Abstract: As today world need to make developing nation to developed nation which require huge industrialization, lighting up remote areas and village in developing countries that lead to make power generation as much as possible. The source of power generation till today 70% is about conventional, which may lead to decline our fossil fuel resources. The overcome for this, projects come from our dwindling energy supply and need for more low-emission energy technology. The hydrokinetic energy generation is one of them which have vast potential to extract energy from marine waves and runoff water. Hydrokinetic turbines advance day to day to overcome impact on marine biota and performance, efficiency etc. hydro kinetic turbines are more suitable for convert kinetic energy in the river and marine current. In this work we have run over the work and compare in hydro kinetic technology and provide a suitability of the turbine in particular environment field. We conceive mainly on the run of water hydro kinetic turbines which has most suitable for power channel, run off river, canal etc. and also we characterizes it based on parameter and performance.
Terms’hydro kinetic turbine, Tidal, horizontal axis, vertical axis
1 INTRODUCTION
Hydro electricity is the one of the form of renewable energy. It is well established till date so it has to be known as conventional form of hydro power. Today energy demand is increasing day by day and thus new concept of hydro energy conversion emerging .hydrokinetic energy conversion is one of these concepts to produce electricity from the runoff water in river, canal and power channel. It can be placed also on existing structures like barrages, bridges etc. Hydro kinetic technology is well suited to enhance the rural, and village areas where the huge construction do not require. This technology can be adopted individually easily and can run efficiently with less environmental impact. Energy can be extracted from the ocean and river currents by using submerged turbines, which are similar in function to wind turbines, capturing energy through the processes of hydrodynamic, rather than aerodynamic, lift or drag. Turbines can have horizontal, vertical or inclined axes of rotation [1]. The kinetic energy conversion in the river is most valuable research, which is invented by man that is natural flow is converted to the mechanical energy. It is nonconventional form of the energy source and has the future to fulfill the future energy need. The possibility of meeting our increasing energy demands with conventional hydropower seems very limited. The energy in flowing water current seems a good choice of renewables. Water provides the renewable energy option with a possibility of a continuous supply because this kind of energy does not need the storage [2]. The working principle of hydropower from water currents can be seen in Fig. 1.1. The working of a water current turbine is similar to that of a wind turbine. This concept is not new, and was investigated by different researchers since 1979[3].
Fig 1.1: Schematic view of hydrokinetic turbine system
[3].Today water power is the cheapest energy among all renewable energy and hydro kinetic energy conversion has no requirement of large civil structure that’s why it change the power generation concept still it has need research to numerous issue like rotor design, platform, generator for flowing on current etc. This work introduced all type of energy harvesting kinetic turbine which are theoretically and practically working and also introduced new energy conversion concepts which are suitable for water Current River as well as marine. This study also provides the knowledge about selection of hydrokinetic turbine for river, canals, power channel.
2 HYDRO KINETIC ENERGY CONVERSION PRINCIPLES
To estimate the power extraction capability of a (hydrokinetic energy extraction device) HEED, the method commonly used in the field is to use an ideal power calculation _Eq.2.1 developed for wind and tidal energy extraction. This is due to the similar nature of the energy extraction modes. Other researchers have also used this correlation since both systems involve fluids and either air-foil or hydrofoils [4, 5, 6]. The ideal power extraction principle from the hydro kinetic turbine is same as wind turbine because both devices are work on fluid energy. The energy conversion scheme is showing in Fig. 2.1. Mathematically power equation
2.1
Where, P is the power from HEED ?? is the density of fluid (water), A is the area of cross section of one HEED arm, Vi coefficient which is defined as [7]. is the initial velocity of
to the device. Cp is turbine power Where, V0 is outlet velocity of the device. It is an
2.2 approximation of the amount of energy that can be extracted through a wind turbine but a detailed analysis with blade shape and surface, and the corresponding fluid interactions, would give more accurate results [8]. Cp is a factor of the conservation of mass through a fluid stream tube approach. For an ideal turbine in an unbounded free stream, Cp tends to reach a Betz limit of 0.59. The Betz limit signifies the maximum theoretical limit of power from fluid based hydro kinetic turbine [9]. Fig 2.2 shows the power coefficient curves of HKT turbines. Technological advancement in tidal energy conversion, which employs the same principle as river turbines, is rather mature. RCECSs are being proposed as small power units with floating structures that can be easily placed in a river channel. In contrast, tidal turbines are generally larger in size, rigidly moored, and operate under periodic tide motion. Nevertheless, information on tidal energy systems is extremely valuable in understanding the river turbine technology [2].
Fig 2.1 hydro kinetic turbine components [2]
3 HYDRO KINETIC TURBINES
3.1 Literature review
Hydro kinetic turbine is newly growing turbine which is work on flowing current that convert the natural flow force to mechanical power and the electrical energy to grid or load. The various hydrokinetic energy technologies have some overlap but can be generally categorized as: axial and cross flow turbines, vortex shedding, and dynamic augmentation for localized increased extraction [9-10]. As in wind energy conversion, turbines are considered the system of choice. However, some non-turbine systems have been proposed (mostly at the proof-of-concept stage) and may become the innovative expectations in this new technological field [11]. The choice of turbine rotor configuration requires considerations of a broad array of
Fig 2.2: Power coefficient variation with their blade tip speed ratio [9]
technical and economic factors. As an emerging field of energy conversion, these issues become even more dominant for hydrokinetic turbines. A general classification of these turbines based on their physical arrangements is shown in Fig.3.1.
Fig. 3.1: Classification of hydro kinetic turbine rotors [11]
There are mainly three classification of HKT Based on rotation of the axis of shaft with respect to the flow of water i.e. Horizontal axis, vertical axis cross flow. The vertical axis turbines are same classified as wind turbine. The horizontal axis (alternately called as axial-flow) turbines
have axes parallel to the fluid flow and employ propeller type rotors. Horizontal axis turbines are common in tidal energy converters and are very similar to modern day wind turbines from concept and design point of view. Turbines with solid mooring structures require the generator unit to be placed near the riverbed or seafloor. Various arrangements of axial turbines for use in hydro environment are shown in Fig. 3.2 [12, 13, 14].
(a) Inclined axis (b) Rigid mooring
(c) Non submerged generator (d) Submerged generator
Fig.3.2: Horizontal axis kinetic turbines [11]
(a) Squirrel cage Darrieus (b) H- Darrieus (c) Darrieus
Inclined axis turbines have mostly been studied for small river energy converters. Most of these devices were tested in river streams and were commercialized in limited scales [15]. It is however not clear whether these latter devices are still being commercialized [11]. The cross flow turbines have rotor axes orthogonal to the water flow but parallel to the water surface. These turbines are also known as floating waterwheels. These are mainly drag based devices and inherently less efficient than their lift based counterparts. The large amount of material usage is another problem for such turbines [15, 16-17].
(d) Gorlov (e) Savonius
Fig. 3.3: Vertical axis kinetic turbines [11]
Darrieus turbines are the supreme bulbous options. Although use of H-Darrieus or Squirrel-cage Darrieus (straight bladed) turbine is very common, examples of Darrieus turbine (curved or parabolic blades) being used in hydro applications is non-existent [11]. Concert design and various parameters had been published in [3, 19]. The Gorlov turbine is another member of the vertical axis family, where the blades are of helical structure [19-22]. Savonius turbines are dragging type devices, which may consist of straight or skewed blades [22-25]. Hydrokinetic turbines may also be classified based on their lift/drag properties, orientation to up/down flow, and fixed/variable
(active/passive) blades pitch mechanisms. Different types of rotors may also be hybridized (such as, Darrieus Savonius hybrid) in order to achieve certain performance features [11]. Different types of simulation based hydro kinetic conversion technology are shown in Fig.3.4. As we know the marine turbine HCD technology based turbine some time differ from the river, canal and irrigation channel but some technology are same which can be used as run of river hydro kinetic turbine. Like multiple from Lunar, Three blade turbine, multiplied from UEK, multi blade from free Flow Power Tech, Horizontal and vertical Darrieus, Gorlov helical from Lucid Energy, Multiblade from Uni Southampton. Lunar energy offers a system which uses tidal current to produce electricity. The name of their system is Rotate Tidal Turbine (RTT). RTT is a fully submerged ducted turbine with the power conversion system inserted in a slot in the duct as a cassette [26]. Two
river projects have been applied by Verdant Power for river application RITE Project and CORE Project. RITE Project has been realized in New York East River. On this site, a new turbine of 5 m diameter has been installed. This turbine gives a capacity of 35 kW and rotates 32 rpm [26, 27]. The
Fig. 3.4: Different types of HCD technology [9]
dual UEK system is designed for stream velocities from 2 to 4 m/s for optimum usage. The turbine has a diameter of 3.3 m. This dual system gives approximately 75 kW at 2 m/s velocity [28]. Free Flow Power Technology (FFPT) has an integrated turbine generator system, which is called Smar Turbine Generator. The system has a ducted structure. This company is currently developing a project in the Mississippi River Basin. They planned 100 hydrokinetic sites on Mississippi, Ohio and Missouri Rivers [29]. Alternative Hydro Solution Ltd says that the Darrieus turbine is the best choice for small and medium river sites. The blade and the arms are made from Aluminium6063T5. Their turbines are available in four different diameters: 1.25, 1.5, 2 and 3m [30].The smallest turbine has a diameter of 1.25 and the height of 0.5 m [31]. Helical turbine has a same working principle as Darrieus turbine. Gorlov helical turbine consists of two or three-blade with helical form welded between two discs [19]. Blue energy technology produces the Davis Hydro Turbine, Which is a similar to H-Darrieus. The system has four fixed hydrofoil blades which are connected to a shaft that drives a variable speed electrical generator [32]. HydroVolts is a Flipwing turbine which are designed and developed by some engineering student at the University of Washington. The turbine can be constructed with 3, 4, 5 or 6 blades. The turbine blades spin with the water current, generating their force from drag [33].
