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.

Offshore Wind Energy Research

at

The National Renewable Energy Laboratory

Walt Musial

Principal Engineer

Manager Offshore Wind

National Wind Technology Center

OSW Innovation and Commercialization Symposium

July 11, 2014

2

National Renewable Energy Laboratory

2

3

DOE’s National Wind Technology Center (NWTC)

Primary wind technology center inside the National Renewable Energy Laboratory (NREL)

Established in1977

Approx. 150 staff on-site

Annual Budget approx. $40M

Partnerships with industry

Wind and Marine Hydrokinetic Technology

Modern utility-scale turbines

Pioneers in wind component testing

Blade Testing

Dynamometer drivetrain testing

Controls research turbines (CART)

Leadership in international standards

Leading the development of design and analysis codes

Offshore Wind Power 3 National Renewable Energy Laboratory

4

National Wind Technology Center Megawatt Scale Wind Turbines

Siemens 2.3 MW

DOE 1.5 MW GE • Model: GE 1.5-SLE • Tower Height: 80 m, Rotor Diameter: 77 m • DOE owned; to be used for research and education • Turbine commissioned Sept 2009

Siemens 2.3 MW • Model: SWT-2.3-101 • Tower Height: 80 m, Rotor Diameter: 101 m • Siemens owned and operated • Multi-year cost-shared R&D CRADA; aerodynamics and rotor performance • Turbine commissioned October 2009

Alstom 3 MW • Model: ECO 100 • Tower Height: 90 m, Rotor Diameter: 100 m • Alstom owned and operated • Multi-year Funds-In Agreement; testing, R&D • Turbine commissioned April 2011 - New Blades (106m Dia.) Feb. 2013

Gamesa 2 MW • Model G97 • Tower Height: 90 m, Rotor Diameter: 97 m • Gamesa owned and operated • Multi-year Funds-in Agreement; testing, R&D • Turbine commissioned November 2011 – Replaced Feb. 2013

Alstom 3 MW

Gamesa 2 MW

DOE 1.5 MW

5

New 5.8 MW Dynamometer Upgrade

6

NWTC Controllable Grid Interface (CGI) Facility

o CGI interconnected to 2.5MW and 5MW dynos

o Command voltage profiles to emulate real power-line faults

o 7MVA continuous with 28 MVA short circuit capacity

Dyno Motor 6MW (8000 HP)

Dyno Non-Torque

Loading NTL

Dyno Variable Frequency Drive VFD Test Article

Power Converter

Dyno Gearbox 75:1, 3-stage Test Article

Drivetrain

Test Article Transformer

CGI Housing

5 MW Dyno

7

Blade Testing Facilities

New Large Blade Test Facility:

• Boston, MA with Massachusetts

Technology Collaborative

• Static and Fatigue tests: blades up

to 90 m

• NREL has developed and patented advanced blade

testing

• NREL supports R&D blade testing for DOE and

industry

• Supporting development of new blade test facilities

worldwide

8

Massachusetts Blade Testing Facility

9

The Technology has changed significantly in 30 years

BLADE SHAPE…

2014: 53 m blade from SWT 2,3-108

1980: 5 m blade from Bonus 27 kW scaled to same size

Courtesy Kenneth Thomsen, Siemens

30 Years of Development Scaled to the same size: Lighter, Stronger, Longer, Quieter, Thinner, and Higher Energy Yield….

Average offshore wind turbine capacities, rotor diameters, and

hub heights are expected to continue to increase

10

0.5 0.5 0.5 0.6 0.6 2.0 1.9 2.0 2.2 2.5 3.0 3.0 3.0 3.2 2.8 3.1 3.9 3.5 4.2 3.9 4.5 5.1 -

20

40

60

80

100

120

140

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

1990 1995 2000 2005 2010 2015

Dis

tan

ce

(m

)

Rate

d C

ap

ac

ity (

MW

)

Weighted Average Capacity Weighted Average Rotor Diameter Weighted Average Hub Height

Graphic Source: NREL

Large Offshore Turbine Technology (5-10 MW)

Motivation

• Offshore economics favor larger machines

• O&M costs, electric distribution costs, specific energy production, installation cost, foundations costs all improve with turbine size

Challenges

• Large turbine enabling technology is needed

• Vessels and infrastructure are limited

Solutions

• Innovative deployment systems

• Ultra-long blades/rotors

• Down wind rotors

• Direct drive-generators (possible HTSC)

• Weight optimized wind turbines

• Special purpose vessels

Offshore Wind Power 11 National Renewable Energy Laboratory

XEMC Darwind

Offshore MET/Ocean Validation Tools

Challenges

• High cost of MET masts

• Marine boundary layer (wind shear, stability, and turbulence) is not well characterized

• Resource assessments rely on sparse measurements for validation

• External design conditions are poorly understood

Solutions:

• Remote sensing systems (LIDAR, SODAR)

• R&D to measure metocean conditions at sea

• Improved weather models

• Integration of multiple source data to validate resource models (e.g. satellites, met towers, etc)

• Improved forecasting

Floating wind LIDAR; The Natural Power Sea

ZephIR (from http://blog.lidarnews.com)

Offshore Wind Power 12 National Renewable Energy Laboratory

Wind Turbine Arrays Cause Wakes that Influence Energy and Operational Life

Turbine spacing is critical

13 Horns Rev Offshore Wind Plant

7D Spacing

14

High Definition Wind Plant Modeling -SOWFA

Simulator for Offshore Wind Farm Applications (SOWFA)

• Allows Wind Plant System Design

• Understanding of Fatigue Loading

• Deep Array Effects

• Optimized Wind Plant Control

Turbine Farm Array Mesoscale

Tools:

Scale:

WRF OpenFOAM FAST

SOWFA

Graphic Source: NREL

15

• Feed-forward control uses a LIDAR sensor to measure wind characteristics ahead of the turbine

• Feed-forward control loop improves controller performance by providing advanced warning of incoming gusts and turbulence

• Feed-forward controllers are being investigated for wind plant power control

• Field test implementations are now in progress

LIDAR/Feed-Forward Control

TURBINE FEEDBACK

CONTROLLER S

FEEDFORWARD CONTROLLER

S

-

Courtesy Dr. Lucy Pao, CU

16

16

Photo Source: Vattenfall

17

DOI and DOE Collaborate on Offshore Wind Strategy

DOE and DOI jointly announce A National Offshore Wind Strategy and over $200M in

Funding Opportunities in February 2011

Maryland’s proposed Wind Energy Area Lease Zones

Delineation Objectives:

1. Approximate balance in energy production potential between two development zones

2. Minimize wake loss potential between zones when developed

3. Maximize developable area in each zone considering buffers

Graphic Source: MEA

19

Technology Challenges for United States

Freshwater Ice Ice

Deep Water

Tropical Storms

Deep Water

International standards are being updated to address U.S. issues.

19

Graphic Source: NREL

20

Offshore Wind Technology is Depth Dependent

Offshore Wind Power 20 National Renewable Energy Laboratory

Graphic Source: NREL

21

There are three main classes of floating substructures

Spar Semisubmersible TLP

22

Offshore Wind Collaboration Opportunities

• Department of Energy is funding offshore demonstration projects with up to $168M

• The Bureau of Ocean Energy Management (BOEM) sponsors ongoing research through their Technology Assessment and Research (TA&R) program.

• Ongoing Industry partnerships

• International collaboration – (e.g. IEA)

23

23 Offshore Wind Power 23 National Renewable Energy Laboratory

Photo Credit: NREL