GENG4410

Fossil to Future: The Transition

Basic theory and Greenhouse Gasses

Dr. Bruce Norris Dr. Brendan Graham

Power

• Power is the rate of doing work or rate of energy

conversion
𝑃𝑜𝑤𝑒𝑟 = 𝐸𝑛𝑒𝑟𝑔𝑦 / 𝑇𝑖𝑚𝑒
𝐽
𝑃𝑜𝑤𝑒𝑟 = = 𝐽𝑠 −1
𝑠
• Power is expressed in Watts

1 𝑊𝑎𝑡𝑡 𝑊 = 1𝐽𝑠 −1 = 1𝑘𝑔. 𝑚2 . 𝑠 −3

Power Usage

• Power usage is usually in power x time notation

– kWh, MWh, GWh
• A kilo watt hour = 1000w x 3600s = 3,600,000J
• Why use kWh rather than joules
• Domestic electricity use is given in W
– 60W light bulb, 6kW air conditioner
– A 60W lightbulb on for 3 hrs = 0.18 kWh or 10,800J
– Electricity charged at 27c/kWh
– Light = 5c, air conditioner = $5 for 3 hrs usage
Alternate Units

• British Thermal Unit (BTU) = 1.05kJ

• Horsepower (hp) = 0.75kW = hp/h = 2.7MJ
• Barrel of oil equivalent (BOE) = 6.1GJ = 1.7MWh
• Standard Cubic Feet (nat gas) (SCF) = 1000BTU = 1.05MJ
• 1Tcf = 1 Quad
• 5800SCF = 1BOE
• calorie – energy – 4.18J
• Calorie – food – 4.18kJ (really kilo-calories)
Quick Calculation

• Given a Solar Panel produces 300W/m2

• How much land needs to be covered in panels to
meet world energy supply by Solar Power?
• What country is this equivalent to?

• 500,000,000,000 GJ = global amount of energy

humans consume per year
A Solution (not the solution)
𝑊 𝑠𝑢𝑛 2400𝑊ℎ𝑟 2
300 2 ⇒ 8ℎ𝑟 ⇒ ⇒ 2.4𝑘𝑊ℎ/𝑚
𝑚 𝑑𝑎𝑦 𝑚2

𝑘𝑊ℎ 876 𝑘𝑊ℎ

2.4 2 𝑥 365 𝑑𝑎𝑦𝑠 = 2
𝑚 𝑚 𝑦𝑒𝑎𝑟
500,000,000,000,000,000,000𝐽/𝑦𝑒𝑎𝑟
3600𝑠 𝑥 1000𝑊

= 138,888,888,888,889 kWh/year
𝑘𝑊ℎ
138,888,888,888,889 1,000,000𝑚2
𝑦𝑒𝑎𝑟
/( )
𝑘𝑊ℎ 𝑘𝑚 2
876
𝑚2 𝑦𝑒𝑎𝑟
= 158,550 𝑘𝑚2

An area of Bangladesh or Tunisia or about 2/3 of Victoria

Assumptions: 8 hrs a day of full capacity, 365/year

Reality, 250 days at 70% capacity, 2x area for access/shadows
= 661,380 𝑘𝑚2
An area of Afghanistan, ½ South Africa, Almost NSW,

Install cost: approx. $49 trillion dollars @ 50c/W

Maintenance cost approx. $3 trillion dollars/yr @ 18yr
lifespan
 What about Wind?

Wind turbines = 10,000,000 km2

USA or China or Canada under windfarms

Install Cost: approx. $80 trillion dollars to install @

$2mil/MW
Maintenance cost approx. $2 trillion dollars/yr @ 30 yr
lifespan

World energy demand increase @2.9%

Cover UK or NZ with wind farms every year upon year upon …..
Another $2 trillion dollars each year
Global Energy Investment
Energy Investment
Clean Energy Investment
Clean Energy Investment
China Energy Sources
Clean Energy Costs

Why the increase?

Clean Energy Costs
Clean Energy Scale Up
Global Electricity Investment
Viability of Green Energy
Constraints
Investment Pipeline
O&G Company Green Spending
Major Uses of Energy (Last Week)

• Electricity
Low Hanging Fruit
• Transport
• Thermal Heating
• Industry/Manufacturing/Chemical Production
Investment in Efficiency
 EV Car Manufacturers
ICE and EV
Battery Manufacturing
Grid Issues

https://grist.org/energy/renewables-are-growing-but-a-backlog-of-projects-is-holding-up-a-greener-grid/
Grid Issues

• Average delay for approval 4 years

• New connections require years of study before connection
– Grid balance, transmission limits etc
– A proposal pulling out required all other proposals to re-start
study from the beginning
• New transmission requires approval from all authorities it
crosses
• Average delay 5-7 years
– Some proposals still not full litigated from 2007
 Grid Connection Delays

