Effects of Hydrokinetic Turbines

Effects Of Hydrokinetic Turbines On Aquatic Life: Effects Of Hydrokinetic Turbines On Aquatic Life: TURBINE PASSAGE AND FISH BEAHVIORTURBINE PASSAGE AND FISH BEAHVIOR

Steve Amaral, Greg Allen, and George HeckerALDEN Research Laboratory, Inc.

Lucid Energy Technologies

1st Annual MREC Technical Conference

What have we learned from conventional hydro?

Effects of Hydrokinetic Turbines on Aquatic LifeEffects of Hydrokinetic Turbines on Aquatic LifeTurbine Passage and Fish Behavior

Theoretical estimation of strike probability and mortality using established models adapted to hydrokinetic devices

Laboratory studies: rigorous data and definitive answers

What have we learned from conventional hydro?What have we learned from conventional hydro?Turbine passage bio‐criteria

Cada et al. 1997

What have we learned from conventional hydro?What have we learned from conventional hydro?Turbine passage bio‐criteria ‐ CAVITATION

Formation of gas bubbles caused by reduction in pressure at or below vapor pressure.

Gas bubbles collapse when they enter regions of higher pressure.

Pressure waves from the violent collapse of gas bubbles can injure fish.

If water pressure does not drop below 60% of ambient pressure, cavitation will not occur.

May be a potential source of injury/mortality to fish passing through hydrokinetic turbines (DOE 2009).

http://wayneandlayne.com/tag/hydraulics/

What have we learned from conventional hydro?What have we learned from conventional hydro?Turbine passage bio‐criteria – SHEAR

Shear stresses sufficient to injure fish may occur near turbine rotors/blades (Cada et al. 2007).

Bio‐criteria for damaging levels of shear have been identified for conventional hydro turbines.

These data are applicable to hydrokinetic turbines; information on shear levels (magnitude and extent) needs to be developed for each turbine design.

Guensch et al. (2002); Nietzel et al. (2000)

What have we learned from conventional hydro?What have we learned from conventional hydro?Turbine passage bio‐criteria – PRESSURE

Hydrokinetic turbines do not experience extensive and rapid changes in pressure which have been shown to damage fish during passage through conventional hydro turbines.

If pressure‐related injury and mortality occur, they likely will be associated with cavitation areas.

Abernethy et al. (2001)

What have we learned from conventional hydro?What have we learned from conventional hydro?Turbine passage bio‐criteria – BLADE STRIKE

Primary mechanism of fish injury and mortality at many hydro projects.

Strike probability depends on blade spacing, rotational speed, relative velocity of fish to blade, and fish length.

Recent studies have demonstrated that blade strike survival can be greater than 90% at strike speeds up to 40 ft/s (12.1 m/s).

Little difference in mortality rates among typical teleost (boney) fishes.

Blade strike survival is affected by:‐ Blade shape‐ Blade thickness‐ Impact speed‐ Fish length

Numerical modeling has been used to evaluate effects of leading edge shapes on flow patterns and fish impact (EPRI 2008).

Semi‐circular shape provided optimal fish deflection.


EPRI (2008)

Fish L = 10 inches; Blade t = 0.38 inches; V = 24 ft/s

Fish L = 6 inches; Blade t = 6 inches; V = 24 ft/s


EPRI (2008)

TOTAL (96hr)SURVIVAL

Strike Speed (m/s)

2 3 4 5 6 7 8 9 10 11 12 13

Adju

sted

Tot

al S

urvi

val (

%)

40

50

60

70

80

90

100

0.751.001.754.009.6025.00

ApproximateL/t Ratio


EPRI (2008)

Theoretical estimation of blade strike probability Theoretical estimation of blade strike probability and mortalityand mortality

Theoretical models for predicting strike probability are well established for conventional hydro turbines (Von Rabon 1957; Monten 1985; Solomon 1988; Bell 1991; Turnpenny 1992, 2000; Ploskey and Carlson 2003; Hecker and Allen 2005)

The more recent studies have incorporated strike mortality rates to predict turbine passage survival (assuming other sources of mortality are inconsequential)

NOAA Fisheries has accepted the results of a predictive approach for an endangered species at a conventional hydro project.

