renewable energy utilization · 2017-01-13 · energy systems research laboratory, fiu renewable...

Energy Systems Research Laboratory, FIU

Renewable Energy Utilization

Professor Osama A. MohammedDepartment of Electrical and Computer Engineering

EEL5285 & EEL 4930All Sections (Spring 2017)

Professor O. A. Mohammed, EEL5285 Lecture Notes, Spring 2017


What is CoveredPart I: Renewable Energy Systems• Introduction• Electric Systems in Energy Context• Basic Review of Electric Quantifies and Impact of Power Conditioning• Energy Efficiency and operational issues• Energy Generation and operation and control• Alternate and Renewable Energy Sources and its Economics

– Alternate and Renewable Energy Sourceso Wind Energyo Distributed generation technologieso Hydro Power o Wave/ Tidal Powero Cooling and Heat Pumpso The Solar Resource

Part II: Renewable Energy Utilization• Renewable Energy Utilization• Energy Storage including Electric/Pluggable Hybrid Cars• Smart Grid Integration Issues



Introduction: Notation - Power• Power: Instantaneous consumption of energy• Power Units

Watts = voltage x current for dc (W)kW – 1 x 103 WattMW – 1 x 106 WattGW – 1 x 109 Watt

• Installed U.S. generation capacity is about 900 GW ( about 3 kW per person)



Introduction: Notation - Energy• Energy: Integration of power over time; energy is what people

really want from a power system• Energy Units

– Joule = 1 Watt-second (J)– kWh = Kilowatthour (3.6 x 106 J)– Btu = 1055 J; 1 MBtu=0.292 MWh; 1MWh=3.4MBtu– One gallon of gas has about 0.125 MBtu (36.5 kWh); one

gallon ethanol as about 0.084 Mbtu (2/3 that of gas)• U.S. electric energy consumption is about 3600 billion kWh

(about 13,333 kWh per person)



North America Interconnections


Energy Systems Research Laboratory, FIUProfessor O. A. Mohammed, EEL5285 Lecture Notes, Spring 2017

National Transmission Map


Some Regional Transmission Systems



ERCOT -Electric Reliability Council of Texas FRCC -Florida Reliability Coordinating Council MRO -Midwest Reliability Organization NPCC -Northeast Power Coordinating Council RFC –Reliability First Corporation SERC –Southeastern Electric Reliability Corporation SPP -Southwest Power Pool WECC -Western Electricity Coordinating Council

Electric Grid Reliability Regions


Electric Systems in Energy Context• Focuses here is on renewable electric systems, but we first

need to put them in the context of the total energy delivery system

• Electricity is used primarily as a means for energy transportation

• Use other sources of energy to create it, and it is usually converted into another form of energy when used

• About 40% of US energy is transported in electric form, a percentage that is gradually increasing

• Concerns about need to reduce CO2 emissions and fossil fuel depletion are becoming main drivers for change in world energy infrastructure



World Energy Consumption

• worldwide energy demand is increasing rapidly (30% increase by 2030)

• World consumption is expected to increase by 36%, most of that growth is from China.



World Oil Prices are Going Down Since 2009

• Continued demand growth should drive oil prices higher, from IEA World Energy Outlook


The 450 Scenario assumes:• Different groups of

countries adopt binding economy-wide emissions targets in successive steps.

• This should reflect their different stages of economic development and their respective responsibility for past emissions.


USA Natural Gas Supplies

• EIA projections of USA natural gas supplies• expanding supplies of USA natural gas prices keep energy prices

down


Energy Information Administration (EIA) Projections


USA Electricity Production by Fuel

• EIA projections of USA electricity production by fuel

• The projected fuel mix for electricity generation gradually shifts to lower Carbon options


Expected to Increase

Significantly


USA Energy usage

• the U.S. consumes about 30% of all energy produced in the world

• usage has steadily increased, except during oil crises/major Recessions

• we have about 3% of the world's petroleum reserves, and consume about 25% of the world's petroleum production.



World distribution of energy resources• petroleum (oil) is

highly concentrated in the Middle East

• natural gas is concentrated in the former Soviet Union and Middle East

• coal is relatively uniform world-wide



Worldwide Oil Distribution

• Worldwide Oil Distribution.

• Concentration of resources in the Middle East has a dramatic impact on world politics and finance.



