Emerging Technologies In Ocean Kinetic & Enhanced Geothermal Energy Days 2012: Many Paths for Sustainable Energy Michael Robinson, PhD NREL’s National Wind Technology Center February 23, 2012 NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy operated by the Alliance for Sustainable Energy, LLC

DOE Technology Readiness Level (TRL) Technology Status TRL 1 - Basic Research TRL 2 - Applied Research TRL 3 - Critical Function or Proof of Concept Established TRL 4 - Laboratory Testing/Validation of Alpha Prototype Component/Process TRL 5 - Laboratory Testing of Integrated/Semi-Integrated System TRL 6 Prototype System Verified TRL 7 - Integrated Pilot System Demonstrated TRL 8 - System Incorporated in Commercial Design TRL 9 - System Proven and Ready for Full Commercial Deployment National Renewable Energy Laboratory Innovation for Our Energy Future

Geothermal & Ocean Hydro-Kinetic Resource Potential Emerging Renewable Technology World Resource Estimate (TWh/Year) US Resource Estimate (TWh/Year) Enhanced Geothermal --- 778,000,000 (8)** Wave Energy 29,500 (1) 2,640 (3) Tidal Current Energy 7,800 (1) 525 (4) River Current Energy  --- 110 (6) Ocean Current Energy 43,800 (7) 5 (5)* Electricity Demand by 2030 12,000 (1) 4,586 (2) --- No Published Estimate Available * Extractable Estimate 10-15% ** Extractable Estimate 20% (1) An International Vision for Ocean Energy IEA OES October 2011 (2) EIA Annual Energy Outlook 2012 (3) Mapping & Assessment of the US Ocean Wave Energy Resource, EPRI 2011 (4) DOE Mapping Assessment Project, 2011 (5) DOE 1980 Estimate; 2012 DOE Update assessment in Progress (6) NYU 1986; 2012 DOE Update Assessment in Progress (7) Ocean Current Energy Potential on the U.S. Outer Continental Shelf, MMS 2006 (8) Impact of Enhanced Geothermal Systems (EGS) on the United States in the 21st Century, MIT 2006 National Renewable Energy Laboratory Innovation for Our Energy Future

Enhanced Geothermal Systems (EGS) Enhanced Geothermal Innovation Conventional geothermal limited by the number of naturally occurring reservoirs near the surface Heat, Permeable Rock, Water EGS technology creates a permeable energy reservoir by hydroshearing rock along existing fractures and using pumped fluid for energy extraction Energy Extraction Potential Function of Reservoir Size, Temperature & Fracture Surface Area Energy delivery potential four orders of magnitude greater than total domestic energy demand Innovations Required Through R&D Drilling technology – enabling access to deeper, hotter regions in high grade formations Power conversion technology – improving heat transfer performance leading to an order of magnitude improvement in reservoir performance and power conversion efficiency Reservoir technology – increasing production flow rates and heat removal efficiencies in fractured rock Technology Maturity RD&D Stage – TRL Level 2-3 for subsurface technology development Technical barriers & obstacles can be overcome with R&D investment 40 GW wind US; 240 GW worldwide 3 GW geothermal; 11 GW worldwide National Renewable Energy Laboratory Innovation for Our Energy Future

National Renewable Energy Laboratory Innovation for Our Energy Future Ocean Wave Technologies Technology Development Approaches Overtopping Technology – both wave height and surge, wave energy collected into a central basin and released though a low head hydro turbine Point Absorber – Buoy motion relative to a floating or fixed bottom reference drives a hydraulic or electric actuator producing energy Oscillating Water Column – Wave motion increases & decreased water level in a contained reservoir thereby driving air through a conventional air turbine producing electricity Wave Surge – Drag collector moves with the wave surge driving a hydraulic actuator that can be collected and/or direct coupled to an electric generator Floating Attenuator – Sectioned floating structure linked by hydraulics; wave motion drives hinged Wave Dragon - Overtopping OPT Point Absorber Oceanlinx Oscillating Water Column motion between sections that can pressurize a hydraulic reservoir and/or is direct coupled to an electric generator Pelamis Floating Attenuator Oyster Wave Surge Technology National Renewable Energy Laboratory Innovation for Our Energy Future

