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Wind and solar power systems design analysis and operation second edition download |
. Wind and solar power systems design analysis and operation second edition download
It is seen that DC-voltage ripple is reduced in a 9-phase system. This reduction, in addition to the higher ripple frequency in 9-phase allows for a smoother rectified DC voltage, hence reduced capacitance. Note that the 9-phase power electronics rectifier has three times the 3-phase converter legs; however, the phase current is reduced in the 9-phase system. This distribution of current to more legs results in better use of rectifier which results in improved losses for the rectifier, and improved packaging.
Rahim, Y. Say, M. Alger, P. Adkins, B. Kron, G. Yamayee, Z. Slootweg, J. Grauers, A. Chalmers, B. Springer, Thesis, McMaster University, Dekka, O. Beik and M. Beik, A. Dekka and M. For this reason, the turbine speed is stepped up using a gear drive. The system can be fixed speed or variable speed, as described in this chapter. As seen earlier, the value of Cp varies with the ratio of the rotor tip speed to the wind speed, termed as the tip speed ratio TSR.
Figure 6. The TSR and the power coefficient vary with the wind speed. The Cp characteristic has a single maximum at a specific value of TSR, around 5 in this case. Therefore, when operating the rotor at a constant speed, the power coefficient can be maximum at only one wind speed. However, for achieving the highest annual energy yield, the value of the rotor power coefficient must be maintained at the maximum level at all times, regardless of the wind speed.
The value of Cp varies not only with the TSR but also with the construction features of the rotor. Attaining Cp above 0. Whatever maximum value is attainable with a given wind turbine, it must be maintained constant at that value. Therefore, the rotor speed must change in response to the changing wind speed.
This is achieved by incorporating a speed control in the system design to run the rotor at high speed in high wind and at low speed in low wind. For given wind speeds V1, V2, or V3, the rotor power curves vs.
For extracting the maximum possible energy over the year, the turbine must be operated at the peak power point at all wind speeds. Operating the machine at the constant TSR corresponding to the peak power point means turning the rotor at high speed in gusty winds. The centrifugal forces produced in the rotor blades above a certain top speed can mechanically destroy the rotor.
Moreover, the electrical machine producing power above its rated capacity may overheat and thermally destroy itself. For these reasons, the turbine speed and the generator power output must be controlled. The peak power point moves to the right at higher wind speed. In between, it operates in one of the above three regions. Other times, it is off because wind speed is too low or too high. The constant Cp region is the normal mode of operation, where the speed controller operates the system at the optimum constant Cp value stored in the system computer.
Two alternative schemes of controlling the speed in this region were described in Section 4. To maintain a constant Cp, the control system increases the rotor speed in response to the increasing wind speed only up to a certain limit. When this limit is reached, the control shifts into the speed-limiting region. The power coefficient Cp is no longer at the optimum value, and the rotor power efficiency suffers. If the wind speed continues to rise, the system approaches the power limitation of the electrical generator.
When this occurs, the turbine speed is reduced, and the power coefficient Cp moves farther away from the optimum value. The generator output power remains constant at the design limit. When the speed limit and power limit cannot be maintained under an extreme gust of wind, the machine is cut out of the power-producing operation.
Two traditional methods of controlling the turbine speed and generator power output are as follows: 1. Pitch control: The turbine speed is controlled by controlling the blade pitch by mechanical and hydraulic means. The power fluctuates above and below the rated value as the blade pitch mechanism adjusts with the changing wind speed. This takes some time because of the large inertia of the rotor. This minimizes the undesired fluctuations on the grid.
Stall control: The turbine uses the aerodynamic stall to regulate the rotor speed in high winds. The power generation peaks somewhat higher than the rated limit and then declines until the cutout wind speed is reached. Beyond that point, the turbine stalls and the power production drops to zero Figure 6. In both methods of speed regulation, the power output of most machines in practice is not as smooth. Theoretical considerations give only approximations of the powers produced at any given instant.
