Going Green: The Growing Role of Permanent Magnets in

Going Green:

The Growing Role of

Permanent Magnets in

Renewable Energy Production

and Environmental Protection

Gareth P Hatch, Ph.D.

Director of Technology

Dexter Magnetic Technologies, Inc.

Presented at the Magnetics 2008 Conferenceheld in Denver, Colorado, USA, in May 2008

This paper was downloaded from Terra Magnetica, an independent online resource for information and commentary on magnetics & permanent magnets - covering materials, applications, technologies, sourcing issues, industry news and events.

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Gareth Hatch

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Going Green:The Growing Role of

Permanent Magnets inRenewable Energy Productionand Environmental Protection

Gareth P. Hatch, Ph.D.Director of Technology

Dexter Magnetic Technologies Inc.

http://www.dextermag.com

Magnetics 2008

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Outline

! Introduction! The Challenge of Global Energy Usage! Renewable Energy Resources & Devices

! Wind! Hydro! Ocean! Solar

! PM Devices for Environmental Protection! Future Challenges! Appendices

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Introduction

!Units of measurement: energy consumption!Metric tonne of oil equivalent (toe)!!Barrel of oil equivalent (boe)!!Based on average efficiencies of energy conversion!1 tonne oil " 6.8 bbl oil!1 toe " 42 GJ " 11.6 MW·h

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The Challenge of Global Energy Usage

Source: OECD / IEA [2007]

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Source: REN21 [2006]

Sources of Global Energy Supply

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!Power output of conventional power stations

2 – 10 GWHydro1 – 2 GWFuel oil1 – 2 GWCoal

1 – 1.5 GWNuclear0.5 – 1 GWNatural gas

Typical OutputEnergy Source

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!Global energy consumption will only increase!Projected growth of over 50% from 2005 to 2030!Projected AAGR of 1.6% between 2005 and 2030!From 6.5 billion people in 2005 to 8.1 billion by 2030

Sources: OECD / IEA [2006 & 2007] & United Nations [2006]

22.7 TW

17.1 Gtoe

2030

17.0 TW

12.8 Gtoe

2010

18.7 TW

14.1 Gtoe

2015

15.1 TWConsumption rate

11.4 GtoeGlobal energy consumption

2005Energy Source

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!Electricity demand will also accelerate!Recall that 1 toe ! 11.6 MW·h!Per OECD / IEA [2006]:

!Estimated 14.4 PW"h in 2004 – 16% of total consumption!Projected 28.1 PW·h in 2030 – 21% of total consumption

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Projected World Electricity Demand by Region

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!Obviously demand is not the only factor!Finite supply of fossil fuels!Geopolitics of energy [in]dependence!Connection between foreign & energy policies!Climate change considerations!Pollution control!Political mandates as economic drivers

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! “The energy future which we are creating is unsustainable. If we continue as before, the energy supply to meet the needs of the world economy over the next twenty-five years is too vulnerable to failure arising from under-investment, environmental catastrophe or sudden supply interruption”. --- OECD / IEA [2006]

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Renewable Energy Resources & Devices

!What is renewable energy ?!“Renewable energy is derived from natural processes

that are replenished constantly. In its various forms, it derives directly from the sun, or from heat generated deep within the earth”. --- OECD / IEA [2003]

!Electricity and heat generated from resources such as:!Wind!Hydro!Ocean [includes tidal – derived from Earth – Moon interaction]!Solar!Biomass!Geothermal

! Includes biofuels and hydrogen derived from renewable resources

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Wind

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!Wind energy!Currently most significant area for potential PM usage!Archer & Jacobson [2005]: 72 TW global potential

!Primarily land-based or near-shore stations!Resolve [2005]: 900 GW in US offshore wind potential

!Enough to replace all conventional power stations in the US

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Source: Archer & Jacobson [2005]

Mean annual wind speed in Europe, extrapolated to 80 m

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Source: Archer & Jacobson [2005]

Mean annual wind speed in North America, extrapolated to 80 m

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!Total installed wind power capacity in 2007

Source: Global Wind Energy Council [2008]

100.094.1TOTAL13.813.0Rest of World2.32.1Portugal2.52.4UK2.62.5France2.92.7Italy3.33.1Denmark6.46.1China8.58.0India

16.115.1Spain17.916.8US23.622.2Germany

% TotalPower [GW]

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!How does a wind turbine work?