These models can be modified and applied to hydrokinetic turbines to predict strike probability and survival rates.


Strike Probability

PS = n (Lsinα) N / (60Vr)

Where:n = rpmN = number of bladesL = Fish LengthVr = Radial Velocity

Strike Mortality

PMS = KM n (Lsinα) N / (60Vr)

Where:KM is % mortality from strike

Hecker and Allen (2005)


Hecker and Allen (2005)

Conduct highly‐controlled flume studies to calculate estimates of turbine survival and injury rates for multiple species and size groups and turbine operating conditions.

Laboratory studies: providing rigorous data Laboratory studies: providing rigorous data and definitive answersand definitive answers

Observe fish behavior as they approach and interact with operating turbines.

Laboratory studies: rigorous data and definitive answersLaboratory studies: rigorous data and definitive answersDetermining Turbine Passage Survival

Release marked fish directly upstream of operating turbine and force them to pass through blade sweep.

Known release and recovery numbers for multiple replicate trials.

Record video of release and fish behavior as they approach operating turbine.


Collect fish downstream with minimal stress and handling‐related injury.

Examine for immediate mortality, injuries, and scale loss.

Hold live fish for 96‐hrs after turbine passage to assess latent mortality.

Species

Mean Length (mm)

ImmediateSurvival(1 hr; %)

TotalSurvival

(96 hr; %)

Smallmouth Bass69 98.2 97.3

155 92.6 89.6

American eel249 100.0 99.6

431 100.0 98.2

Sturgeon 103 98.3 97.0

Alewife 76 95.4 93.7

Rainbow trout

38 97.6 96.7

85 95.3 94.7

172 90.9 89.3

Coho salmon 102 95.4 93.3

Test multiple species and size classes.

Use control groups to determine handling and test related injury and mortality.

Calculate precise and accurate estimates of turbine passage survival for selected turbine designs.

ACT Pilot-Scale Turbine Survival Data

Alden Research Laboratory (2003)


80.0

82.0

84.0

86.0

88.0

90.0

92.0

94.0

96.0

98.0

100.0

0.0 25.0 50.0 75.0 100.0 125.0 150.0 175.0 200.0

Fish Length (mm)

Imm

edia

te S

urvi

val (

%)

40 ft/240 rpm RBTrout at BEP80 ft/345 rpm RBTrout at BEP40 ft/240 rpm RBTrout off BEP40 ft/240 rpm Sturgeon at BEP40 ft/240 rpm Coho Salmon at BEP40 ft/240 rpm SMBass at BEP40 ft/240 rpm Alewife at BEPStrike Eq. with Ka (40 ft/240 rpm)Strike Eq. with Ka (80 ft/345 rpm)

ACT Pilot-Scale Turbine Survival Data


Normal-speed Video High-speed Video

40 ft head; 175 mm rainbow trout


Effects on fish behaviorAvoidance or attraction?

Ability to escape passage through blade sweep.


Avoid conducting redundant studies by using information available from conventional hydro research.

Eliminate or significantly reduce the need and cost of labor intensive and logistically difficult field studies.

Resource and regulatory agencies provided with data and information they need to make informed decisions on aquatic resource impacts.

Development of Hydrokinetic TurbinesDevelopment of Hydrokinetic TurbinesAlleviating Concerns and Moving Forward

Benefits of Literature Review, Blade Strike and Mortality Prediction Models, and Biological Flume Studies:

EPRIAldenConte Anadromous Fish Research LaboratoryNew Energy (Encurrent vertical axis turbine)Lucid Energy Technologies (Gorlov‐type turbine)Canada Department of Fisheries & Ocean Alaska Energy AuthorityAlaska Power & TelephoneNorthwest Territories Power CorporationGovernment of the Northwest TerritoriesAurora Research InstituteIndian and Northern Affairs Canada

EPRI -led team has received DOE funding for desktop studies and flume evaluations with at least two hydrokinetic turbine designs

New Energy Corporation

Lucid Energy Technologies

Development of Hydrokinetic TurbinesDevelopment of Hydrokinetic TurbinesAlleviating Concerns and Moving Forward

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Effects of Hydrokinetic Turbines

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