For example, the turbine can produce different powers at the same speed depending on whether the speed is increasing or decreasing. This is important, as it determines all major components and their ratings. The alternative generator drive strategies and the corresponding speed control methods fall in the following categories. It naturally fits well with the induction generator, which is inherently a fixed-speed machine.
The speed match between the two is accomplished by the mechanical gear. The gearbox reduces the speed and increases the torque, thus improving the rotor power coefficient Cp. Under varying wind speed, the increase and decrease in the electromagnetically converted torque and power are accompanied by the corresponding increase or decrease in the rotor slip with respect to the stator. The wind generator generally works at a few percent slip. The higher value benefits the drive gear, but increases the electrical loss in the rotor, which leads to a cooling difficulty.
The annual energy yield for a fixed-speed wind turbine must be analyzed with the given wind speed distribution at the site of interest. Because the speed is held constant under this scheme, the turbine running above the rated speed is not a design concern.
But, the torque at the generator shaft must be higher. Therefore, it is possible to generate electric power above the rated capacity of the generator.
When this happens, the generator is shut off by opening the circuit breaker, thus shedding the load and dropping the system power generation to zero. The major disadvantage of one fixed-speed operation is that it almost never captures the wind energy at the peak efficiency in terms of the rotor coefficient Cp. The wind energy is wasted when the wind speed is higher or lower than a certain value selected as the optimum.
With the generator operating at a constant speed, the annual energy production depends on the wind speed and the gear ratio. It is seen that the annual energy yield is highly dependent on the selected gear ratio. For the given wind speed distribution in the figure, the energy production for this turbine would be maximum at the gear ratio of When choosing the gear ratio, it is therefore important to consider the average wind speed at the specific site.
The optimum gear ratio for the operation of the wind turbine varies from site to site. Because of the low energy yield over the year, the fixed-speed drives are generally limited to small machines.
The speed is changed by changing the gear ratio. The two operating speeds are selected to optimize the annual energy production with the expected wind speed distribution at the site. Obviously, the wind speeds V1 and V2 that would generate peak powers with two gear ratios must be on the opposite side of the expected annual average wind speed. In the specific example of Figure 6. In some early American designs, two speeds were achieved by using two separate generators and switching between the generators with a belt drive.
An economic and efficient method is to design the induction generator to operate at two speeds. The cage motor with two separate stator windings of different pole numbers can run at two or more integrally related speeds.
The pole-changing motor, on the other hand, has a single stator winding, the connection of which is changed to give a different number of poles. Separate windings that match with the system requirement may be preferred where the speed change must be made without losing control of the machine. Separate windings are, however, difficult to accommodate.
In the pole-changing method with one winding, the stator is wound with coils that can be connected either in P or 2P number of poles.
No changes are needed, nor are they possible, in the squirrel cage rotor. The stator connection, which produces a higher pole number for low-speed operation, is changed to one half as many poles for highspeed operation.
This maintains the TSR near the optimum to produce a high rotor power coefficient Cp. The machine, however, operates with only one speed ratio of For the higher pole number, the coils are in series. The resulting magnetic flux pattern corresponds to eight and four poles, respectively. The coil pitch of the stator winding is fixed once wound, but its electrical span depends on the number of poles. A coil pitch one-eighth of the circumference provides full-pitch coils for an 8-pole connection, two thirds for a 6-pole, and one half for a 4-pole connection.
Too narrow a coil span must be avoided. For a speed-ratio generator, a possible coil span is 1. In each case, the coil span factor would be 0. Using the spans near 1 and 0. Table The table shows the importance of keeping the battery fully charged on cold days. The cycle life vs. DoD for the Pb-acid battery is depicted in Figure The discharge rate influences the Pb-acid battery capacity, as shown in Figure The shorter the discharge time i.
The Pb-acid cell voltage is 2. Select the electrochemistry suitable for the overall system requirements. Determine the number of series cells required to meet the voltage requirement. Determine the ampere-hour discharge required to meet the load demand. Ampere-hour capacity of the battery is then determined by dividing the ampere-hour discharge required by the allowable DoD calculated earlier.