Worldwide Natural Gas Distribution

• Distribution of natural gas reserves worldwide

• Concentration of resources in the former Soviet Union is important, but overseas export is difficult.



Worldwide Coal Distribution

• Distribution of coal reserves worldwide

• Since coal distribution is relatively uniform, coal the universal energy source.



Sources of Energy in the US

Source: EIA Energy Outlook 2009

Petroleum, 38.9

Coal, 22.6

Natural Gas, 24.1

Nuclear, 9.3

Hydro, 2.6

Biomass, 3 Other, 1.4

CO2 Emissions (millions of metric tons, and per quad measure)Petroleum: 2598, 64.0 Natural Gas: 1198, 53.0Coal: 2115, 92.3

About 86% Fossil Fuels

1 Quad = 293 billion kWh (actual)

1 Quad = 98 billion kWh (used, taking into account efficiency)



Electric Generation by Fuel/State

Source: 2006 EIA Data

EIA: Energy Information Administration



Energy Consumption in the World• The total world-wide energy consumption was 472

quad (2006), a growth of about 19% from 2000 values for example.

• A breakdown of this value by fuel source is 171.7 quad (36.3%) from petroleum, 127.5 (27.0%) from coal, 108.0 (22.9%) from natural gas, 29.7 (6.3%) from hydroelectric, 27.8 (5.9%) from nuclear, 4.7 (1.0%) other used as electric power, 2.8 (0.6%) other not used as electric power

• World-wide total is 86.2% fossil-fuel, and (currently) less than 1.0% in the focus area of this class



Historical and Projected US Energy Consumption

EnergyinQuad

Source: EIA Annual Energy Outlook, 2010This data says we will be 81% Fossil in 2035!!



The World: Top Energy Users (in Quad), 2006 Data

• USA – 99.9• China – 73.8• Russia – 30.4• Japan – 22.8• India – 17.7• Germany – 14.6• Canada – 14.0• France – 11.4• UK – 9.8• Brazil – 9.6

World total is 472; Average per 100 Million people is about 7.32. If world used US averagetotal consumption would be about 2148 quad!

Source: US DOE EIA


A quad is a unit of energy equal to 1015 (a short-scale quadrillion) BTU, or 1.055 ×1018 joules (1.055 exajoules or EJ) in SI units.


Per Capita Energy Consumption in MBtu in Some Countries per Year (2006 data)

• Iceland: 568.6 Norway: 410.8• Kuwait: 469.8 Canada: 427.2 • USA: 334.6 Australia: 276.9• Russia: 213.9 France: 180.7• Japan: 178.7 Germany: 177.5• UK: 161.7 S. Africa: 117.2• China: 56.2 Brazil: 51.2• Indonesia: 17.9 India: 15.9• Pakistan: 14.2 Nigeria: 7.8• Malawi: 1.9 Afghanistan: 0.6

Source http://www.eia.doe.gov/pub/international/iealf/tablee1c.xls



Global Warming: What is Known is CO2 in Air is Rising

Source: http://www.esrl.noaa.gov/gmd/ccgg/trends/

• Value was about 280 ppm in 1800, 389 in 2010

• Rate of increase is about 2 ppm per year



The Worldwide Air Temperature is Rising (at Least Over the Last 150 Years)

Source: http://www.cru.uea.ac.uk/cru/info/warming/

Baseline is 1961 to 1990 mean



Monthly Worldwide Temp. Data, Last 40 Years (Celsius, 1961-1990 Deviation)

http://hadobs.metoffice.com/hadcrut3/diagnostics/global/nh+sh/monthly



Monthly Worldwide Temp. Data, Last 40 Years (Celsius, 1961-1990 Deviation)


U.S Annual Average Temperature

Source: http://www.noaanews.noaa.gov/stories2009/images/1208natltemp.png



Eventual Atmospheric CO2 Stabilization Level Depends Upon CO2 Emissions

Regardless of what we doin the short-term the CO2 levels in the atmosphere will continue to increase.

The eventual stabilizationlevels depend upon how quickly CO2 emissions are curtailed.

Emissions from electricity production are currently about 40% of the total



And Where Might Temps Go?

http://commons.wikimedia.org/wiki/File:Global_Warming_Predictions.png

Note that the modelsshow rate of increase valuesof between0.2 to 0.5 C per decade.The rate from1975 to 2005was about 0.2 C per decade.