Source: GE [2008]

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Source: Nordex [2008]

! Nordex N80 - generates 2.5 MW ! Rotor weight: 50 tonnes! Rotor diameter: 80 m! Rotor speed: 10-20 rpm! Tower height: 80 m! Rating: 3-25 m/s [5.6 – 56 mph]! Gearbox weight: 18.5 tonnes! Gearbox ratio: 1:68! Generator weight: 12 tonnes! Generator speed: 750-1300 rpm! Generator type: asynchronous double-fed [i.e. non-PM]

Conventional Large Wind Turbine

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!Wind energy!To what does 2.5 MW approximate?

!Power for 750 average single family US homes!Power for 1,250 average single family EU homes!Power for 5,000 average single family Chinese homes

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Source: EWEA [2007]

! e.g. REpower 5M – 5 MW! e.g. Enercon E126 – 7 MW! Power ! swept area of blades! Power ! cube of wind speed! Provides efficiencies of scale! Geared turbines reaching limit! Issues of weight & reliability! Next step: PM generators! Allows for smaller gearbox

Trend Towards Larger Turbines

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Source: Multibrid [2008]

! Multibrid M5000 - generates 5 MW ! Rotor weight: 76.6 tonnes! Rotor diameter: 116 m! Rotor speed: 6-15 rpm! Rating: 4-25 m/s [8.9 – 56 mph]! Total nacelle weight: 199 tonnes! Gearbox ratio: 1:10! Generator speed: 60-150 rpm! Generator type: synchronous PM

Geared Wind Turbine with PM Generator

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Source: Multibrid [2008]

Geared Wind Turbine with PM Generator

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!Wind energy!Final step: remove the gearbox altogether!!Results in direct drive turbine with PM generator

!Hub connected directly to generator shaft!Requires much larger diameter generator!Eliminates gearbox! Increased reliability! Increased mechanical efficiency

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Source: Scanwind [2008]

! Scanwind 3500 DL – generates 3.5 MW! Uses The Switch PMR3150 direct drive PM generator ! Rotor diameter: 91 m! Rotor speed: 10-20 rpm! No gearbox required! Capable of variable speed

Gearless Wind Turbine with PM Generator

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Source: The Switch [2008]

! Contains > 2,000 kg Nd-Fe-B!Br ! 1.2 T [12 kG]!Hcj ! 1.5 MA/m [19 kOe]

! Operating temp " 80 #C! Approx 0.6 kg / kW produced

The Switch PMR3150 PM Generator

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Source: The Switch [2008]

The Switch PMR3150 PM Generator

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Source: Treehugger.com [2006 & 2008]

! From MagLev Wind Turbine Tech! Claims ability to produce 1GW! Vertically aligned rotor! Magnetic levitated using PMs! Minimal friction losses! Scant information available!! 0.3 kW Chinese maglev turbines available

The Shape of Things to Come??