Determine the number of battery packs required in parallel for the total amperehour capacity. Determine the temperature rise and thermal controls required. Each cell in the battery pack is electrically insulated from the others and from the ground. The electrical insulation must be a good conductor of heat to maintain a low temperature gradient between the cells and also to the ground.
It accepts less energy when charged at a faster rate. Also, the faster the discharge rate, the faster the voltage degradation and lower the available capacity to the load. Because the battery design is highly modular, built from numerous cells, there is no fundamental technological limitation on the size of the energy storage system that can be designed and operated using electrochemical batteries. The cells will be recycled again after their year life.
The spinning energy reserve of the battery provides continuous voltage support and cuts down on blackout possibilities. The continuously monitored operating parameters are the battery voltage, current, and temperature. The charging timer is started after all initial checks are successfully completed. Charging may be suspended but not reset if it detects any violation of critical safety criteria. The timer stops charging if the defect persists beyond a certain time limit.
The bulk-charge and the taper-charge termination criteria are preloaded in the battery management software to match the battery electrochemistry and system-design parameters.
On the other hand, the Li-ion battery, being sensitive to overcharging, is charged at a constant voltage, tapering off the charge current as needed Figure Overcharging causes internal gassing, which causes loss of water in the Pb-acid battery and premature aging. The charge regulator allows the maximum rate of charging until the gassing starts. Then the charge current is tapered off to the trickle-charge rate so that the full charge is approached gently.
The charge current is then cut back in steps until the battery is fully charged. At this time, the charge current is further reduced to a trickle-charge rate, keeping it fully charged until the next load demand comes on the battery. This method, therefore, needs at least three charge rates in the charge regulator design.
The regulator is designed for only one charge rate. When the battery is fully charged, as measured by its terminal voltage, the charger is turned off by a relay. When the battery voltage drops below a preset value, the charger is again connected in full force.
Because the charging is not gentle in this method, full charge is difficult to achieve and maintain. An alternate version of this charging method is the multiple pulse charging. Full current charges the battery up to a high preset voltage just below the gassing threshold. At this time, the charger is shut off for a short time to allow the battery chemicals to mix and the voltage to fall.
When the voltage falls below a low preset threshold, the charger is reconnected, again passing full current to the battery. It uses no charge regulator. The battery is charged directly from a solar module dedicated just for charging. The charging module is properly designed for safe operation with a given number of cells in the battery. For example, in a V Pb-acid battery, the maximum PV module voltage is kept below 15 V, making it impossible to overcharge the battery.
When the battery is fully charged, the array is fully shunted to ground by a shorting switch transistor. The shunt transistor switch is open when the battery voltage drops below a certain value. The isolation diode blocks the battery that powers the array or shunt at night, as discussed in Section 9. Otherwise, the battery performance could suffer, life could be shortened, and maintenance would increase.
The temperature-compensated maximum battery voltage and the SOC can improve battery management, particularly in extreme cold temperatures. It can allow an additional charging during cold periods when the battery can accept more charge. The low-voltage alarm is a good feature to have, as discharging below the threshold low voltage can cause a cell voltage to reverse become negative.
The negative voltage of the cell makes it a load, leading to overheating and a premature failure. The alarm can be used to shed noncritical loads from the battery to avoid potential damage. Figure The most important is not to overcharge the battery. Any overcharge above the trickle-charge rate is converted into heat, which, if beyond a certain limit, can cause the battery to explode.
This is particularly critical when the battery is charged directly from a PV module without a charge regulator. In such a case, the array is sized below a certain safe limit.
As a rule of thumb, the PV array rating is kept below the continuous overcharge current that can be tolerated by the battery. Isolation Diodes: Not all battery cells degrade at the same rate due to manufacturing tolerances and difference in operating temperatures. One or more cells making one string of the battery may age at a higher rate and reach to a lower voltage than other strings connected in parallel. In such a case, the current sharing between parallel-connected strings could be uneven, or highly uneven to the point that the lowvoltage string could draw current inward as a load instead of sharing the load.