World Population Trends Country 2005 2015 2025 %Japan 127.5 124.7 117.8 -7.6Germany 82.4 81.9 80.6 -2.2Russia 142.8 136.0 128.1 -10.3USA 295.7 325.5 357.4 20.8China 1306 1361 1394 6.7India 1094 1251 1396 27.6World 6449 7230 7941 23.1Source: www.census.gov/ipc/www/idb/summaries.html; values in

millions; percent change from 2005 to 2025



Energy Economics• Electric generating technologies involve a tradeoff

between fixed costs (costs to build them) and operating costs

• Nuclear and solar high fixed costs, but low operating costs

• Natural gas/oil have low fixed costs but high operating costs (dependent upon fuel prices)

• Coal, wind, hydro are in between• Also the units capacity factor is important to

determining ultimate cost of electricity• Potential carbon “tax” major uncertainty



Ball park Energy Costs

Source: http://www.oe.energy.gov/DocumentsandMedia/adequacy_report_01-09-09.pdf



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Natural Gas Futures Contract 1 (Dollars per Million Btu)

Natural Gas Prices Since 1994


Natural Gas Prices 1990’s to 2010

Marginal cost for natural gas fired electricity price in $/MWh is about 7-10 times gas price



Coal Prices have Fallen Substantially Recently

Source: http://www.eia.doe.gov/cneaf/coal/page/coalnews/coalmar.html#spot

Prices are on the order of $1 to $2 per Mbtu



Current Average weekly coal commodity spot prices in different US Regions (dollars per short ton ) [1 short ton= 0.907184 metic ton]

Week ending Week ago12/18/15 12/25/15 12/28/15 12/31/15 01/08/16 change

Central Appalachia12,500 Btu, 1.2 SO2 $43.50 NA $43.50 $43.50 $42.25 $-1.25

Northern Appalachia13,000 Btu, < 3.0 SO2 $48.95 NA $48.95 $48.95 $48.60 $-0.35

Illinois Basin11,800 Btu, 5.0 SO2 $32.60 NA $32.60 $32.60 $32.20 $-0.40

Powder River Basin8,800 Btu, 0.8 SO2 $10.90 NA $10.90 $10.90 $9.70 $-1.20

Uinta Basin11,700 Btu, 0.8 SO2 $40.65 NA $40.65 $40.65 $39.05 $-1.60

Source: With permission, SNL Energy

Energy Systems Research Laboratory, FIU Professor O. A. Mohammed, EEL5285 Lecture Notes, Spring 2017

Average weekly coal commodity spot prices dollars per MbtuWeek ending Week ago

12/18/15 12/25/15 12/28/15 12/31/15 01/08/16 change

Central Appalachia12,500 Btu, 1.2 SO2 $1.74 NA $1.74 $1.74 $1.69 $-0.05

Northern Appalachia13,000 Btu, < 3.0 SO2 $1.88 NA $1.88 $1.88 $1.87 $-0.01

Illinois Basin11,800 Btu, 5.0 SO2 $1.38 NA $1.38 $1.38 $1.36 $-0.02

Powder River Basin8,800 Btu, 0.8 SO2 $0.62 NA $0.62 $0.62 $0.55 $-0.07

Uinta Basin11,700 Btu, 0.8 SO2 $1.74 NA $1.74 $1.74 $1.67 $-0.07

Source: With permission, SNL Energy


Support for Renewable Energy

• The White House issued report about how the stimulus is going. Renewable energy projects were very much included. For example the largest solar PV installation in US, 579 MW Solo Star Site in California.

• Cost of residential solar is projected to decrease from $0.21 per kWh in 2009 to $0.10 in 2015 and $0.06 by 2030; wholesale parity is $0.05.

http://www.whitehouse.gov/sites/default/files/uploads/Recovery_Act_Innovation.pdf


Energy Systems Research Laboratory, FIU Professor O. A. Mohammed, EEL5285 Lecture Notes, Spring 2017