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Outline




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Hydro

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!Hydro!Largest “conventional” source of renewable energy!Potential 100 GW + in new construction

!e.g. Three Gorges Dam – 22.5 GW!Significant growth in small hydro [ < 10 MW ]

!Approximately 8-10% of total!Access to previously inaccessible sources!Common in “run-of-river” applications!Principal area of application for PM devices

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!Total installed hydro power capacity in 2006

Source: BP [2007]

100.0845TOTAL32.5275Rest of World2.118Sweden2.622Venezuela3.126Japan3.731India3.933Norway5.849Russia9.681US

11.597Brazil11.597Canada13.7116China

% TotalPower [GW]

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Source:Wikimedia Common [2007]

Cross-section of large hydro facility

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!Conventional large hydro turbines!Generally non-PM generators!Francis turbines

!most commonly used turbine for large hydro!90%+ efficiencies!Head range of tens to hundreds of meter

!Kaplan turbines!better suited for low head / high flow!Adjustable blades!Can achieve 90%+ efficiency

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Source: Voith-Siemens & Wikimedia Common [2007]

750 MW Francis turbine for hydro

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Source:Voith-Siemens [2007]

154 MW Kaplan turbine for large hydro

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Source: VA TECH Hydro [2005]

Bulb Turbine for Small Hydro

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Bulb Turbine with PM Generator

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! VA TECH Hydro ECOBulb – 1.02 MW ! Other units 0.5 – 5 MW! Single or double regulated axial design! Typical turbine speed: 150 rpm! Discharge: 15-100 m3/s! Head: 2-15 m! Direct coupled PM generator! Requires no gearbox! No external cooling required! Low profile – low impact


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! ECOBulb 4MW PM rotor ! Up to 97% efficient design! Uses “high energy” Nd-Fe-B! Other details “proprietary”! Other variations [e.g. rim mount]


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Ocean

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!Ocean energy!Estimated 7.5 PW potential in the oceans [OSU 2005]!Relatively low present capacity!Technology 15-20 years behind wind [OSU 2007]!Seawater 835 times more dense that air!Variety of methods of energy generation

!Wave motion!Tidal stream!Tidal barrage

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!Ocean energy!Wave motion

!Exploits both potential and kinetic energy!Estimated potential of up to 2 TW world wide [DoE 2007]!Less than 2 MW actually installed [OSU 2007]!Most powerful waves in 40! – 60! latitudes!Tend to be on western coasts!Peaks of 100 kW/m crest length

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Source: Centre for Renewable Energy Resources [2006]

Wave Power Levels in kW/m Crest Length

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Sources: UMIP, Finavera & Pelamis [2006-8]

Variety of Wave-Based Devices

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Source: Wave Dragon [2005]

! Wave Dragon – proposed 4MW! Water stored in reservoir ! Released via turbines! Total width: 260 m! Working wave range: 0.7 m +! Weight: 22,000 tonnes! 16 X 250 kW Kaplan turbines! Turbine speed: 125-250 rpm! Directly coupled PM generator

Overtopper Device with PM Generators

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Sources: Florida Tech [2005], Prado et al [2006] & AWS Ocean Energy [2007]

! Archimedes Wave Spring! Fixed to sea bed + floater! Pilot plant – 2 MW output! Floater: 9.5 m diameter! PM linear generator! Stroke length: 7m! Stroke speed: 2.2 m/s! Generator weight: 100 tonnes! 2008 installation - Orkney

Submerged Point Absorber with PM Linear Generator

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Source: NY Times, OSU & NSF [2007]

Floating Point Absorber PM Linear Generator Buoy

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Sources: OSU [2007]

! OSU SeaBeav 1 ! 1 kW prototype! Tested in 2007 off Oregon! Further tests underway! Uses Nd-Fe-B magnets

Floating Point Absorber PM Linear Generator Buoy

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!Ocean energy!Tidal stream

Source: GSFC / NASA [2002]

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Source: Marine Current Turbines [2008]

! MCT SeaGen – 1.2 MW! Installed Apr 2008 in N. Ireland! Secured to seabed! Total mass: 1,000 tonnes! Twin rotors: 16 m diameter! Rotors can be pitched 180!! Wings can be raised above sea level! Geared, non-PM generator

Geared Axial Flow Tidal Stream Turbine

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Source: OpenHydro [2007]

