230 likes | 524 Views
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 H ² T ~ 0.5 H ² T k = constant, H = wave height (crest to trough) in meters, and T = wave period (crest to crest) in seconds. Overview.
E N D
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
Overview • 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? energy 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. work renewable
Wave Energy Conversion Systems (WECS) • 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.
Wave Energy Conversion Systems (WECS) • 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.
Wave Energy Conversion Systems (WECS) 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?
Which is it?1.Oscillating Water column? 2.Wave Surge/Focuser? 3. Float/Pitch Device? Wavegen created the “Limpet”… the world’s 1st wave power station. It is in Islay, Scotland.
Which system are these devices? Pelamis WaveRoller
WaveDragon None of the above! Salter Duck
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?
Types of energy in a fixed wave power generator Where in this diagram do each of the following energy types occur? • wave energy • mechanical energy • pneumatic energy • electrical energy
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 Wave Power: Benefit or Challenge?
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.
Kane‘ohe Marine Corps Base WET Project • 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 • Shoreline Conditions • Oceanographic Conditions • Infrastructure Impacts • Recreation Impacts • Public Safety • Cultural considerations Subsea Cable Installation
Possible Environmental Issues • Alien Invasive Species • Entanglement • Entrapment • Electromagnetic Radiation (EMR) • Electrical leakage • Heat generation and release • Noise Diver Working on Plate Installation for Biological Monitoring
Historic Preservation • structure eligible for listing in National Register of Historic Places • Cultural Consideration • Ancient Hawaiian Burial Ground Hawaiian Blessing of Site Cable and Vault Located Above Ground
Researchers found Environmental Advantages • No fuel • Absence of CO2 emissions, radiation, and particulate matter • No waste or disposal requirements • No 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 Anchor Box
Goals of WET in Hawai‘i • Develop and Validate Technology • Demonstrate reliability and cost effectiveness • Demonstrate feasibility of combining power from a multi-buoy array Anchor Installation