The stationary energy sector & electricity industry technology© CEEM, 2006
2Stationary energy sector & electricity industry technology © CEEM 2006
Energy service delivery in the stationary energy sector
Primaryenergyformse.g:
coal, gas, nuclear,
renewable
energy losses & external impacts
generation transmission distribution
The electricity supply industryend-use
equipment delivering
energy serviceseg: light,
heat,motivepower
transmission distributiontreatment
The natural gas supply industry
Energy service companies focus on end-use options, eg:efficiency, CHP, solar
Equipment providers
3Stationary energy sector & electricity industry technology © CEEM 2006
Key issues for the electricity industryPart of the stationary energy sector:– In competition with other energy vectors to deliver
end-use energy servicesSignificant externalities:– Environmental (eg climate change)– Social (eg “essential good”)
Characteristics of electricity:– A high quality, secondary energy form:
Expensive to make but flexible to transport & use
– Specific physical properties
4Stationary energy sector & electricity industry technology © CEEM 2006
Specific properties of electrical energy:– No cost-effective storage of AC electricity– Instantaneous transmission & distribution– Flows according to network laws:
From all generators to all end-use equipment
Implications:– Supply & demand balance physically at all times:
Active demand-side participation important
– Electrical continuum - power station to end-useCannot assign energy from a particular power station to a particular end-use:
– ‘pool’ rather than ‘bilateral’ physical transactionsLarge and small industry participants not clearly separable
5Stationary energy sector & electricity industry technology © CEEM 2006
The electricity industry conversion chain
primaryenergyformse.g:
coal, gasrenewable
electricalenergyin thet&d
network
end-useenergyformse.g: light,heat,
motivepower
powerstations
end-useequipment
energy losses & external impacts
Electrical equipment providers
6Stationary energy sector & electricity industry technology © CEEM 2006
Coal-fired steam-cycle generator
660 MWAlternator
Electricity600 MW
1650 MWBoiler540oC,16 MPa
Ash: 50 t/hHeat: ~165 MWCO2: ~600 t/h
Coal250 t/h
Air2,500 t/h
660 MWTurbine
Steam1485 MW
825 MWlow-grade
heatSteam/water
cycle
>
800 MWlow-grade
heat
Cooling water70000 t/h
CondensorWater @ 30oC,
0.005 MPa
7Stationary energy sector & electricity industry technology © CEEM 2006
Gas turbine generator
Electricity
Generator
Air
Aircompressor
Exhaust gasesincluding CO2, NOX
Gasturbine
GasorOil
Combustor
Hotcompressed
gases
8Stationary energy sector & electricity industry technology © CEEM 2006
Combined cycle gas turbine (CCGT)
Generator
Electricity
Steam
Steamturbine
Heat recoveryboiler Hot gases including
CO2, NOX
Air
Aircompressor
Gasturbine
GasorOil
Combustor
Hotcompressed
gases
9Stationary energy sector & electricity industry technology © CEEM 2006
Energy flow in a CCGT (%)
GT100 %
30%
28%
Electricity58%
ST70 % 42 % Waste heat42%
10Stationary energy sector & electricity industry technology © CEEM 2006
Trends in key Combustion Turbine parameters (Cogeneration & On Site Power Production, Jan-Feb 2000)
Year 1967 1972 1979 1990 1998
Inlet Temp 0C 900 1000 1100 1250 1400
Comp Ratio 10.5 11 14 15 19-23
Exh Temp 0C 430 480 530 580 600
Max Rtg MW 60 80 100 250 280
Eff (OC) % 29 31 34 36 39
Eff (CC) % 43 46 49 53 58 54
46
100
GE LMS100
2005
11Stationary energy sector & electricity industry technology © CEEM 2006
Conversion efficiencies(from primary energy to electricity)
0
10
20
30
40
50
60
Blackcoal
Browncoal
OCGT CCGT
Efficiency %
12Stationary energy sector & electricity industry technology © CEEM 2006
Australia’s coal resources (www.industry.gov.au & SKM)
13Stationary energy sector & electricity industry technology © CEEM 2006
Australia’s natural gas resources& pipelines(www.ena.asn.au)
Reserves:• 90% in NorthwestAustralia
Linepack:• Hours in Victoria to days in other states
Trading arrangements:• Market in Victoria• Contract carriagein other states
14Stationary energy sector & electricity industry technology © CEEM 2006
Integrated coal gasification & combined cycle with carbon collection & storage(Simhauser, 2004)