4. ADVANCE TECHNOLOGIES IN HEED
Fig.3.4 shows various turbine technologies which are installed till today and these turbines are generating power in river and tidal based resources. Other turbine-based systems
(a) (b) (c)
Fig. 4.1(a): Rochester Venturi system from HydroVenturi (b) Paddle wheel (c) installed paddle wheel system [34]
(a) The River Bank Hydro Turbine (b) The Oscillating Cascade Power (c) Atlantis Energy’s Aquanator turbine at San
From Encore Clean Energy Inc. [34] System [34] Remo Australia [37]
Fig.4.2
can be categorized as follows: Cross-Flow turbines, Venturi
systems, and Gravitational-Vortex systems. In the non-turbine category we have: Flutter-Vane, Piezoelectric, and
Oscillating- Hydrofoil, Fan-Belt, and Paddle-Wheel systems. Some advancement in hydro kinetic turbines have been developed and investigated, there are following technologies are described as follows.
Venturi system fig.4.1 (a) uses Bernoulli’s principle to accelerate water through a choked duct. The pressure drop in the device drives turbines which can be placed above water or onshore. Venturi systems have no moving parts and no electrical components underwater, which may lead to robust low-cost systems with minimal maintenance costs, no visual impact, and no shipping-obstruction issues. One generator may be driven by several Venturi conduits giving a scalable system [34].
Floating paddle-wheel systems has Lots of superstructure and cost. In this system turbine is floats. Fig. 4.1(b) and (c) shows the Floating Power Station from Eco Hydro Energy
LTD, and Fig. 4.2(a) shows the River Bank Hydro Turbine from Encore Clean Energy Inc.
Flutter vane Oscillating Cascade Power System fig 4.2 (b) has a series of long, straight, symmetrical hydrofoils set in quartettes so that the blades move towards and away from each other in a paralleling approach. The pitch of the blades varies in such a way that they are alternatively attracted and repulsed by adjacent blades. A mechanical gear translates this oscillatory motion into rotational energy to drive a generator [35]. Atlantis Energy Aquanator uses a series of hydrofoils mounted on a belt sliding on an oval track 57 m across and 9 m high shown in fig 4.2(c). The structure is mounted completely underwater. When the tide shifts, the belt rotates in the opposite direction [36, 37].
Fig 4.3: The parachute HCD concept [38]
Fan belt hydro kinetic technology has been developed by Atlantis energy and this Aquanator turbine had installed at San Remo, Australia, in 2008. Fig. 4.2(c) shows another concept similar to the Aquanator, the 4P Aureola Spanish turbine. In terms of the HCD itself, the ‘parachute concept reported in DOI/ MMS-URL (2010). The parachute HCD concept fig 4.3, where the energy is captured by a barge moored in the current stream with a large cable loop to which the parachutes are fastened. The parachutes would be pushed by the current, and then closed on their way back, forming a loop similar to a large horizontal water wheel [38]. The Hydrovolt’s Flipwing (fig.4.4) is a cross-flow hydrokinetic turbine invented. it uses blades hinged on their outer edges so they naturally swing open to greatly reduce their resistance to the current on the upstream stroke, which has an effect on the loads exerted on the mooring system by a Seattle company [39]. This turbine is mostly suitable for river and canal installation.it has feature Simple construction, easy installation Level or spillway installation.
Fig 4.4: The Hydrovolts Inc.’s Flipwing turbine [39]
The unique, flying-saucer-shaped (fig 15) turbine is designed to sit on a riverbed. A set of ridged contours on top catch the current, causing it to spin and generate electricity [40].
Fig.4.5: Flying saucer shaped turbine [40].