National Renewable Energy Laboratory Innovation for Our Energy Future Tidal & Current Turbine Technologies Technology Development Approaches Oscillating Hydrofoil – Current flow over the airfoil creates lift driving the attached piston which in turn drives a generator or hydraulic accumulator. At the end of the stroke, the blade pitches creating lift in the alternate direction to complete a cycle. Horizontal Axis Turbine – Flow through the rotor, ocean current or river, drives an electric generator to produce electrical power; derived from HAWT wind turbine technology utilizing many of the same design tools. Vertical Axis Turbine – Flow through the rotor, ocean current or river, drives an electric generator to produce electrical power; derived from VAWT wind turbine technology. Mounted parallel to the water utilize the highest flow rate. OPT Point Absorber Engineering Business Limited ”Stingray” SMD Hydrovision Verdant Power Free Flow Power Oyster Wave Surge Technology Marine Current Turbines Ltd. Ocean Renewable Power Company Verdant Power National Renewable Energy Laboratory Innovation for Our Energy Future

National Renewable Energy Laboratory Innovation for Our Energy Future Barriers to Marine & Hydrokinetic Commercialization Technology in the early stages of development and demonstration Wide variety of technology options – over 40 different development efforts in the US & many more internationally No clear “winners or losers” to focus resources on design optimization & development Significant maturation ranges with TRL’s from 1 to 6 Device functionality and associated risk require validation Modeling & analysis tools in their infancy Cost & performance data derived from commercial and pre-commercial prototype demonstration projects do not exist Initial technology design costs as high as 70 – 100 ¢/kWh, an order of magnitude too high to be competitive with existing generation Significant capital investment required to pass through the four technology development stages: 1) Controlled tank & tow test at scale, 2) Scaled prototype test & verification, 3) Full scale pre-commercial prototype test & validation, 4) Small demonstration projects of multiple units Environmental & Permitting Lack of data on environmental risks hamper early demonstration & deployment Uncertainty in achieving permitting and high cost of meeting EA process National Renewable Energy Laboratory Innovation for Our Energy Future

National Renewable Energy Laboratory Innovation for Our Energy Future Marine & Hydrokinetic Future Prospects Many of the current barriers to deployment are identical to the early days of land based wind technology development. Development of international standards for the design, development & deployment of MHK are in process through the IEC (TC 114) Federally sponsored test facilities in the UK have reached 100% capacity (EMEC) and have transitioned to full commercial operation Various international federal programs are providing incentives for early commercial development and demonstration Significant investment in test facilities South Korea is also heavily investing with 2 Tidal Power Stations built and a third underway EU Goal for Ocean Energy is 3.6 GW of generating capacity by 2020 and to reach 188 GW of installed capacity by 2050 Investments by DOE are quantifying the US domestic wave, tidal and ocean current resources for development Advanced tools, models, and materials to maximize efficiency and ensure survivability are under development at the National Laboratories MHK reference model effort will develop benchmark cost and performance for various technologies and assess technology cost reduction pathways Identification of critical cost drivers will inform DOE strategy for developing up to 15% of domestic electricity generation from wave, tidal and river resources by 2030 FERC issued a pilot commercial license to Verdant Power’s 30 MW RITE Project Goal: Reduce COE to $0.06/kWh by 2030 National Renewable Energy Laboratory Innovation for Our Energy Future

National Renewable Energy Laboratory Innovation for Our Energy Future Summary Enhanced Geothermal Systems Significant Resource Potential – Four Orders of Magnitude Greater Than TOTAL Domestic Energy Demand. TRL Level 2-3; Primarily Subsurface Technology Development Required LCOE Prediction is Premature; Expected to be at least Consistent With and/or Lower Than Conventional Geothermal Technology Marine Hydro-Kinetic Technology Supplying a Significant Percentage of the World’s Total Electricity Demand is Possible TRL Levels Vary from 1-6; Wide Variety of Technology Options Being Developed Early LCOE Estimates at Pre-Prototype Level range from 70 – 100 ¢/kWh Significant Room for Innovation and Associated Cost Reduction Through Learning Curve Effects Field Deployment & Validation Critically Needed to Validate Technology Pathways Development Trajectory Consistent with the Performance Enhancements & Cost Reductions Experienced by the Wind Industry National Renewable Energy Laboratory Innovation for Our Energy Future

Questions? Mike Robinson, PhD Senior Technology Advisor US Department of Energy Wind & Water Program Contact Information: Phone: 303-679-1365 Email: mike.robinson@ee.doe.gov NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy operated by the Alliance for Sustainable Energy, LLC