indirectly through concentrated solar power ( CPS ) .Under this method, mirror constellations are used to change over the solar energy into electricity. Assorted concentrating techniques are available which include the followers:

Parabolic trough

Concentrating additive Fresnel reflector

Dish Stirling

Solar power tower

Fig 3: Parabolic Curved Mirrors

The parabolic trough technique is the most normally used technique to roll up the solar energy and utilize it to heat H2O. By utilizing this technique the sunshine is focused onto a receiving system pipe by utilizing parabolic curved mirrors. The receiving system pipe runs through the focal point of the curving surface. The working fluid in the pipes gets heated up and a conventional generator is used to bring forth electricity. The significance of this system lies in the fact that big country of sunshine is focused into a little beam by utilizing lenses and mirrors. The troughs in the aggregator are aligned on a north-south axis to fit the motion of the Sun from E to west throughout the twenty-four hours.

The 354 MW SEGS Concentrated solar power works is in California and is the largest power works to tackle solar energy in the universe. Other CSP ‘s include the Solnova Solar Power Station ( 150 MW ) and the Andasol Solar Power Station ( 100 MW ) ; both these power Stationss are in Spain.

In relevancy to this undertaking of planing a solar auto solar energy transition is utile for storage in batteries to be used to run a motor. For the constituents of a solar auto to map optimally, the converted electric energy has to be distributed to the assorted tonss from the motor. The beginning has to be connected to the tonss such as the ventilating fan, headlamps, wireless, splashboard gages, telemetry equipment, chief gulf relay and the horn. The current and voltage demands of the different tonss require foundation, protection from overload and shift.

Storage of Electricity

After the transition of the solar energy into electricity it becomes imperative to hold proper agencies to hive away it to hold uninterrupted supply of electricity even when the sunshine is non available. Broadly talking the solar electricity could be stored either through integrating with the grid of the public-service corporation company or supplying solar batteries to bank the electricity.

Grid Storage

This system of storage is used when electricity is being stored on a really big graduated table. The excess electricity generated in the extremum hours get stored in the grid which can be withdrawn whenever required.

Battery Storage

The demand for hive awaying the extra energy produced by the solar panels for subsequently usage necessitates the usage of solar batteries. The solar battery shops the extra charge and helps to power a solar driven motor on yearss when direct sunshine may non be available or even during the dark clip. Normally used types of batteries are the Lithium polymer, Lithium ion, Nickel-Cadmium, Nickel-Metal Hydride and the lead-acid batteries. The most efficient of these, nevertheless, are the Lithium polymer batteries. They store their electrolyte in an organic dissolver province and are non-inflammable and safe to utilize.

When long power outages from the grid are predicted so battery bank is used to hive away the electricity produced from the solar energy. This manner of storage is every bit easy as hooking up the batteries to the transmittal grid and the extra solar power can so be stored in the batteries. This is one of the most efficient ways to hive away power, because rechargeable batteries can hive away the extra electricity for a longer continuance of clip. When the solar-electricity is produced, it is sent to the batteries where it gets converted into chemical energy and is stored in a liquid signifier. At the clip of recovering the electricity from the battery, an electric charge is produced to trip a chemical procedure to change over energy back in the signifier of negatrons. Assorted types of batteries are available to hive away solar-electric energy and are used in different application countries:

Vanadium Redox Flow Battery

Under Vanadium Redox Flow battery electrical energy is stored in two armored combat vehicles of electrolytes or fluids that conduct electricity. Such batteries could be used as storage backup for a clip span of 12 hours. These batteries could besides be used in incorporating solar power in a residential vicinity or at several big industrial sites. At the clip of energy demand the liquid is pumped from one armored combat vehicle to another through a steady procedure after which the chemical energy from the electrolyte is transformed to electrical energy. During extremum periods when there is maximal sunshine this procedure gets reversed and the extra energy gets stored in the battery. The size of the armored combat vehicle and its capacity to keep the electrolyte influences the quantum of energy that could be stored in the battery.

Sodium-beta aluminum oxide membrane battery

Under the sodium-beta aluminum oxide membrane battery sulfur and Na are peculiarly used which serves the intent of bear downing and dispatching the electricity in/from the battery. The battery ‘s nucleus is made up of aluminum oxide dwelling of Na ions. The battery is built in cannular design and has the capacity to hive away tonss of energy in a little infinite. This battery is best suited for powering electric vehicles because of its high energy denseness, rapid rate of charge and discharge and short, powerful explosions of energy.