15Stationary energy sector & electricity industry technology © CEEM 2006
Geosequestration options for CO2(Simhauser, 2004)
16Stationary energy sector & electricity industry technology © CEEM 2006
CCS does not mean zero emissionsIGCC with geosequestration will still have CO2 emissions– Energy-cost tradeoffs in CO2 capture from flue or gasifier stream;
also energy for transport and pumping underground
IEA (2001)
Coal IGCC with CO2 capture emits approx. 40% of standard CCGT (without capture)
17Stationary energy sector & electricity industry technology © CEEM 2006
Key findings of IPCC CCS report (www.ipcc.ch, 2005)
A portfolio of mitigation measures will be needed (CCS alone not sufficient)Large-scale CCS power plant don’t yet existBy 2050, 20-40% of fossil fuel CO2 technically suitable for CCS at cost of 13 to 67 A$/MWhDeployment needs CO2 price of 25-30 US$/MWhCCS might contribute 15-44% of cumulative mitigation effort to 2100, limited beyond that (identified storage sites would then be full)
18Stationary energy sector & electricity industry technology © CEEM 2006
Nuclear (fission) energyKey issues:• Power station safety• Nuclear waste storage • Terrorism & nuclear weapon proliferation
19Stationary energy sector & electricity industry technology © CEEM 2006
The civilian nuclear fuel cycle
Radioactivewastes
(Uranium Information Centre)
(COGEMA)
Uranium
20Stationary energy sector & electricity industry technology © CEEM 2006
Global possession of nuclear weapons(www.wikipedia.org)
Five NPT “nuclear weapon states”
Known to have nuclear weapons
Suspected to havenuclear weapons
Have had a nuclear weapon program
Could quickly build
nuclear weapons
21Stationary energy sector & electricity industry technology © CEEM 2006
Hydro energyFrom potential energy of water in storage damTo rotational kinetic energy in turbine and then electrical energyAt good sites, large hydro can be cheaper than coal-fired power stations
(www.greenhouse.gov.au)
Electrical power (kW):P ~ 10xFxHxE
Where:•F = water flow (metres3/sec)•H = gross head (metres)•E = efficiency (0.7-0.9)
22Stationary energy sector & electricity industry technology © CEEM 2006
Lake Eucumbene(3900 GWh/yr)
Snowy Mountains Scheme
Jindabyne pumps(240 GWh/yr)
Geehi
Tumut 1 & 2600 MW
Talbingo
Tumut 3Gen: 1500 MWPump: 600 MW Jounama
transfer tunnels
Murray 1 & 21500 MW
23Stationary energy sector & electricity industry technology © CEEM 2006
Tasmania’s power stations(Tas Govt 2000)
Derwent
GreatLake
Mersey
Gordon
King
Pieman
Woolnorthwind farm
65 (+75) MWMusselroewind farm (130 MW)
Bell Bay240MW
2500
1500
1000
750
500
Rainfall(mm)
www.hydro.com.au 24Stationary energy sector & electricity industry technology © CEEM 2006
Tidal energy
Low-head hydro with two-directional flowTidal range varies with solar-lunar alignmentSea water more corrosive than fresh waterLow head implies less cost-effective than most hydro
(www.greenhouse.gov.au)
25Stationary energy sector & electricity industry technology © CEEM 2006
Biomass energy
Energy crops, possibly also for salinity controlAgricultural by-products - eg bagasse (sugarcane)Municipal wastes (a difficult fuel due to diverse nature)Burn directly or convert to liquid or gaseous fuels
(www.greenhouse.gov.au)
26Stationary energy sector & electricity industry technology © CEEM 2006
Albany wind farm, Western Australia
27Stationary energy sector & electricity industry technology © CEEM 2006
(European Commission, 2005)28Stationary energy sector & electricity industry technology © CEEM 2006
Australian wind resource(Approximate estimates, with average speeds in m/s)
(www.greenhouse.gov.au)
29Stationary energy sector & electricity industry technology © CEEM 2006
Wave energyWave energy derives from wind energy:– Energy density varies
dramaticallyNeed strength to survive storms yet cheap & sensitive enough to produce energy from small wavesStill under development
(www.greenhouse.gov.au)
30Stationary energy sector & electricity industry technology © CEEM 2006
Emerging wave power technologies
31Stationary energy sector & electricity industry technology © CEEM 2006
Geothermal energy - radioactive rockAustralia has plentiful radioactive rock at ~3,000m covered by insulating layers:- safe nuclear energyTrial in Cooper Basin, SA