The Minneapolis Company disclosed plans this month to try to raise $2.35 million from investors so that it can build the first full-scale prototype. Verterra Energy is among a flood of companies working to develop hydrokinetic or run-of- river turbines, which don’t require damming turbines, which don’t require damming or diverting water flow.
Tables 4.1: List River and tidal current hydrokinetic turbine manufacturers and their stage of technology development. [41]
Company
Location
Device
Stage of progress
Capacity
Blue Energy
CANADA
Blue Energy Ocean
Turbine
Scale model sea trials
250kW
C-Energy
NETHERLANDS
Wave Rotor
Scale model sea trials
30kW
Lucid Energy Technologies
LLP
GOSHEN, IN
Gorlov Helical
Turbine
Scale model sea trials
20kW
New Energy Corporation Inc.
CANADA
EnCurrent Turbine
Full scale prototype
5-250kW
Ponte di Archimedes
International S.P.A.
ITALY
Enermar
Scale model sea trials
25kW
Sea Power International AB
SWEDEN
EXIM
Scale model sea trials
48-72kW
Atalantis Resources corporation
UK
Nereus
Scale model sea trials
150 kW
Clean current Power System
CANADA
Clean current Tidal turbine generator
Full Scale Prototype
65 kW
Free Flow Power
GLOUSCESTER, MA
Small turbine Generator
Scale model Tank Testing
10 kW
Free flow 69
UK
Osprey
Scale model sea trials
1 kW
Hammerfest storm UK
UK
Tidal stream Turbine
Full scale prototype
300 kW
Hydro Coil Power Inc.
WYNEWOOD, PA
Hydro coil
Scale model Sea trials
20-40 kW
Hydro green Energy
HOUSTON, TX
Hydro+
commercial
35 kW
Maine Current Turbine
UK
Sea gen
Full scale prototype
300 -1200 kW
Natural Current Energy Service
HIGHLAND, NY
RED HAWK tidal turbine
Scale model sea trials
125 kW
Ocean Flow Energy
UK
Evopod
Scale model sea trials
1 kW
Ocean Renewable Power Company
FALL RIVER, MA
ORPC turbine Generating Units
Scale model sea trials
32 kW
Open Hydro
IRELAND
Open Centre Turbine
Full Scale prototype
150 kW
Robort Gordon University
UK
Swan turbine
Scale model sea trials
330 kW
SMD Hydro Vision
UK
TIDEI
Scale model tank testing
500 kW
Tidal Energy Pty. Ltd.
AUSTRALIA
Davidson Hill Venturi turbine
Scale model sea trials
Unavailable
Tidal Generation Ltd.
UK
Triton
Scale model tank testing
10 MW
Tocardo Tidal Energy Ltd.
NETHERLANDS
Tocardo Aqua 2800
Full Scale prototype
32 kW
University Of Strathclyde
UK
Contra rotating Marine turbine
Scale model sea trials
30 kW
Verdant Power
NY
Free Flow System
Full Scale Prototype
35 kW ‘ 1MW
Bio Power System
AUSTRALIA
Bio-Stream
Detailed Designed
250 kW
Pulse Generation Ltd.
UK
Pulse Hydro Foil
Scale model tank testing
100 kW
Vivace
US
Vortex Induced Vibration
Scale model Testing
Unavailable
Under Flow Water Wheel
US, ALSKA
Under flow Water Wheel
Conceptual
Unavailable
Minneapolis Company
US
Soccer turbine
Conceptual
Unavailable
(a) (b) (c)
Fig 4.6 Floating axis tidal turbine [38]
Table 4.2 Hydrokinetic Project Data with different aspects
RTT 20002000Ducted Axial 105400253.1<501490.8MCT2500Axial Propeller15500024183<300.7509(2 rotors)SMD hydro vision 10002 Blade Axial 1418824018.52.3-0.7537(2 rotors)UEK 400Ducted Axial Flow 7328457431.5438.6UEK 10000Ducted Axial Flow 6827864Verdand power RITE35.93 Bladed Axial 138161–52.20.719.6kobold (state of Messina )1503 Blade Darrieus 8215262.220130Mythos project5003 Blade Darrieus 24645.6122.512120Nenana, Alaska Hydrokinetic 25Horizontal Axis 4857762.5Eagle at yukon 61Horizontal 2596005721.156.812.5 (4 rotor)Iguigig plant at Kvichak river42Horizontal Axis Turbine465000651.51.392.421.2 12rotorWhitestone at Tanana593Horizontal Axis Axial Turbine1922002920.9796.7372(120 rotors)Water DepthCut in Speed Velocity (m/s)Frontal Area (m2)ProjectsProject Capacity (kW)Turbine Type`Project Cost / kWCapacity Factor (Cp)Rotor Dia. (m)
Inclined axis stream turbine concept shown in Fig. 4.6(a). It is similar to a vertical axis turbine. However, the turbine axis swings around the pivot on a supporting structure or on a float. The device can be installed on onshore structure or on a float as shown in Fig. 4.6(b) the array of moored turbines captures water stream energy efficiently as shown in Fig. 4.6(c). Floating axis tidal turbine is based on Floating Axis Wind Turbine (FAWT) concept [38]. Hydro kinetics turbine still immature in the many developing country but there is vast potential exist to develop hydrokinetic projects and installation. In table 4.1, various hydro kinetic turbines are shown with respect of capacity and their stage of development. Hydrokinetic technologies are still in the progressive phase, making it difficult to conduct precise economic analysis for future installations. Once more devices are built and installed; specific estimates for costs can be made. Although preliminary, economic analyses for several proposed hydrokinetic projects in Alaska have been conducted by the Electric Power Research Institute. Cost of some Alaskan project shown in table 4.2. At this stage, few hydro kinetic projects are developed in marine environment.
