Jun 28, 2013 - Amortized metrics such as EROI may disguise the costs of rapid scale-up or transition to alternative ener
Fueling the Energy Transition: The Net Energy Perspective
Michael Dale Global Energy Systems 2013 June 28th, Edinburgh
Outline: • What do we mean by ‘net energy’? • Why is net energy important? • Case study 1: energy balance of the PV industry • Case study 2: energy balance of wind industry • What about storage? • Implications 2
Disclaimer : • I’m a physicist, not an economist, I think of energy as a currency. • When I say: “cost”, “spend”, “buy”, “cheap”, “expensive” “surplus”, “deficit”, “subsidy”, “debt”, “profit”, “budget”, “invest” “afford” I am talking in terms of energy 3
Outline: • What do we mean by ‘net energy’? • Why is net energy important? • Case study 1: energy balance of the PV industry • Case study 2: energy balance of wind industry • What about storage? • Implications 4
What do we mean by ‘net energy’? • Definition: Net energy yield is “the amount of energy delivered into the mainstream of economic activity less the amount which is required to bring it there” (Peet, 1986)
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What do we mean by ‘net energy’? • Definition: Net energy yield is “the amount of energy delivered into the mainstream of economic activity less the amount which is required to bring it there” (Peet, 1986) Feedback Energy
Energy Sector
Gross Energy
Net Energy 6
What do we mean by ‘net energy’? • Definition: Net energy yield is “the amount of energy delivered into the mainstream of economic activity less the amount which is required to bring it there” (Peet, 1986) Feedback Energy
Energy Sector
Gross Energy
Net Energy
N.B. Gross Energy is what is measured by IEA, EIA, UN, BP, Shell, etc.
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Outputs
Gross Energy Production, Eg
Eg Eop
t (yrs)
tL
Inputs
Net Power [J/yr]
Energy flows for single power plant
Operation, Eop tc
Construction, Ec
Decommission, Ed 8
Net energy of power plant depends on two factors:
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Net energy of power plant depends on two factors:
• Energy inputs – How much energy is required to deploy and run each unit of power capacity Cumulative Energy Demand (CED)
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Net energy of power plant depends on two factors:
• Energy inputs – How much energy is required to deploy and run each unit of power capacity Cumulative Energy Demand (CED)
• Energy output – How much energy each unit of capacity produces Capacity factor
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Net energy of power plant depends on two factors:
• Energy inputs – How much energy is required to deploy and run each unit of power capacity Cumulative Energy Demand (CED)
• Energy output – How much energy each unit of capacity produces Typical values:
Capacity factor
Nuclear: 90% Coal: 80% Wind: 30% PV: 15%
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We can now define useful ‘net energy’ metrics
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We can now define useful ‘net energy’ metrics • Energy return ratios: How many times over will our energy investment pay back? e.g. energy-return-on-investment (EROI);
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We can now define useful ‘net energy’ metrics • Energy return ratios: How many times over will our energy investment pay back? e.g. energy-return-on-investment (EROI);
Typical values: Nuclear: 10-20 Coal: 10-30 Wind: 20-60 PV: 7-30
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We can now define useful ‘net energy’ metrics • Energy return ratios: How many times over will our energy investment pay back? e.g. energy-return-on-investment (EROI);
• Energy payback time (EPBT):
Typical values: Nuclear: 10-20 Coal: 10-30 Wind: 20-60 PV: 7-30
How quickly will our energy investment be paid back?
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We can now define useful ‘net energy’ metrics • Energy return ratios: How many times over will our energy investment pay back? e.g. energy-return-on-investment (EROI);
• Energy payback time (EPBT):
Typical values: Nuclear: 10-20 Coal: 10-30 Wind: 20-60 PV: 7-30
How quickly will our energy investment be paid back? Typical values: Nuclear: 3-5 yrs Coal: 2-5 yrs Wind:
