Wave Energy Technology. Why explore wave power in Hawai‘i? Wave Energy Levels (kW/m of Wave Front) Formula used to calculate this Power (in kW/m) = k

Wave Energy

Technology

Wave Energy

Technology Ka Hana ‘Imi Na‘auao – A Science Careers Curriculum Resource Go to: www.cds.hawaii.edu/kahana Ka Hana ‘Imi Na‘auao – A Science Careers Curriculum Resource Go to: www.cds.hawaii.edu/kahana

Why explore wave power in Hawai‘i?Why explore wave power in Hawai‘i?

Wave Energy Levels (kW/m of Wave Front)Formula used to calculate this Power (in kW/m) = k H² T ~ 0.5 H² T

k = constant, H = wave height (crest to trough) in meters, and T = wave period (crest to crest) in seconds

Wave Energy Levels (kW/m of Wave Front)Formula used to calculate this Power (in kW/m) = k H² T ~ 0.5 H² T

k = constant, H = wave height (crest to trough) in meters, and T = wave period (crest to crest) in seconds

OverviewOverview

What is wave power? Wave energy

conversion systems (WECS)

Types of energy Physics of water power Benefits &

Challenges Wave Energy

Technology (WET) in Hawai‘i

What is wave power? Wave energy

conversion systems (WECS)

Types of energy Physics of water power Benefits &

Challenges Wave Energy

Technology (WET) in Hawai‘i

PowerBuoy

What is Wave Power?What is Wave Power?Wave power is the ________ of ocean surface

waves and the capture of that energy to do useful _______ - including electricity generation, desalination and the pumping of water.

Wave power is a form of __________ energy. Tidal power and ocean currents are other sources of ocean hydro-electric power.

Wave power is the ________ of ocean surface waves and the capture of that energy to do useful _______ - including electricity generation, desalination and the pumping of water.

Wave power is a form of __________ energy. Tidal power and ocean currents are other sources of ocean hydro-electric power.

energy

work

renewable

Wave Energy Conversion Systems (WECS)


1. Oscillating Water Columns (OWC)

- generate electricity from the wave-driven rise and fall of water in a cylindrical shaft. The rising and falling water column drives air into and out of the top of the shaft, powering an air-driven turbine.

1. Oscillating Water Columns (OWC)

- generate electricity from the wave-driven rise and fall of water in a cylindrical shaft. The rising and falling water column drives air into and out of the top of the shaft, powering an air-driven turbine.

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.



2. Wave Surge or Focusing Devices

- These shoreline devices, also called "tapered channel" or "TAPCHAN" systems, rely on a shore-mounted structure to channel and concentrate the waves, driving them into an elevated reservoir. Water flow out of this reservoir is used to generate electricity, using standard hydropower technologies.

2. Wave Surge or Focusing Devices

- These shoreline devices, also called "tapered channel" or "TAPCHAN" systems, rely on a shore-mounted structure to channel and concentrate the waves, driving them into an elevated reservoir. Water flow out of this reservoir is used to generate electricity, using standard hydropower technologies.





3. Floats or Pitching Devices - These devices generate electricity from the bobbing or pitching action of a floating object. The object can be mounted to a floating raft or to a device fixed on the ocean floor.

3. Floats or Pitching Devices - These devices generate electricity from the bobbing or pitching action of a floating object. The object can be mounted to a floating raft or to a device fixed on the ocean floor.



Archimedes Wave Swing

Which is it?1.Oscillating Water column?

2.Wave Surge/Focuser? 3. Float/Pitch Device?




are needed to see this picture. QuickTime™ and aTIFF (Uncompressed) decompressor








Wavegen created the “Limpet” … the world’s 1st wave power station. It is in Islay, Scotland.

Wavegen created the “Limpet” … the world’s 1st wave power station. It is in Islay, Scotland.



Which system are

these devices?

Which system are

these devices?



WaveRoller







Pelamis





Salter Duck

WaveDragon





None of the above!None of the above!

The Physics of Hydro-Electric Power

The Physics of Hydro-Electric Power

Key physics concepts: energy, power & work

What is Bernoulli’s Principle? (hint: think about conservation of energy)

How might engineers apply it to wave energy?

Key physics concepts: energy, power & work

What is Bernoulli’s Principle? (hint: think about conservation of energy)

How might engineers apply it to wave energy?