Solar Star (I and II) United States 34°49′50″N

118°23′53″W579 2015

Topaz Solar Farm United States 35°23′N 120°4′W 550 2014

Desert Sunlight Solar Farm

United States 33°49′33″N

115°24′08″W550 2015

Copper Mountain Solar Facility United States 35°47′N

114°59′W458 2015

Largest Solar Plants in the US


Wind is the Major Electric Renewable Growth Area Right Now

Source: EIA Energy Consumption by Energy Source, July 2009

2009 Data:Total: 94.5Coal: 19.7NG: 23.3Petro: 35.3Nuc.: 8.35Bio: 3.88Geo: 0.36Hydro: 2.68Wind: 0.70Solar: 0.11



Growth in US Wind Power Capacity

Source: AWEA Wind Power Outlook 2nd Qtr, 2010

The quickdevelopmenttime for windof 6 monthsto a year means thatchanges infederal tax incentivescan have an almostimmediateimpact onconstruction

AMERICAN WIND ENERGY ASSOCIATION - www.awea.org



Basic Review--Phase Angles• Angles need to be measured with respect to a

reference - depends on where we define t=0 • When comparing signals, we define t=0 once

and measure every other signal with respect to that reference

• Choice of reference is arbitrary – the relativephase shift is what matters

• Relative phase shift between signals is independent of where we define t=0



Example: Phase Angle Reference• Pick the bottom wave as the reference

1 sin4

v V t

2 sin 0v V t

1 sin 0v V t

2 sin4

v V t

1 2 4

1 2 4

• Or pick the top as the reference- it does not matter!



Important Properties: RMS

• RMS = root of the mean of the square• RMS for a periodic waveform

• RMS for a sinusoid (derive this for homework)

21 ( )o

o

t T

RMSt

V v tT

let ( ) cos( )pv t V t

2p

RMSV

V

T period



Important Properties: Instantaneous Power

• Instantaneous power into a load

p(t)= ( ) ( )v t i t( )v t

+

-

( )i t

( )= cos( )

( )= cos( )p V

p I

v t V t

i t I t

( )= ( ) ( )p t v t i t

( )= cos cos 22p p

V I V IV I

p t t

“Passive sign convention” –current and power INTO load

1cos cos cos cos2

Identity



Important Properties: Average Power

• Average power is found from

• Find the average power into the load (derive this for homework)

( )= cos cos 22p p

V I V IV I

p t t

1 ( )o

o

t T

tP p t dt

T

T period

P= cos2p p

V IV I

P= cosRMS RMS V IV I or



Important Properties: Real Power

• P is called the Real Power

• cos(θV-θI) is called the Power Factor (pf)

• We’ll review phasors and then come back to these defintions…

P= cosRMS RMS V IV I

P= Re{VI*}



Why Do We Use Phasors?• Simplifies calculations

- Turns derivatives and integrals into algebraic equations

- Makes it easier to solve AC circuits

d A j Adt

R( )R i (t)= Rv t

R

L( )L (t)= Ldi tv L

dt

C( )C (t)= Cdv ti C

dt

=V RI

=Lj IV V j LI

I=Cj V 1VI j C

LjX j L

1cjX j

C



Complex PowerVV= RMSV

II= RMSI

Asterisk denotes complex conjugate

*

*

VI

VI cos sinRMS RMS V I

RMS RMS V I RMS RMS V I

V I

V I jV I

SApparentpower

PReal Power

QReactive Power

S = P+jQ

SQ

P

(θV-θI)

Power triangle



Apparent, Real, Reactive Power

• P = real power (W, kW, MW)• Q = reactive power (VAr, kVAr, MVAr)• S = apparent power (VA, kVA, MVA)• Power factor angle• Power factor

*

*

*

VI

VI

VI cos sinRMS RMS V I

RMS RMS V I RMS RMS V I

S P jQ

V I

V I jV I

V I cos( )pf



Distribution System Capacitors for Power Factor Correction



Reactive Power Compensation

• Reactive compensation is used extensively by utilities• Capacitors are used to correct the power factor• This allows reactive power to be supplied locally• Supplying reactive power locally leads to decreased

line current, which results in– Decrease line losses– Ability to use smaller wires– Less voltage drop across the line



Balanced 3 Phase () Systems• A balanced 3 phase () system has

• three voltage sources with equal magnitude, but with an angle shift of 120

• equal loads on each phase• equal impedance on the lines connecting the

generators to the loads • Bulk power systems are almost exclusively 3• Single phase is used primarily only in low voltage,

low power settings, such as residential and some commercial



Advantages of 3 Power

• Can transmit more power for same amount of wire (twice as much as single phase)

