High Altitude Power Generation Correct.pdf

A PROJECT REPORT On

HIGH ALTITUDE WIND POWER GENERATION Submitted in partial fulfillment for the award of the degree of BACHELOR OF TECHNOLOGY In Mechanical Engineering Of A.P.IIIT, R.K.VALLEY,RGUKT By G.SREEDHAR R141078 P.SREEKANT R141248 V.MURALI R141447 S.BHASKAR R141545 Under the esteemed guidance of Mr K.DINESH REDDY Assistant Professor In Department of Mechanical Engineering

DEPARTMENT OF MECHANICAL ENGINEERING RAJIV GANDHI UNIVERSITY OF KNOWLEDGE TECHNOLOGIES RK Valley, A.P IIIT, Andhra Pradesh, December 2018

RAJIV GANDHI UNIVERSITY OF KNOWLEDGE TECHNOLOGIES RK Valley, A.P IIIT, Andhra Pradesh

CERTIFICATE This is to certify that the project work ‘‘ HIGH ALTITUDE POWER GENERATION’ ’ is a bonafide project work submitted by NAME OF THE CANDIDATES

ROLL NO

G.SREEDHAR P.SREEKANTH V.MURALI S.BHASKAR

R141078 R141248 R141447 R141545

in the department of MECHANICAL ENGINEERING in partial fulfillment of requirements for the award of Degree of Bachelor of Technology in “Mechanical Engineering” for the year 2018 - 2019.This work has been carried out under my guidance and has not been submitted the same for any University/Institution for award of any Degree/Diploma.

GUIDE Mr. K.DINESH REDDY Asst. Professor in Dept of Mech eng

HEAD OF THE DEPT.,Mech Mr. U.VENKATESULU Asst. Professor in Dept of Mech Eng

ACKNOWLEDGEMENT

We express our deep sense of gratitude to our guide Mr.K.DINESH REDDY, Assistant professor of Mechanical Engineering for his valuable suggestions and constant encouragement and evaluation throughout the period of the project work.

We would like to express our gratitude and reverence to our college RGUKT and all the facultymembers of Mechanical Department.

Last but not the least we would like to thank our parents for their constant support, energy,enthusiasm and inspiration for us to keep our morale high.

High Altitude Power Generation ABSTRACT: With the consciousness on green energy as well as the positive industrial growth outlook, the energy gap between the demand and supply has to be filled by renewable energy sources alone. This paved for a renewed interest in wind energy systems. Though there is a good research already been done in low altitude wind power extraction, the focus on high altitude wind energy systems is undermined. There is a tremendous scope as well as challenges associated with these systems. Our project investigates the paradigms, generator selection, generation control and transmission modes of high altitude wind energy systems. Also various aspects of feasibility, installation and control methods are critically reviewed.

High Altitude Power Generation Introduction:

wind: One of the five elements of nature . As we know earlier wind energy is free of cost and can be used for generation of electricity. Wind energy offers many advantages, which explains why it's one of the fastest-growing energy sources in the world. But the problem arises where we have to put extra efforts to constructing the wind turbine ,which is more complex in terms of construction and the capital cost is also very high.

Challenges for Traditional wind turbine: 1)Cost Analysis: The technology for a traditional wind turbine requires a higher initial investment than fossil-fueled generators. Roughly 80% of the cost is the machinery, with the balance being site preparation and installation. 2) Environmental Concerns: Although wind power plants have relatively little impact on the environment compared to fossil fuel power plants, there is some concern over the noise produced by the rotor blades, aesthetic (visual) impacts, and birds and bats having been killed (avian/bat mortality) by flying into the rotors.wind resource development may compete with other uses for the land, and those alternative uses may be more highly valued than electricity generation. However, wind turbines can be located on land that is also used for grazing or even farming.Good wind sites are often located in remote locations, far from cities where the electricity is needed. 4)Inability to produce power at difficult times: Over most of the land surface of The Earth, average wind speeds at surface are below 5 m/s, well below the velocity required for conventional ground-based wind turbines to operate. Hence traditional wind turbines can only be deployed in selected areas where surface winds regularly blow strongly and steadily. 5)Another important challenge with traditional wind turbine is that

“No wind no power Too much wind no power” *Wind resource development might not be the most profitable use of the land.Land suitable for wind-turbine installation must compete with alternative uses for the land, which might be more highly valued than electricity generation.