Such situation is highly undesirable and unsafe, as it may cause the battery to overheat. The remedy to avoid such an unsafe situation is to use isolation diode at the top of each battery string to block any reverse current.
Air Circulation: Battery when charging, discharging, or under trickle charge generates gases internally, which pressurizes the battery casing. If the battery is not sealed, like some lead-acid batteries some old Navy submarines may still have such batteries in operation , the battery room may collect such leaked gas to an unsafe concentration level for personnel safety or fire safety.
This energy can be converted from and to electricity with high efficiency. The flywheel energy storage is an old concept, which has now become commercially viable due to advances made in highstrength, lightweight fiber composite rotors, and the magnetic bearings that operate at high speeds. The flywheel energy storage system is being developed for a variety of potential applications, and is expected to make significant inroads in the near future.
The energy storage in a flywheel is limited by the mechanical stresses due to the centrifugal forces at high speeds. Small- to medium-sized flywheels have been in use for years. Considerable development efforts are underway around the world for highspeed flywheels to store large amounts of energy. The present goal of these developments is to achieve five times the energy density of the currently available secondary batteries. Two counter-rotating wheels are placed side by side where gyroscopic effects must be eliminated, such as in a city transit bus, train, or an automobile.
The allowable stress in the material places an upper limit on the rotor tip speed. Therefore, a smaller rotor can run at a high speed and vice versa. For this reason, the rotor, in all practical flywheel system designs, is a thin-rim configuration. The higher the ultimate strength of the material, the higher the specific energy. The lower the material density, the lower the centrifugal stress produced, which leads to a higher allowable speed and specific energy.
In addition to a high specific energy, the composite rotor has a safe mode of failure, as it disintegrates to fluff rather than fragmenting like the metal flywheel. TABLE The fiber-epoxy composite rim is made of two rings. The outer ring is made of high-strength graphite, and the inner ring of low-cost glass fiber. The hub is made of single-piece aluminum in the radial spoke form.
Such a construction is costeffective because it uses the costly material only where it is needed for strength, that is, in the outer ring where the centrifugal force is high, resulting in a high hoop stress. Conventional bearings are used up to speeds in a few tens of thousands rpm. Speeds approaching , rpm are possible only by using magnetic bearings, which support the rotor by magnetic repulsion and attraction.
The mechanical contact is eliminated, thus eliminating friction. Running the rotor in a vacuum eliminates windage. The magnetic bearing comes in a variety of configurations using permanent magnets and dynamic current actuators to achieve the required restraints. A rigid body can have 6 degrees of freedom.
The bearings retain the rotor in 5 degrees of freedom, leaving 1 degree free for rotation. The homopolar configuration is depicted in Figure From Avcon Inc. The electromagnet coils are used for stabilization and control.
The control coils operate at low-duty cycle, and only one servo-controller loop is needed for each axis. The servo-control coils provide active control to maintain shaft stability by providing restoring forces as needed to maintain the shaft in the centered position. Various position and velocity sensors are used in an active feedback loop. The electric current variation in the actuator coils compels the shaft to remain centered in position with desired clearances.
Small flux pulsation as the rotor rotates around the discrete actuator coils produces a small electromagnetic loss in the metallic parts. This loss, however, is negligible compared to the friction loss in conventional bearings.
In the flywheel system configuration, the rotor can be located radially outward, as shown in Figure It forms a volume-efficient packaging. The magnetic bearing has permanent magnets inside. The magnetic flux travels through the pole shoes on the stator and a magnetic feedback ring on the rotor. The reluctance lock between the pole shoes and the magnetic feedback ring provides the vertical restraint.