However, as the battery operates at high temperatures it has been suggested to modify the form of the battery in order to repair the safety issues and besides to better the efficiency.

Lithium-ion battery

By and large Lithium ion, or Li-ion batteries are used in family appliances and electric vehicles. These batteries are made up of different elements like Li, manganese and Co. These are best suited for transit applications because of their high energy and power capacity potency.The battery works when positively charged Li ions migrate through a liquid electrolyte, while negatrons flow through an external circuit, both traveling back and Forth from one side to the other. This motion creates and shops energy.

Lead-carbon battery

The Lead-carbon batteries are normally used as back-up generators and in cars. Assorted surveies have shown that the lifetime of the traditional lead-acid batteries can be improved by adding C in it. Besides, such lead-carbon batteries have high concentrated power which makes them suited for beginning for solar power. In a normal lead-acid battery, sulfuric acid reacts with the lead anode and cathode to make lead sulfate in the procedure of discharge. The procedure reverses during charge. With clip the battery ‘s nucleus gets filled up with lead sulfate due to crystallisation. This procedure of crystallisation can be prevented by adding C to the battery thereby heightening the life of the battery.

The pick of utilizing a peculiar battery from the above explained few depends upon the nature of application and the budget of the undertaking.

A aggregation of affiliated 2- , 6- , or 12-volt batteries that supply power to the works in instance of outages or low production of electricity is known as a battery bank. In order to bring forth the current these batteries are wired together and a series is formed thereby bring forthing 12- , 24- , or 48-volt strings. These strings are so connected together in analogue to do up the full battery bank. The battery bank supplies DC power to an inverter, which produces AC power that can be used to run contraptions. Factors like inverter ‘s input, type of battery selected sum of energy storage required determines the size of the battery bank.

At the clip of installing of new battery, it is suggested to look into its life rhythm and the figure of deep discharges it will be able to supply in future. Besides the thickness of lead home bases need to be checked upon as the life of battery depends upon the thickness of the home bases.

For intents of running an electrical motor powerful plenty to drive a solar auto the battery and solar cells should be connected in analogue to the motor accountant, so that both have the capableness to provide power to the motor accountant. The battery can besides hive away the extra power from the solar array. The electromotive force from the battery coach is distributed every bit between the battery, solar cells and motor accountant. A low electromotive force circuit supplies power to the horn, cockpit fan, signal visible radiations and back-up visible radiations. DC-DC convertors cut down the chief coach electromotive force to lower electromotive forces as per demands by feeding two branch circuits.[ I ]

Figure 4: MATLAB design of a DC electrical circuit

Care of the solar battery

The normal life of batteries is around 10-15 old ages irrespective of the sum of their use as the acid in the battery wears down the internal constituents of the battery. In order to maintain the battery working over its full life following patterns must be undertaken:

1. Deep discharging of batteries in perennial intervals must be avoided. The life of a battery is negatively correlated with the figure of times it is discharged i.e. the life-time of a battery gets shortened by the figure of times it has been discharged. Another manner to repair this job is by increasing the size of the battery bank.In order to back up deep discharge of batteries every twenty-four hours the size of battery bank must be increased.

2. Batteries must be stored at controlled temperatures. Rating for battery life is done merely for temperatures between 70°-75° . If batteries are kept in temperatures warmer than this it reduces their life significantly. An effectual manner to heat a battery storage unit is by utilizing inactive solar power, but the battery storage unit must besides be good insulated. Keeping the temperature of the battery storage unit below 70°-75° will non widen their lives to any important grade but will be given to diminish their lifetime. The other jeopardy of dismissed batteries is that they may stop dead up and explode so it is of import to keep sufficient charge on the batteries in cold conditions conditions.

3. Equal charge must be sustained in all the batteries. Though, by and large, the battery battalion may hold an overall charge of say, 84 Vs, some cells in the series may hold more/ less electromotive force than its neighbouring cells.

4. Inspection of batteries at regular intervals is besides required to maintain a path of escape as a consequence of swelling on the exterior of the battery, appropriate degrees of fluid for moisture cell batteries, and for maintain equal electromotive force.

The solar battery should hold a changeless electromotive force of about a 100 Vs to be able to power the solar auto engine. The battery battalion comprises of several faculties wired together. The higher electromotive force corresponds to better efficiency even though it requires a more complex array. The electronics commanding the power to the auto include peak power trackers, the motor accountant and informations transmittal system.