1

Research on wind

power in the built

environment

C.P. (Case) van Dam,

Bruce White, Scott Johnson,

Daeseong Kim, Henry Shiu, Matt Seitzler,

Rob Kamisky, Charles Turner

Urban Wind Roundtable

San Francisco

March,16 2011

2

Outline

! UC Davis/CWEC overview

! Atmospheric Wind Tunnel

! UC Davis projects

1. San Francisco wind resource study

2. San Francisco building-integrated wind power

3. Rooftop wind turbine demonstration site

4. California wind maps web tool

! Concluding Remarks

! DOE Built-Environment Wind Turbine RD&D Roadmap

Source: Mayda

UC Davis Energy Institute

! Established Fall 2007 as home to major UC Davis energy

research centers and education programs

! Campus-wide & administered through Office of Research

with multi-college support

! Created to focus and bring together campus strengths in

energy research, education, and outreach, and to build new

interdisciplinary programs and capabilities

! Strategic planning for effective energy transformation

! Approximately 150 faculty members across campus

California

Renewable

Energy

Collaborative

California Wind Energy CollaborativeMission Statement:

Support the development of safe,reliable, environmentally sound, andaffordable wind electric generationcapacity within the state of Californiaby managing a focused, statewideprogram of scientific research,technology development &deployment, and technical training. CALIFORNIA

WIND ENERGY

COLLABORATIVE

California

Energy

Commission

Federal, state, and

local government

agencies

Academia

Industry

Public

programs

Government and

industry research

labs

Education

&

Outreach

Engineering

Research

Inter-agency,

Inter-sector

Coordination

! A partnership of the California

Energy Commission and the

University of California

! Established in March 2002

! http://cwec.ucdavis.edu/

! info@cwec.ucdavis.edu

CWEC Research Focus

! Recent projects:

" Conversion Technology

! Blunt trailing edge airfoils (DOE, SNL)

! Rotor analysis (DOE, SNL, TPI,Clipper)

! Rotor passive load control, STAR(DOE, SNL, K&C)

! Rotor active load control (SNL)

! Load limiting algorithm (CEC/EISG,NREL)

" Development

! Wake effects (CEC)

! Forecasting (CEC, EPRI)

! Turbine setback (CEC)

" Grid Integration

! IAP (CEC)

! Ramping, variability of windplants(SMUD)

! Value of wind forecasting (CAISO)

" Operation! Anemometer calibration (CEC, Otech)

! Performance analysis of windplants(SMUD)

CALIFORNIA WIND ENERGY COLLABORATIVE

Coordination Research Training

Blades and Rotors

!Computational design and analysis

!Wind tunnel analysis

!Active and passive load control

!Development of improvements to blade

design and analysis methods

!Design and analysis of alternative

configurations

Emerging Technologies

!Offshore

!Evaluation of emerging technologies

Conversion Technology

!Application of forecasting to day-ahead

and hour-ahead energy markets

!Forecasting of power generation ramps

!Impact of distributed generation on

distribution networks

!Support future integration studies

!Applications and impacts of energy

storage

Grid Integration

Asset Management/Optimization for

Reliability

!Performance analysis and health

monitoring

!Condition monitoring

!Forecasting for maintenance scheduling

and plant/turbine operations

Anemometer Calibration

!Expand wind tunnel calibration

capabilities

!Anemometer sensitivity to complex,

real-world flows: inclined flows,

turbulence, effects of nacelle and

mounting fixtures

Operation

Resource Assessment

!Wind turbine wake effects

!Complex terrain

!Shear / wind patterns at tall heights

!Offshore

!Long range forecasting

!Improve accuracy of wind assessment

in small wind applications

!Wind assessment in urban

environments

Permitting

!Research to support the development

of safe, fair permitting criteria

Development

7

Atmospheric Boundary Layer Wind Tunnel

at UC Davis

! Tunnel specs

! Open-return type

! Overall length = 21.3 m

! Test section = 2.44m x 1.66m x 1.18m

! Typical model scale = 1:600

8

! AIR QUALITY & PLUME DISPERSION

" LLNL, LLBL & Industrial Safety Studies

" Sports Stadium Analyses (Pac Bell, etc.)

! LARGE SCALE ENVIRONMENTALSTUDIES

" Owens (dry) Lake Mitigation Studies

" Martian Dust Storm Analysis (NASA)

! PEDESTRIAN LEVEL WIND STUDIES

" San Francisco, Oakland & L.A. Studies

" Getty Museum Wind Analysis

! WIND ENERGY APPLICATIONS

" Altamont Wind Farm Forecasting Studies

" Turbine Siting in Complex Terrains

" Urban Wind Energy Studies

Source: Mayda

Environmental Fluid Dynamics Lab at UC Davis

9

! Objectives:

" Gain further understanding of wind resource in urban

environments (San Francisco)

! Testing Scheme:

" Pick sites for study

! Taller than surrounding buildings, conventional shape

" Perform wind tunnel tests

! 3-4 predominant wind directions per site

! Take measurements on building for each wind direction

" Obtain full scale winds from wind-tunnel data

" Estimate energy production for various turbines

! Integrate data with turbine power curves

Physical Modeling of San Francisco Wind

Power Resources (1)1

Project

10

! Approach:

" Use ABLWT to simulate

wind flow over cityscapes,

San Francisco, and complex

terrain

" Measures mean wind

speeds and turbulence

intensities near surfaces

" Measurements performed

for each wind direction of

significance

Source: Mayda

Physical Modeling of San Francisco Wind

Power Resources (2)1

Project

11

! Wind Data:

" Anemometer data from old Federal

Building

! H = 40.2m (132 ft) above ground

" Data from 1945 – 1947

! Used because of completeness and

representative of typical San Francisco

wind conditions (White, 2006)

" Average wind speed was 5 m/s (11 mph)

Source: Mayda

Physical Modeling of San Francisco Wind

Power Resources (3)

! Fluid parameters taken into consideration when modeling flow in

wind tunnel (see Appendix)

! Free-stream wind speed in wind tunnel = 3.8 m/s

" Data collected from wind tunnel experiments

! Wind speed ratio (R-value)

! Turbulence intensity value

1

Project

12

! Test Sites:

" 3 existing (The Fox Plaza, Bank

of America, CSAA buildings)

" 2 potential future developments

Source: Mayda

Physical Modeling of San Francisco Wind

Power Resources (4)

Courtesy Environmental Science Associates, 2006

! Measurement Locations:

" Numerous points tested

" Building faces, corners, rooftop

perimeter & profiles at specific

locations above the roof.

1

Project

**Manwell, J. F., J. G. McGowan, A. L. Rogers. Wind Energy Explained: Theory, Design and Application. San Francisco: John Wiley & Sons Ltd, 2003.

An example of annual average wind power densities in graphical form for each point is shown

above. The building’s points are shown in four views above. Similarly-styled results were obtained

for all buildings in this study.

Sample of Results – Fox Plaza

• “poor” (white dots): Pannual average/area: less than 100 W/m2

• “good” (green dots): Pannual average/area: between 100-700 W/m2

• “great” (yellow dots): Pannual average/area: greater than 700 W/m2

! Wind-tunnel data used to predict annual average wind power

densities for each measurement location on each building:

1

Project

14

! Wind tunnel tests showed the best place for a turbine is on

or above the roof level.

! However, also showed that each building had its own

specific set of wind characteristics.

" Therefore, testing on a specific site might be necessary

before installing a turbine.

! Conduct more wind tunnel tests:

" If more buildings are tested, might be possible to generalize

wind characteristics of certain types of cityscapes.

! Analyze impact of turbulence levels on turbines

! Compare wind tunnel tests with field anemometers

Source: Mayda

Project Outcomes

Recommendations

1

Project

15

Building Integrated Wind Energy Project2

Project

Full-scale 1:150 scale wind tunnel model

16

Building Integrated Wind Energy Project2

Project

Full-scale 1:150 scale wind tunnel model

17

Building Integrated Wind Energy Project2

Project

18

Building Integrated Wind Energy Project

Wind Tower Detail2

Project

19

! Bergey XL1 on roof of Bainer Hall

! Used as a demonstration site…

" Collecting meteorological data and

performance data

" Undergraduate senior design research

projects (redesign blade set)

" Basis for providing general wind energy

information (group tours, interested

students)

Small Turbine Demonstration Site at UC

Davis3

Project

Roof-Mounted Turbine Power Curve 3

Project

21

! Effort funded by California Energy Commission

! Develop an online wind assessment tool for general public" CEC/PIER funded development of detailed wind maps for California

! Maps provide annual wind power and speed at several heights above theground

! Maps generated by AWS TruePower

! Maps are available in pdf format from CEC website

! Difficult to pinpoint locations and determine wind speed at specified locationand height

! CEC has GIS-based version of wind maps

! Disadvantage of GIS-based wind maps is that specific software(ArcExplorer) is needed to access information

" Develop a web-based version of GIS-based wind maps

! Combine GIS-based wind maps with Google maps

! Allow users to click on or search for a particular location to view wind datainformation

! Able to get wind data as function of height

Source: Mayda

GIS Map Tool Interface 4

Project

! Maps of annual averagewind speed and power havebeen produced for California

! Maps have a grid resolutionof 200 m

! Actual winds at a specific sitefor the turbine can varysignificantly from the map

! Maps are good tools forguiding and estimating butdo not replace Micro-siting

Wind energy density at 50 meters above ground.

California Energy Commission.

http://www.energy.ca.gov/maps/wind.html

4

Project

California Wind Maps

23

Source: Mayda

GIS Map Tool Interface 4

Project

Concluding Remarks! San Francisco is an excellent location to

study wind in the built environment:

" Good wind resource

" Strong support by City

" High electricity rates

" Availability of net metering and CA rebateprograms

" Prominently mentioned in DOE built-environment wind turbine RD&D roadmap

! Effort should include:

" Develop detailed wind map for City

! CFD

! Anemometer measurements

! Wind tunnel

" Benchmark wind turbine test sites

" Web-based data & info site

! Effort should involve:

" Government (SF, CEC, DOE, et al.)

" Industry

" Academia

Danielle Murray

DOE Built-Environment Wind Turbine RD&D Roadmap

! Purpose of roadmap to provide a framework for achieving visionset forth by attendees of Built-Environment Wind TurbineWorkshop (Aug 2010, NWTC/NREL)

! Workshop vision statement:

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