Types of energy in a fixed wave power generator

Types of energy in a fixed wave power generator

Where in this diagram do each of the following energy types occur?wave energymechanical energypneumatic energyelectrical energy

Where in this diagram do each of the following energy types occur?wave energymechanical energypneumatic energyelectrical energy



Wave Power: Benefit or Challenge?

Wave Power: Benefit or Challenge?

Portable, modular design

Noise Pollution Cost-saving

potential Maintenance Site specifications

Portable, modular design

Noise Pollution Cost-saving

potential Maintenance Site specifications

Abundance of resource

Appearance of device

Marine life effects Fishing & recreation Installation &

development cost Coastal erosion Sustainability

Abundance of resource

Appearance of device

Marine life effects Fishing & recreation Installation &

development cost Coastal erosion Sustainability

Hawaii’s PowerBuoy™Hawaii’s PowerBuoy™Cylindrical, Steel Buoy

Diameter - 4.5 to 5 meters.

Length – 12 to 20 meters.

Mass – 35 to 55 tons.

Operates 1.0 - 4.0 meters below surface.

Average System Output:

20 kW

Peak Output: 45-50 kW

Mooring:Rigid spar buoy with universal joint at

base.

Deadweight anchor rock bolted into the substrate provides up to 100-ton holding force.

Cylindrical, Steel BuoyDiameter - 4.5 to 5 meters.

Length – 12 to 20 meters.

Mass – 35 to 55 tons.

Operates 1.0 - 4.0 meters below surface.

Average System Output:

20 kW

Peak Output: 45-50 kW

Mooring:Rigid spar buoy with universal joint at

base.

Deadweight anchor rock bolted into the substrate provides up to 100-ton holding force.

Kane‘ohe Marine Corps Base WET

Project

Kane‘ohe Marine Corps Base WET

ProjectThe PowerBuoy is

low-cost, efficient, and readily deployable electric power that can reduce costs at Kane‘ohe Marine Corps Base & similar naval sites

The PowerBuoy is low-cost, efficient, and readily deployable electric power that can reduce costs at Kane‘ohe Marine Corps Base & similar naval sites

Subsea cable installation

Issues KMCB had to address

Issues KMCB had to address

Shoreline Conditions Oceanographic Conditions Infrastructure Impacts Recreation Impacts Public Safety Cultural considerations

Shoreline Conditions Oceanographic Conditions Infrastructure Impacts Recreation Impacts Public Safety Cultural considerations

Subsea Cable Installation

Possible Environmental Issues

Possible Environmental Issues

Alien Invasive Species Entanglement Entrapment Electromagnetic

Radiation (EMR) Electrical leakage Heat generation and

release Noise

Alien Invasive Species Entanglement Entrapment Electromagnetic

Radiation (EMR) Electrical leakage Heat generation and

release Noise

Diver Working on Plate Installation for Biological

Monitoring

Hawaiian Blessing of Site Cable and Vault Located Above Ground

Historic Preservationstructure eligible for listing in National Register of Historic Places

Cultural ConsiderationAncient Hawaiian Burial Ground

Researchers found Environmental

Advantages

Researchers found Environmental

Advantages No fuelAbsence of CO2 emissions, radiation, and

particulate matterNo waste or disposal requirementsNo danger of spillage or other environmental

damage No negative impact on marine life

can encourage growth Live coral areas avoided

Minimal aesthetic impact

No noise pollution

No visual pollution

No fuelAbsence of CO2 emissions, radiation, and

particulate matterNo waste or disposal requirementsNo danger of spillage or other environmental

damage No negative impact on marine life

can encourage growth Live coral areas avoided

Minimal aesthetic impact

No noise pollution

No visual pollutionAnchor Box

Goals of WET in Hawai‘iGoals of WET in Hawai‘i Develop and

Validate Technology

Demonstrate reliability and cost effectiveness

Demonstrate feasibility of combining power from a multi-buoy array

Develop and Validate Technology

Demonstrate reliability and cost effectiveness

Demonstrate feasibility of combining power from a multi-buoy array

Anchor Installation

Documents

Wave Energy Technology. Why explore wave power in Hawai‘i? Wave Energy Levels (kW/m of Wave Front) Formula used to calculate this Power (in kW/m) = k