Need for High altitude power Generation: 1)According to a research that was made by Forbs says about electrification in India that “31 million Indian homes are still in dark”. So we have to look for alternatives.

Transition from normal wind turbine to High altitude wind turbine:

Figure 1

Speciality of HAPG:

250m above the surface winds blow more strongly and steadily providing usable wind speeds over most of the land area of The Earth. As a rule, the higher you go the wind speed increases. The challenge is how to access this wind to generate electricity.

This system reduces the need of gear box hence reducing the complexity & weight of the system. Due to generation of electricity by the motors on the Kite board while in trajectory, energy Kites are also called as on-board power generator. Here we are developing a wind turbine named as

Buoyant Airborne Turbine:

Structure of High altitude Power Generation System: 1)Tethered cables 2)Helium Balloon 3)Power Electronic converters 4)Ground station 5)System control Unit 6) high resolution camera 7)Small range mobile signal receiver Description and specifications of parts of the system of high altitude power generation:

1)Tethered cables:

The two main functions of the tether are to control and position the ABM at high altitudes and to transmit electrical power for on-board power generation systems and DBR devices. The material properties of the tether are important as a tether needs to withstand strong tensions due to the powerful, high velocity winds. Furthermore a tether is subject to strain due to ascending and descending the ABM load, elongating the tether. A high voltage tether is required to transmit the electricity to ground level, although the weight of the tether is an important constraint due to the effects of tether drag. So the material would allow HAWP technologies to operate at greater altitudes with lower drag and transmission losses. Material specifications: *copper conductor within a dyneema fibre. Tensile strength:11,000MPa The creep tensile strength, however, can be enhanced through the creation of copper alloys such as copper-silver. With alloys, a greater strength of up to 700 MPa can be achieved and, in some cases, even up to 1500 MPa. The disadvantage, however, is that the conductivity of such alloys decrease significantly.so here we will use copper having tensile strength 11,000MPa. Diameter:6.4mm - breaking strength 24.4KN Diameter :8mm breaking strength 39.9KN Diameter :9.5mm breaking strength 54.3KN

Optimum diameter will be equal to 9.5 mm even though the weight is some what high.

2)Helium Balloon:

A spherical balloon is designed to lift 22 kg weight rotor airborne. The spherical balloon, filled with helium gas is used to generate a static lift and tethered to the ground by means of a supporting tether. The designated altitude for the balloon is approximately 200 m. The air density at 200 m altitude is 1.167 kg/m3 while the ground temperature and the helium density are 25 °C and 0.1786 kg/m3 ,respectively. The static lift by 1 m 3 of helium is about 1.0 kg. The total weight of the tethered balloon system comes from three main components, namely:balloon, tether cable and payload, which also includes weight of the balloon fabric, pressure control system, rigging cables and patches. The weights are summarized in the table 1 . PARAMETERS

VALUES

1.Diameter

4.572 m

2.Volume

50.04 m3

3.Buoyant Force

513.33 N

4.Lift capacity

50.04 Kg

5.Helium Required

50040 L

Table 1 3) Generators & Power Electronic Converters: Converters are one of the key components of the HAWES. Since the wind potential is very high at high altitudes, generators with high power ratings are required. This necessitates either high voltage or high currents in the system As discussed in the earlier sections, the power to weight ratio is large when the generating voltage is medium. The transmission of the power can be done at higher voltages compared to the generating voltage but forces the usage of high insulation. In conventional wind energy system, several generators like induction generators, doubly-fed induction generators, synchronous generators, permanent magnet synchronous generators (PMSG) are proposed for extraction of wind power. While in HAWPG, most of the research is concentrated on the use of PMSG

Of all PMSGs, the ones with radial flux and centralized winding (for better cooling) are generally used[19]. The total weight of any electrical machine is the cumulative weights of conductor, insulation, rotor and stator frames and permanent magnet

4)The ground station: The ground station holds the tether, and is used as a resting place for the energy Kite, when not in flight. The ground station occupies less ground space and is significantly smaller than traditional wind turbines. The ground station is directly posed to the forces acting on Kite. The ground station strength actually decides the length up to which the Kite can be tethered. Here we have to Utilise a portable ground station built onto a trailer platform so that it can be deployed in any location. Winches on the ground station control both tether length and speed and correct alignment to prevent the tethers from tangling. The ground station also conditions the electricity produced before connecting to the grid.