The horizontal restraint is provided by the two sets of dynamic actuator coils. The currents in the coils are controlled in response to a feedback loop controlling the rotor position. The electromechanical energy conversion in both directions is achieved with one electrical machine, which works as a motor for spinning up the rotor for energy FIGURE Two types of electrical machines can be used, the synchronous machine with variable-frequency converter or the permanent-magnet brushless DC machine.
The machine voltage varies over a wide range with speed. The power electronic converters provide an interface between the widely varying machine voltage and the fixed bus voltage. It is possible to design a discharge converter and a charge converter with input voltage varying over a range of 1 to 3.
This allows the machine speed to vary over the same range. That is, the low rotor speed can be one-third of the full speed. Because the energy storage is proportional to the speed squared, the flywheel SOC at low speed can be as low as 0.
Experience indicates that the polymer fiber composites in general have a longer fatigue life than solid metals. A properly designed flywheel, therefore, can last much longer than a battery and can discharge to a much deeper level. Flywheels made of composite rotors have been fabricated and tested to demonstrate more than 10, cycles of full charge and discharge. This is an order of magnitude more than any battery can deliver at present. The current requires a voltage to be applied to the coil terminals.
For storing energy in a steady state, the second term in Equation The resistance of the coil is temperature dependent. For most conducting materials, it is higher at higher temperatures. If the temperature of the coil is reduced, the resistance drops as shown in Figure In certain materials, the resistance abruptly drops to a precise zero at some critical temperature.
In the figure, this point is shown as Tc. Below this temperature, no voltage is required to circulate current in the coil, and the coil terminals can be shorted. The current continues to flow in the shorted coil indefinitely, with the corresponding energy also stored indefinitely in the coil. The coil is said to have attained the superconducting state, one that has zero resistance. In the U. The system demonstrated over one million charge-discharge cycles, meeting its electrical, magnetic, and structural performance goals.
Conceptual designs of large superconducting energy storage systems up to MWh energy for utility applications have been developed. The main components in a typical superconducting energy storage system are shown in Figure The superconducting magnet coil is charged by an AC-to-DC converter in the magnet power supply. Once fully charged, the converter continues providing the small voltage needed to overcome losses in the room temperature parts of the circuit components.
This keeps a constant DC current flowing frozen in the superconducting coil. In the storage mode, the current is circulated through a normally closed switch. The system controller has three main functions. If the system controller senses the line voltage dropping, it interprets that the system is incapable of meeting the load demand. The switch in the voltage regulator opens in less than 1 msec.
The current from the coil now flows into a capacitor bank until the system voltage recovers the rated level. The capacitor power is inverted into or Hz AC and is fed to the load.
The bus voltage drops as the capacitor energy is depleted. The switch opens again, and the process continues to supply energy to the load.
The system is sized to store the required energy to power a specified load for a specified duration. This is higher than that attainable by any other technology. In the superconducting energy storage system, a major cost is to keep the coil below the critical superconducting temperature. Therefore, they can be cooled by liquid nitrogen, which needs significantly less refrigeration power. As a result, numerous programs around the world have started to develop commercial applications.
The isentropic value of n for air is 1. Under normal working conditions, n is about 1. When air at an elevated temperature after constant-volume pressurization cools down, a part of the pressure is lost with a corresponding decrease in the stored energy. Electric power is generated by venting the compressed air through an expansion turbine that drives a generator.
The compressed air system may work under a constant volume or constant pressure. In constant-volume compression, the compressed air is stored in pressure tanks, mine caverns, depleted oil or gas fields, or abandoned mines.
One million cubic feet of air stored at psi provides an energy storage capacity of about 0. This system, however, has a disadvantage. The air pressure reduces as compressed air is depleted from the storage, and the electric power output decreases with decreasing air pressure.
One million cubic feet of air stored at psi provides an energy storage capacity enough to generate about 0. A variable-volume tank maintains a constant pressure by a weight on the tank cover. If an aquifer is used, the pressure remains approximately constant whereas the storage volume increases because of water displacement in the surrounding rock formation.