5 PROJECT DEVELOPMENTS AND LICENSING
First initiation has been taken by FERC to develop hydro kinetic projects in USA since 2002. FERC provided a detailed process for hydro kinetic pilot projects tailored to fulfill the needs of entitled in testing novel turbine, adding grid connection keeping mind the risk of adverse environmental effects. Under this process preliminary permits are issued up to three years. In this the agreement hydro kinetic electric generation facility should be provide 30-50 years under licensing. FERC also introduced a short term license for newly developed hydrokinetic turbine testing. The whole objective is to increase the measure of renewable energy contribution in rural and urban area and pilot process helps to it allowing developers to test new hydrokinetic technologies to find appropriate deployment of new technologies. The pilot project licensing ensures their environmental effects regularly inspect. Recently FERC has been issued the preliminary license to six hydro kinetic projects in river and Inland. The description of these projects is given in table 4.3.
Table 4.3 Preliminary licensed hydro kinetic projects
Project Name
Expiration Date
Issue Date
Authorized Capacity (KW)
Licensee
Waterway
STATE
Description
IGIUGIG RISEC
03-31-16
04-18-13
40
IGIUGIG VILLAGE COUNCIL
KVICHAK RIVER
AK
HydroKinetic-Inland Permit
NIAGARA COMMUNITY
06-30-16
07-06-11
1250
ECOSPONSIBLE, INC.
NIAGARA RIVER
NY
HydroKinetic-Inland Permit
NIAGARA COMMUNITY #2
06-30-16
07-06-11
1250
ECOSPONSIBLE, INC.
NIAGARA RIVER
NY
HydroKinetic-Inland Permit
MUSKEGET CHANNEL TIDAL ENERGY
07-31-14
08-02-11
4940
TOWN OF EDGARTOWN, MA
MUSKEGET CHANNEL
MA
HydroKinetic-Tidal Permit
TURNAGAIN ARM TIDAL
01-31-16
02-12-14
2200000
TURNAGAIN ARM TIDAL ENERGY
COOK INLET
AK
HydroKinetic-Tidal Permit
YAKUTAT ALASKA
12-31-15
01-30-13
750
RESOLUTE MARINE ENERGY, INC.
GULF OF ALASKA
AK
HydroKinetic-Wave Permit
6 CONCLUSIONS
The river current and tidal current energy conversion system technology is perhaps at its embryonic stage. Various recent reports indicate that many devices are gradually entering into the execution phase but some of the technologies are well established in different sites and
generating power in remote villages. In this article hydro kinetic conversion technology has been recited with a prominence on indicating the current developments in research and development inventiveness.
6 CONCLUSIONS
The river current and tidal current energy conversion system technology is perhaps at its embryonic stage. Various recent reports indicate that many devices are gradually entering into the execution phase but some of the technologies are well established in different sites and generating power in remote villages. In this article hydro kinetic conversion technology has been recited with a prominence on indicating the current developments in research and development inventiveness. This work shows that the wanders of river are one of the appropriate renewable resources to generate hydro energy. Small scale hydropower is a renewable energy source with low generation cost and high efficiency. Decisive growth of hydropower can increase the clean energy resource and decrease the emission of greenhouse gases, which is supportive to start a sustainable energy system and sustain the socio ‘ economic development. Based on the various study of hydro kinetic technology and their deployment steps the following conclusion has been made.
7 ACKNOWLEDGEMENTS
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