(www.greenhouse.gov.au)
32Stationary energy sector & electricity industry technology © CEEM 2006
Distributed resources (DR)Small generators or storage embedded in an electricity distribution network:– Cogeneration:
Useful heat (or cooling) as well as electricity
– Emerging technologies:Micro gas-turbines, fuel cells
– Renewables Biomass, small hydro, wind, photovoltaics
– Reversible storage:eg batteries, flywheels
Demand-side resources
33Stationary energy sector & electricity industry technology © CEEM 2006
A regional electricity network
Transmission(220-500 kV)
Sub-transmission(33-132 kV)
Distribution(11-33kV)
Reticulation(240/415 V)
Inter-connectorto another region
Transmissionsubstation
SmallConsumers
LargeGenerators
100-700 MVA
EmbeddedGenerators≤ ~30 MVA
LargeConsumers
Meshed transmission network Radial distributionnetwork
Zone substation
34Stationary energy sector & electricity industry technology © CEEM 2006
Potential benefits of cogeneration (CHP)compared to gas steam cycle (or CCGT)
100
FuelFuel
85 (57)
56
Separateproduction
Power stationefficiency
40% (60%)
Boilerefficiency
90%
34 units ofelectricity
&50 unitsof steamper hour
Industrialprocess
50
3434
50
Total141
(113)
Total100
CHP
Electricalefficiency
34%
Heatefficiency
50%
Benefit of CHP depends on balancebetween electricity & steam requirements
& efficiency of retail electricity & gas markets
35Stationary energy sector & electricity industry technology © CEEM 2006
Capstone Micro-turbine
• 30 kW• 400-480 V, 50-60 Hz• 25% efficiency whenfuelled by high pressurenatural gas (LHV)
• 500 kg• 1.9x0.7x1.3 metres• Became commerciallyavailable in 1999
36Stationary energy sector & electricity industry technology © CEEM 2006
PEM fuel cell (PEFC)(http://www.ballard.com, 2001)
Anode:-• Hydrogen disassociates into
protons & electrons at ~90oC• Electrons flow to cathode via
external circuit(~0.6 volts/cell DC)
Membrane:• Protons pass through to
cathodeCathode:• Returning electrons combine
with protons & oxygen to produce water vapour
250 kW prototype PEFC
37Stationary energy sector & electricity industry technology © CEEM 2006
Ballard residential fuel cell concept(http://www.ballard.com, March 2001)
1 kW PEFC Engineering Prototype Feb 2001:~40% elec efficiency & ~40% heat efficiency
38Stationary energy sector & electricity industry technology © CEEM 2006
Solar energy - photovoltaicsPV cells convert solar energy directly to DC electricity
– Use inverter to create ACStand-alone or building integrated
650 kW, Newington (Pacific Power)
200kW, Singleton (EnergyAustralia)
39Stationary energy sector & electricity industry technology © CEEM 2006
Solar thermal concentrators for electricity generation(www.greenpeace.org)
Parabolic trough (~350MWe):– Most mature but low efficiency
Central receiver (~10MWe):– High efficiency but pre-commercial
Parabolic dish (<1MWe):– High efficiency but pre-commercial
Tower (50MWe)– Artificial wind;
pre-commercial
40Stationary energy sector & electricity industry technology © CEEM 2006
Building Integrated PV & Solar Hot Water assessment:Key variables:– System efficiency– Solar radiation– Temperature– Rooftops
area,orientation, tilt, shading
Further work needed:– Rooftop resource– ShadingAustralia has excellent solar resources but best in NW
Solar Resource
(www.greenhouse.gov.au)
41Stationary energy sector & electricity industry technology © CEEM 2006
Australian Primary Energy Use 2000-01(ABARE, quoted in Energy & Resources Working Group, 2003; www.greenhouse.gov.au)
28%
13%
34%
20%
5%
Black coalBrown coalCrude oilNatural gasRenewables
42Stationary energy sector & electricity industry technology © CEEM 2006
Comparing electricity generation options(CO2 Coefficients & Costs: Securing Australia’s Energy Future (most); Energy payback: Wind:www.windpower.dk; PV: www.eere.energy.gov)
<1
<1
<1
2-5
<1 (unknown)
<1(unknown)
Egy Payback (yr)
3-11
9-21
6-29
100-280
450-660 (80-150)
700-1100 (150-200)
CO2 g/kWh
30-70Hydro
n/a (Aust.)Nuclear
50-80Wind
250-400Solar
35-45 (unknown)
Gas CC (CCS)
30-40 (unknown)
Coal SC (CCS)
Cost in 2010 ($/MWh)
Type
43Stationary energy sector & electricity industry technology © CEEM 2006
Inter-temporal linksEnergy-limited hydro:– Use water now or save till later?