During electrical generation, water displacement of the compressed air causes a decrease of only a few percent in the storage pressure, keeping the electrical generation rate essentially constant. The operating-energy cost would include cooling the compressed air to dissipate the heat of compression.
Energy is also lost to the cooling effect of expansion when the energy is released. Compressed air power plants of MW capacities have also been built in Israel, Morocco, and other countries. Two MW plants, one in Germany and one in Alabama, have been in operation for more than a decade. Both these installations operate reliably, although on a single generator.
They occupy salt caverns created by dissolving salt and removing brine. The million-m3 mines can store enough compressed air to drive MW-capacity turbines. The Ohio power sitting board approved the proposal for the operation to start before A Sandia National Laboratory study found the rock structure dense enough to prevent air leakage and solid enough to handle the working pressures from 11 MPa down to 5.
The air from the mine after the expansion cooling is heated with natural gas to drive the turbines at an optimal temperature.
This operation would use less than one-third of the fuel of a gas-fired generator and would reduce the energy cost and emission levels. The Ohio system is designed with nine MW generators and uses 18 compressors to pressurize the mines. A minimum of MWh capacity was found necessary for this wind farm, and a MWh additional capacity was allowed to meet the losses during discharge with some margin.
Adapted from Enslin et al. They also conducted a parametric study with the storage capacity for potential applications in the 20 to MWh range. The results of this study are shown in Figure It shows that the Pb-acid battery is the least-cost option, followed by the pumped water, and then the compressed air systems.
These trades, however, are extremely site-specific. The nature of air storage and its cost e. However, the technology which can meet large power and energy storage needs in a variety of applications, small and large, is most likely to be the Lithium-ion electrochemistry.
This section therefore presents features of Lithium-ion batteries not covered earlier. A variety of rechargeable lithium-ion Li-ion batteries are widely used in numerous industrial, commercial, and consumer applications. They are used in small power range in portable electronics, medium power range in electric vehicles, and large power range in utility energy storage for grid stability and in large solar and wind energy installations to maintain power availability to the users at all times.
They are also increasingly used in military and aerospace applications. The basic performance features of the Li-ion battery depend on the cell type and its component design, but their typical values are in the following range Table One such Li-ion cell No.
Each No. Large cubical prismatic cells up to Ah are also available from other vendors, if desired for a compact design. Large batteries of any desired capacity can be assembled using numerous small cells in modules.
There is no real limit on the battery size as the design is highly modular. As shown in Figure This way, very large batteries up to MWh capacity have been built, tested, and placed in operation on some grid power substations.
Each such unit is 4. The battery is charged from the grid power at night to discharge back into the grid when the power demand exceeds the grid generation capacity, typically in the afternoon.
The Li-ion battery is now used in most new electrical vehicles made in the world. A safety issue of its exploding and causing fire due to an internal short has come to surface several times in the last few years, including in the Boeing Dreamliner planes in early The GM corporation and others have addressed this issue by developing ceramic-coated separators for lithium-ion cells. Such separators provide greater thermal stability than non-coated versions. The ceramic coating prevents the separators from shrinking at higher temperatures, thus minimizing the risk of a short in the cell.
There is no single energy storage technology that can meet all the desirable attributes for an application on hand, but a hybrid energy storage system can. For example, Chugach Electric Association in Anchorage, Alaska, has installed a hybrid battery and flywheel energy storage system for grid stabilization. The flywheel provides rapid injection of power to stabilize voltage and frequency and can deliver 18 MW-secs of energy within 1 millisecond. Riezenman, M. Wicks, F. DeWinkel, C.
Balachandran, U. Enslin, J. Schumacher, O. Device costs have declined to less than a tenth of those three decades ago, fueling an exponential growth in applications throughout the power industry.
No other technology has brought about a greater change in power engineering or holds a greater potential for bringing improvements in the future, than power electronic devices and circuits. In this chapter, we review the power electronic equipment used in modern wind and PV power systems. A common feature of these devices is that all are three-terminal devices, as shown in their generally used circuit symbols in Figure The two power terminals 1 and 0 are connected in the main power circuit, and the third terminal G, known as the gate terminal, is connected to an auxiliary control circuit.
In a normal conducting operation, terminal 1 is generally at a higher voltage than terminal 0. Because these devices are primarily used for switching power on and off as required, they are functionally represented by a gate-controlled switch shown in the last row in Figure The device in this state lets the current flow freely through it.
The characteristics of switching devices commonly available in the market are listed in Table The maximum voltage and current ratings along with unique operating features of transistors and SCRs commonly used in high-power applications, such as in wind and PV power systems, are listed in Table Thyristor technology has advanced dramatically into a variety of devices such as forced-commutated and line-commutated thyristors.
GTO and static induction thyristors SITHs get turned on by a positive pulse to the thyristor gate and turned off by a negative pulse. They offer good forced-commutation techniques.
Both have high flexibility and can be easily controlled. IGBTs are less common but could give good control flexibility.
MOSFETs are controlled by a gate voltage as opposed to other transistors controlled by a gate current and can be used at even higher switching frequencies but in low power ranges.
After meeting the various losses in the reaction, we get less than 1 V at the output terminals under load. The third section explores large-scale energy storage technologies, overall electrical system performance, and total plant economy while the final section explores ancillary power systems derived from the sun.
Focusing on the complete system rather than on a single component, Wind and Solar Power Systems: Design, Analysis, and Operation, Second Edition offers the most comprehensive reference to all aspects of modern renewable energy systems. It is also obvious that he is an experienced teacher, because the presentations are technically accurate, well organized, effectively paced, and appropriately targeted for the mid- to upper-level undergraduate student with reasonable technical exposure and interest.
I wish I could have had this book when I taught my own alternative energy classes to Mechanical Engineering undergraduates. Craig, Journal of Environmental Quality, American Electrical Power engineer with over 50 years of internationally recognized expertise in research, development, design, and education of advance high-power, high-voltage equipment and systems for land, ships and space.
Have authored over 50 research papers, 5 books, and coauthored two international handbooks. Previous page. Publication date. Print length. See all details. Next page. Review "Throughout the text, it is abundantly clear the author is a knowledgeable engineer with considerable experience in the diverse sciences and technologies that provide the foundations of wind and photovoltaic power generation.
About the author Follow authors to get new release updates, plus improved recommendations. Mukund R. Brief content visible, double tap to read full content. Full content visible, double tap to read brief content. Patel, PhD, PE, prof. Many developing countries have large areas falling in this category, and that is where the most PV growth is taking place, such as in India and China. The emerging thin-film and concentrating PV cells are expected to reduce the module prices substantially in the near future.
After the restructuring of U. Their reasoning is that the generation business has been stripped of regulated prices and opened to competition among electricity producers and resellers. The transmission and distribution business, on the other hand, is still regulated.
The American expe- rience indicates that free business generates more profits than regulated business. Such is the experience in the U. EPAct of Moreover, the renew- able power price would be falling as the technology advances, whereas the price of the conventional power would rise with inflation, making the wind and PV even more profitable in the future. Because overloaded transmission lines caused the blackout, and it would take decades before new lines can be planned and built, the blackout has created a window of opportunity for distributed power generation from wind and PV.
As most large-scale wind farms are connected to the grid lines, PV systems are expected to benefit more in distributed power generation growth. The Author Mukund R. Patel, Ph. Presently, he is a professor of engineering at the U.
Patel obtained his Ph. He is a fellow of the Institution of Mechanical Engineers U. Patel has presented and published about 50 papers at national and interna- tional conferences, holds several patents, and has earned recognition from the National Aeronautics and Space Administration for exceptional contribution to the photovoltaic power system design for the Upper Atmosphere Research Satellite.
He is active in consulting and teaching short courses to professional engineers in the electrical power industry. Patel lives in Yardley, Pennsylvania, with his wife, Sarla. Patel can be reached at. Sign up Sign in.
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