! OpenHydro Open-Centre Turbine! Test system - 250 kW! Installed at Orkney Jan 2007! No gearbox required! PM generator in outer rim! Uses venturi to increase speed! Will be scaled to MW range! Few other details available

Axial Flow Tidal Stream Turbine with PM Generator

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Source: WIPO / OpenHydro [2008]

Axial Flow Tidal Stream Turbine with PM Generator

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Outline




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Solar

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!Solar energy!Earth's surface receives 89 PW power from the Sun!Annual mean insolation varies across the globe

!Australian Outback: 5.9 kW·h/m2/day !Helsinki, Finland: 2.4 kW·h/m2/day

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[Values in kW·h/m2/day, normal to sun, on worst day of the year]

Source: EFuture [2007]

World Insolation Map

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!Total installed photovoltaic [PV] capacity in 2006

Source: IEA-PVPS [2007]

100.05.85TOTAL3.70.22Rest of World0.70.04South Korea0.70.04France0.90.05Italy0.90.05Netherlands1.20.07Australia1.20.07China2.10.12Spain

10.60.62US29.21.81Japan48.92.86Germany

% TotalPower [GW]

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!Total installed thermal solar capacity in 2006

Source: REN21 [2008]

100.0105.1TOTAL2.02.2Rest of World0.20.2South Africa1.11.2India1.21.3Australia1.71.8US2.12.2Brazil3.63.8Israel4.54.7Japan6.36.6Turkey

12.813.4EU64.567.7China

% TotalPower [GW]

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Source: Wikimedia Commons [2007]

! Air naturally heated in large greenhouse! Convection causes air to rise! Air escapes through tall tower! Passes through turbines! Connected to PM generators

Novel Concept: Solar Updraft Tower

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Source: Enviromission [2007]

! Prototype tested 1982-1989! Located in Manzanares, Spain! Tower height – 195 m! Tower diameter – 10 m! Greenhouse – 0.045 km2 [11 acres]! Generated 50 kW

Solar Updraft Tower

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Sources: Enviromission [2007] & T-Mation [2007]

! Larger versions now being proposed ! To be located in Spain or Australia! Tower height – 1,000 m! Low efficiency - 0.5%! Greenhouse – 38 km2 [9,390 acres]! Roof height – 10 -16 m! Air heated by 35 !C! Air flow of 15 m/s [34 mph]! Projected 200 MW via 32 turbines! Can use “greenhouse” as a greenhouse!! One proposal – PM turbine rim bearings

Solar Updraft Tower

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Source: T-Mation [2007]

Solar Updraft Tower

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PM Devices for Environmental Protection

!PM devices for environmental protection!Three examples of technologies enabled by PMs

!Reducing the environmental impact of drilling!Preventive maintenance of oil & gas pipelines!Emergency shut down of subsurface oil wells

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Source: National Petroleum Council [2007]

Reducing the Environmental Impact of Drilling

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Source: Mackenzie Gas Project [2007]

! a.k.a. “slant” drilling! Access where vertical drilling not possible! Grouping of up to 30-40 well heads! Increased exposed section length! Real-time data transmitted to surface! Direction of drill bit adjusted in 3D

Directional Drilling

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!Directional drilling!Real-time data transmitted back to surface

!Measurement while drilling [MWD]!Logging while drilling [LWD]

!Recent development – MRIL-WD!Magnetic resonance imaging – logging while drilling!MRI a.k.a. nuclear magnetic resonance imaging

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Source: Oilfield Review [2003]

PM-Based NMR Logging While Drilling

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Source: Oilfield Review [2003]

! Uses Sm-Co magnets! Exposed to 300 !F / 20 kpsi! Oriented parallel to tubular! Creates static polarizing field! High magnetic gradient! Unit inserted into drill string! Instrumentation also inserted

PM-based NMR Logging While Drilling

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!Preventive maintenance of oil & gas pipelines!Corrosion & mechanical defects are a major concern!Regular pipeline inspection required!Rapid, non-destructive method needed! Inspection tools known as “smart PIGs”!Magnetic flux leakage [MFL] used to detect anomalies