The core is the system of automatic control of the kite flight,called KSU(Kite Steering Unit) the system comprises of 1)Actuation unit 2)Control software 3)Ground sensors

4)The system control unit:

The System Control Unit is designed to monitor the overall performance of the HAWP device through data transmission from on-board sensors. The main objectives of the System Control Unit is to maximize electricity generation and to ensure that all components are in good working condition and not exposed to excessive workloads or damaged by the high altitude conditions. Uses GPS system and gyroscope to monitor position of the wind turbine at that altitude. Kite design consist of various challenges like the rigidity of the material to sustain various types of forces acting on it, as the Kite rotates at a very high speed. The main force that the Kite has to withstand is the drag force. As the tether distance increases the drag force on the Kite increases too. As the drag force increases, power generation rate also increases whereas if this exceeds a limit may lead to minor instability of the system. However if such conditions exceeds their threshold then it cannot be controlled from ground station. To overcome the problem of long length of tethering & get efficient power generation at short tethering distance, multiple Kites are used as in fig 3. This concept indeed leads to significant reduction in tether drag loss as compared to a single wing system.

5)Mobile signal receiver: Mobile Signal Booster for 900-1800Mhz Dual Band GSM Antenna -PS1013SB Mobile signal boosters overcome these problems by amplifying weak cellular signals. Our cell phone signal boosters are able to pick up weak signals from a cell tower and transmit them to your cellular device, and then transmit a more powerful signal back to the tower Our mobile signal booster is specially designed for the “blind zones” or “no network zones” of hill stations and agency areas where the signal is very poor, or in spite of full mobile signals on the mobile phone, there is a break in voice leading to call clarity problem.

Specifications:

1.Coverage area 1000 Sq. Feet to 6000 Sq. Feet by using splitter & internal antennas using high hand models (upgradable to multiple rooms using accessories). 2.Reduce mobile phone output power, pro-long mobile battery life. Support multiuser & network operator. 3.High performance wireless internet speed. 4. LED performance & power indicator. 5. Overload protection circuit – protects cell towers from being overloaded Works on all generations of CDMA, GSM, and 3G/WCDMA 6)Surveillance Camera: The surveillance camera will be used for put some extra surveillance on the remote areas where it is very important for armed forces. Specifications: 1. Resolution:1280*720 2. Frames per Second:30

DESIGN AND ANALYSIS:

The main parameters that will affect the power generation and safety: Kite mass (kg) Characteristic area (m2 )

300 500

Lift coefficient Kite aerodynamic efficiency Diameter of a single line (m) Line density (kg/m3)

1.2 13 0.03 970

Line drag coefficient Minimum cable length (m) Air density (kg/m3)

1.2 850 1.2

Power Generation: The nominal power increases with the cube of wind speed and you will understand the attraction of reaching for the sky. Power=0.5*r*A*(V3) r=air density:Like air pressure the density of air decreases with increasing in altitude. Even though this is some disadvantage this can be overcome because of the wind speed. Numerical value: At 600 m the density of air would be 1.2kg/(m3). A = area: Here it means the area that swept by the turbine blades at that altitude Numerical value:-500m2 V= wind speed:Wind speed changes according to altitude, increasing where temperature increases. However, it does it not linearly but according the power law wind speed function: This is due to greater boundary friction with the earth which diminishes gradually as altitude increases. Numerical value: 17m/sec.

Figure 3 Power developed:P=(0.5*r*A*v3) P=(0.5*1.2*500*173) P=1.4MW

Efficiency calculations: Betz's Law:

According to Betz's law, no turbine can capture more than 16/27 (59.3%) of the kinetic energy in wind. The factor 16/27 (0.593) is known as Betz's coefficient. Practical utility-scale wind turbines achieve at peak 75% to 80% of the Betz limit. Analysis:This high altitude wind turbine can achieve the 90% of the betz’s coefficient.

EROEI: Energy returned on energy invested (EROEI or ERoEI), is the ratio of the amount of usable energy (the exergy) delivered from a particular energy resource to the amount of exergy used to obtain that energy resource. The average is 0.54 which is used in the calculation below. The capacity factor is higher than a turbine because high altitude winds (500 to 2000 m) blow more steadily than at the surface. Assumptions for a 3 MW power generation system: Capacity factor = 0.54 Lifespan = 20 years Power = 1.4 MW Mass of superstructure = 20 tonnes Energy produced during lifetime = 1.4*24*365.25*20*0.54 = 132541Mwh Energy required to create and to maintain machine = 20 tonnes * 16.6 MWh / tonne Numercal value=472 MWh ERoEI = 132541MWh / 332 MWh = 400 1.4 MW stem indicating a value of 400 which is incredibly high.