Which strategy will give greater return?
Steam cycle thermal plant:– Start-up time can be many hours– Fuel stockpile management– Maintenance schedulingGas turbines:– Maintenance penalty if start/stop too often– Start-up time & fuel stockpile management
44Stationary energy sector & electricity industry technology © CEEM 2006
EnergyAustralia System - Summer 2000/01 Profiles - Peak and Average Days
0
1000
2000
3000
4000
5000
2:00 4:00 6:00 8:00 10:00 12:00 14:00 16:00 18:00 20:00 22:00
MW
23 Jan 2001
Avg Workday
Avg NonWorkday
Air conditioning usage
0
2000
4000
6000
8000
10000
12000
14000
Sunday Monday Tuesday Wednesday Thursday Friday Saturday
07 to 13 March 2004 27 to 02 August 2003NSW summer & winter peak demand
45Stationary energy sector & electricity industry technology © CEEM 2006
2003 Load duration curves for NEM states(NEMMCO SOO documents, 2004)
0
10
20
30
40
50
60
70
80
90
100
0 10 20 30 40 50 60 70 80 90Percentage of time
New South Wales Victoria Queensland South Australia Tasmania
46Stationary energy sector & electricity industry technology © CEEM 2006
Demand side resources
Any cost-effective action taken on the demand side of the electricity industry, e.g:– Reducing demand at times of supply constraint:
load shifting; curtailment of lower-value end-uses
– Improving end-use efficiency:e.g. compact fluorescent light globe
– Fuel switching at the point of end-use, eg:to natural gas or an end-use renewable such as solar water heating
47Stationary energy sector & electricity industry technology © CEEM 2006
Evidence of demand side response:NEM Victorian region, 8/2/01 (NECA, 2001)
48Stationary energy sector & electricity industry technology © CEEM 2006
Demand-side participation & projected low reserve conditions (NEMMCO SOO Executive Summary, 2004)
49Stationary energy sector & electricity industry technology © CEEM 2006
Deterministic method to compare resource investment options: “optimal resource mix”
Key attributes for comparison of generation or demand side resource options:– Investment lead time– Direct costs:
Investment cost (expressed as K $/kW/yr)Operation and maintenance (O&M) cost:
– Fixed: F $/kW/yr; Variable:- V $/kWh
– External impacts:Land, water, air, visual, noise
– Operating characteristics:Starting time, operating constraints, fuel availability
50Stationary energy sector & electricity industry technology © CEEM 2006
Annual cost of resource option ‘i’(assumed to be known with certainty & network costs or benefits ignored)
Direct cost can be expressed as:– Cost independent of output: (Ki + Fi) $/kW/yr– Cost that varies with output: Vi $/kWh
Total annual cost of operation (TC) is:TC = (Ki + Fi) + (Vi x CF x 8760) $/kW/yr
– Where annual capacity factor, CF is:
annual energy in kWh(rated kW)x8760
CF = Where 0≤CF≤1
51Stationary energy sector & electricity industry technology © CEEM 2006
‘Optimal’ resource mix (generation & demand)‘peak duty’ option
‘base duty’ option
‘intermediate duty’ option(voluntary)
demandreduction
envelope of cheapest available options
breakevenpoints
C1 C2 C3
$/kW/yr
Capacityfactor
1052Stationary energy sector & electricity industry technology © CEEM 2006
Capacityfactor0 1
MW
Load duration curve & resource mix(ideal case: no uncertainty in demand or unit availability & no load growth)
base duty resources
C3C2
intermediate duty resources
C1
peak duty resourcesdemand reduction
load duration curve
53Stationary energy sector & electricity industry technology © CEEM 2006
Summary
Large steam-cycle turbo-generators:– The “workhorse” of the electricity industry:
Coal, oil, gas or nuclear
– Combined cycle - a recent enhancement“Embedded” & renewable energy generation:– CHP, fuel cells, hydro, wind…– Demand-side options - neglected to date:
End-use efficiency, voluntary demand reduction
Procedure to track the “optimal mix”:Centralised (traditional) or decentralised (competitive)