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Source: Kogas [2006]

! Pipeline completes circuit with tool! Defects cause anomalies! Sensors collect magnetic data! Positioning data also recorded! Some systems now use GPS

PM-based MFL Pipeline Inspection Tools

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Source: OnStream [2007]

! PM magnetizer module! Typically Nd-Fe-B magnets! Instrumentation modules! Sensors collect magnetic data! Positioning data also recorded! Some systems now use GPS

PM-based MFL Pipeline Inspection Tools

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!Emergency shut down of subsurface oil wells!Offshore deepwater oil wells becoming more critical!Surface-controlled subsurface safety valves [SCSSVs]!Potential “super” wells as deep as 40,000 feet!Highly corrosive, high pressure / high temp conditions

!Up to 400 !F, 30 kpsi!Presents challenges for conventional SCSSVs

! Internal wellbore pressure!Elastomeric seals

! Ideal solution isolates valve piston from the wellbore!Solution – PM linear coupler

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Source: Halliburton [2008]

! Halliburton Depthstar! Uses Sm-Co magnets! 100% metal-to-metal sealing! No moving seals within wellbore! Simplified hydraulics! Increase life of the well

SCSSSV Using PM Linear Coupler

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Future Challenges

!Key challenge: sustainable business models!What happens when the subsidies disappear?!True cost awareness of conventional sources required

!e.g. typical kW·h prices do not account for future CO2 mitigation!Smaller companies can tend to “re-invent the wheel”

!Particularly prevalent with wave energy concepts

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Future Challenges

!Key challenge: meeting the demand for Nd-Fe-B!New wind turbines will need tonnes of Nd-Fe-B!Also needed for emerging water-based devices!Potential competition with motors for electric vehicles!Major concerns over supply from China

!Significant threat - domestic Chinese consumption!Will new sources be online in time?

!Clear need for better ways to recycle Nd-Fe-B magnets!Some manufacturers now looking at superconductors

!Price of high temp superconducting materials dropping!Price of Nd-Fe-B rising!Concerns of further risk exposure via geopolitics

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Thank You!

For further information:

Gareth P. Hatch, Ph.D.Director of Technology

Dexter Magnetic Technologies, Inc.1050 Morse Avenue

Elk Grove Village, IL 60007USA

Tel: +1-847-956-1140Fax: +1-847-956-8205

Email: [email protected]: http://www.dextermag.com

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Appendix A: Units of Measurement

!A refresher on magnitudes

ISO prefix Order of magnitudekilo- (k) 103

mega- (M) 106

giga- (G) 109

tera- (T) 1012

peta-(P) 1015

exa- (E) 1018

zetta- (Z) 1021

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!Energy

Name Symbol Relationjoule J = 1.00 J

foot-pound ft·lb ! 1.36 JBritish thermal unit BTU ! 1.05 kJ

kilocalorie kcal ! 4.19 kJkilowatt-hour kW·h = 3.60 MJ

1 barrel oil equivalent boe ! 6.12 GJ1 tonne oil equivalent toe ! 41.85 GJ

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!Power

Name Symbol Relationwatt W = 1 J·s-1

megawatt-hour / year MW·h/yr ! 114.12 Whorsepower hp ! 745.70 W

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Appendix B: A Solar Thought Experiment

!Solar energy!How many PV cells needed for entire global demand?

!Current requirement of 15 TW!Sunniest regions receive mean insolation of 250 W/m2

!Assume solar cell efficiency of 10%!Results in total area of 600,000 km2

!Or, to put it another way...

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Appendix B: A Solar Thought Experiment

After Lewis [2002]. Image Source: Smalley [2004]

6 PV Cell Farms, each 200 miles x 200 miles!

Documents

Going Green: The Growing Role of Permanent Magnets in