• Torque produced by 3 machines is constrained

• Three phase machines use less material for same power rating

• Three phase machines start more easily than single phase machines



Three Phase Transmission Lines



Three Phase - Wye Connection• There are two ways to connect 3 systems

• Wye (Y)• Delta ()

an

bn

cn

Wye Connection VoltagesVVV

VVV



Wye Connection Line Voltages

Van

Vcn

Vbn

VabVca

Vbc

-Vbn

(1 1 120

3 30

3 90

3 150

ab an bn

bc

ca

V V V V

V

V V

V V

Line to linevoltages arealso balanced

(α = 0 in this case)



Delta Connection

IcaIc

IabIbc

Ia

Ib

a

b

*3

For the Delta phase voltages equalline voltages

For currentsI

3II

3

ab ca

ab

bc ab

c ca bc

Phase Phase

I I

II II I

S V I



Delta-Wye Transformation

Y

phase

To simplify analysis of balanced 3 systems:1) Δ-connected loads can be replaced by

1Y-connected loads with Z3

2) Δ-connected sources can be replaced byY-connected sources with V

3 30Line

Z

V



Per Phase Analysis

• Per phase analysis allows analysis of balanced 3 systems with the same effort as for a single phase system

• Balanced 3 Theorem: For a balanced 3system with• All loads and sources Y connected• No mutual Inductance between phases



Transformers Overview• Power systems are characterized by many different

voltage levels, ranging from 765 kV down to 240/120 volts.

• Transformers are used to transfer power between different voltage levels.

• The ability to inexpensively change voltage levels is a key advantage of ac systems over dc systems.

• In this section, we’ll development models for the transformer and will later discuss various ways of connecting three-phase transformers.



Distribution Transformer

115 – 35 kV distribution transformer

Radiators W/FansLTC



Transmission Level Transformer230 kV surge arrestors

115 kV surge arrestors

Oil Cooler

Radiators W/FansOil pump



Large Power Transformer



Residential Distribution Transformers

Single phase transformers are commonly used in residential distribution systems. Most distributionsystems are 4 wire, with a multi-grounded, commonneutral.



Power System Harmonics• So far we talked about fundamental frequency

analysis. Many traditional loads only consume power at the fundamental frequency. However, some loads, mostly electronic-based, tend to draw current in non-linear pulses, which gives rise to harmonics.– If current has half-wave-symmetry (values are

equal and opposite when separated by T/2) then there are no even harmonics



Quick Review of Fourier Analysis0

1 2 3

1 2 3

n0

n0

f(t) cos cos2 cos32

sin sin 2 sin32where 2 ,

2a ( )cos , 0,1,2,

2 ( )sin , 1,2,

T

T

a a t a t a t

b t b t b t

f T

f t n t dt nT

b f t n t dt nT

.



Switched-Mode Power Supply Current

Source: www.utterpower.com/commercial_grid.htm



Current Waveform with Harmonics

• Example- A diode bridge rectifier current waveform

• Top picture - DC & Fundamental only

• Middle picture- Up to 7th harmonic

• Bottom picture- Up to 15th harmonic

-15

-10

-5

0

5

10

15

50.1 50.12 50.14 50.16 50.18 50.2 50.22 50.24

-15

-10

-5

0

5

10

15

50.1 50.12 50.14 50.16 50.18 50.2 50.22 50.24

-15

-10

-5

0

5

10

15

50.1 50.12 50.14 50.16 50.18 50.2 50.22 50.24



Harmonic Current SpecturmThe below figure shows the harmonic current components for an 18-W, electronic-ballast compact fluorescent lamp.

Source: Fig 2.34 of “Renewable and Efficient Electric Power Systems” by Masters



Total Harmonic Distortion (THD)

22

1 2 3

2 2 2 2

( ) 2 cos cos2 cos3

But the square term is simplied by recognizing( ) ( 2 2 2and noting that the average value of the product of two sinusoids of d

rms avg avgI i I t I t I t

a b c a b c ab ac bc

22 22 2 231 21 2 3

2 2 22 3 4

1

iffering frequency is zero. This leaves

22 2 2

A common metric for distortion is total harmonic distortion (THD)

THD

rmsII II I I I

I I II



Efficiency and Home Energy Use• Whole-house energy efficiency approach –

find out which parts consume the most energy

http://www1.eere.energy.gov/consumer/tips/home_energy.html