Calculating the forces on the ropes and speed of flight:

figure3 1. KE = (1/2)*m*V2 m = mass of air:around 29g/mol v = velocity of air, in this case wind speed:17 m/sec. Numerical value: KE=4190.5joules From this one can see that the area of the wind front will determine the mass of moving air. And since the KiteGen is operating at different altitudes the density of the air is an additional variable that will control the mass of air. These variables combine to give the equation for power. 2.Flight speed = wind speed * aerodynamic efficiency=(17*13) Numerical value:221 m/sec

As mentioned previously, much of the force on the ropes is generated by the efficiency of the aerofoil. Flight speed increases with wind speed and the aerodynamic efficiency. 3.Force on the ropes = (1/2 * flight_speed ^2 * lift coefficient * area of the wing * air density) F1=(0.5*2212 *1.2*28*1.2)=986.63KN 4.Force on the ropes= 1/2 * wind speed^2 * aerodynamic efficiency^2 * area of the wing * air_density (aerodynamic efficiency E=8-:-60 KiteGen wing =28. F2=(0.5*172*132*28*1.2)=820.5KN 5. Power = 1/2*ρ *A*V1^3 ρ = density A=swept area of the turbine blades V1 = wind speed at that altitude Power developed:-P=(0.5*1.2*500*173)=1.4MW We see here a crucial factor in that power increases by the cube of wind speed.

Risks: There are three obvious risks associated with this technology

1)The risk of crash:

The risk of crash can be solved by perfect design of the steel cables,maintaining the optimum pressure in the balloon and weight of the balloon.

2) The risk to aviation:

The risk to aviation can be solved by giving prior instructions to the department of aviation about this special arrangements.

figure 4

3)The risk to birds:

I think this is not so big problem why because no bird will fly in that much of height except some eagles. But If you consider normal wind turbines they are spoiling so many bird species. These are some extra benefits that can be obtained by this high altitude wind turbines.  Power to remote communities :The government of India itself says that  An elevated platform for telecommunications systems :In agency areas mobile internet connectivity is still a challange for the government.If we suceed in this project that problem can also be solved by putting some mobile network recievers.  An elevated platform for defence surveillance systems :Here if we put some extra efforts to this project it is easy for the department of defence that they can easily put their surveilence in agency areas.

5)Prevention of Problems:

Numerous storage systems exist, such as compressed air, battery arrays, flywheels or ultra-capacitors, which are selected dependent on the power output and operating altitude of the application. The purpose of these systems is to store energy when production exceeds demand and then reversely discharging this energy when demand exceeds production

Conclusion:

References: 1)Dyneema fibre,online https://www.dsm.com/products/dyneema/en_GB/scienceinnovation/science/scientific-cases/dyneema-carbon-composite.html 2)High Altitude Wind Power ReviewedJuly 4, 2016 by Euan Mearns http://euanmearns.com/high-altitude-wind-power-reviewed/,online 3)wind energy the facts https://www.wind-energy-the-facts.org/airborne-turbines.html 4)Design development of airbourne turbine by R. Lokesh Kannan , K. Sreekousalyadevi , S.M. Madhan Kumar, R. Karthick,V. Hariprasad,R. Arvind Singh,S. Jayalakshmi and N. Srikanth ,online https://www.researchgate.net/publication/311257901_Design_Development_of_ Airborne_Wind_Turbine/download 5)International Conference on Trends and Advanced Research in Green Energy Technologies, ICTARGET-2017’, 30 th & 31 st March, 2017A Review and Aspects of High Altitude Wind Power Generation by M. Uma Mahesh, Ayyarao SLV Tummala, and Ravikiran Inapakurthi,online https://www.researchgate.net/publication/321473577_A_Review_and_Aspects_o f_High_Altitude_Wind_Power_Generation/download 6)kite gen research,online http://www.kitegen.com/en/technology/details/ 7)Advantages and Challenges of Wind Energy https://www.energy.gov/eere/wind/advantages-and-challenges-wind-energy