Queued projects would meet 80% clean electricity in USA

https://www.energy.gov/sites/default/files/2022-04/Queued%20Up%E2%80%A6But%20in%20Need%20of%20Transmission.pdf
Combustion Reactions

• Hydrocarbons made up from Hydrogen and Carbon

• Alkanes 𝐶𝑛 𝐻2𝑛+2
• When combusted (burnt in oxygen) produce carbon
monoxide, carbon dioxide and water
• If sulphur present, combusts to SO2 (SOxs)
• If nitrogen present, combusts to NO2 (NOxs)
Combustion

• Complete combustion produces carbon dioxide and water

𝐶4 𝐻10 + 6.5𝑂2 4𝐶𝑂2 + 5𝐻2 𝑂
• Partial combustion produces carbon monoxide and water
𝐶4 𝐻10 + 4.5𝑂2 4𝐶𝑂 + 5𝐻2 𝑂

𝐶 + 𝑂2 ՜𝐶𝑂2 Δ𝐻𝐶° = −393.5 𝑘𝐽/𝑚𝑜𝑙

1
𝐻2 + 𝑂2 ՜𝐻2 𝑂 Δ𝐻𝐶° = −286 𝑘𝐽/𝑚𝑜𝑙
2
Heating Values, HHV and LHV

• How much theoretical energy you get out

combustion depends on what physical state you
measure the products and reactants.
• Generally measured with reactants and products at
25ºC
• When you combust a hydrocarbon you make water
vapour but do you measure the energy of water in
the vapour or the condensed liquid state?
Heating Values, HHV and LHV

𝐶4 𝐻10(𝑔) + 6.5𝑂2(𝑔) 4𝐶𝑂2(𝑔) + 5𝐻2 𝑂(𝑙)

• Higher Heating Value – liquid water = 2877 kJ/mole

𝐶4 𝐻10(𝑔) + 6.5𝑂2(𝑔) 4𝐶𝑂2(𝑔) + 5𝐻2 𝑂(𝑔)

• Lower Heating Value – water vapour = 2659 kJ/mole

• HHV products are returned to 25ºC and energy form
water condensation recovered
• LHV products are stopped at 150ºC and water remains a
vapour. The condensation energy is NOT recovered
HHV and LHV

• HHV (GCV – gross calorific value) is the same as

the heat of combustion when looking up standard
data. HHV is used when water vapour can be
condensed and heat below 150ºC can be recovered
(gas fired boiler)
• LHV (LCV - lower calorific value) is used when the
product gasses aren’t to be condensed, example
car engine. Heat below 150ºC cant be recovered.
 HHV and LHV

HC+O2

LHV
Energy

CO2(gas) + H2O(gas)

HHV
CO2(gas) + H2O(liquid)

Reaction Progress
Energy Generation Efficiency

• All methods of energy generation/conversion have

an efficiency associated with them
• Some techniques have a theoretical upper limit on
efficiency
– Thermal, wind, hydro
• Others currently have a technological limit
– solar
 Thermal Efficiency

• Measures performance of a device using thermal energy

– Internal combustion engine
– Steam engine
– Boiler
– Gas turbine
• Heat Engine
– absorbs heat energy from the high temperature heat source,
converting part of it to useful work and delivering the rest to
the cold temperature heat sink
Carnot Cycle

• Carnot engine is perfect engine giving maximum

efficiency
𝐸 𝑡𝑜𝑡 = 𝐸 𝑘𝑖𝑛 + 𝐸 𝑝𝑜𝑡 + 𝑈
𝐸 𝑡𝑜𝑡 = 𝐸 𝑘𝑖𝑛 + 𝐸 𝑝𝑜𝑡 + 𝑈
∆𝐸 𝑡𝑜𝑡 = ∆𝑈
𝑄 + 𝑊 = ∆𝑈

Q = Heat
W = Work
U = Internal Energy
Carnot Cycle

• For Carnot cycle 𝑄 + 𝑊 = ∆𝑈

∆𝑈 = 0 ⇒ 𝑄 = 𝑊 ⇒ 𝑊 = 𝑄𝑐 − (−𝑄ℎ )

−𝑊 𝑄𝑐
Real Efficiency 𝜂= =1−
−𝑄ℎ 𝑄ℎ

𝑇𝑐 Δ𝑆 𝑇𝑐
Max Efficiency 𝜂𝑚𝑎𝑥 =1− =1−
𝑇ℎ Δ𝑆 𝑇ℎ

T in absolute temperature
http://galileoandeinstein.physics.virginia.edu/more_stuff/flashlets/carnot.htm
 Carnot Cycle

Isentropic = no change in entropy during process (compression, expansions)

Practically = adiabatic and frictionless = no heat lost or transferred during process
 Thermal Efficiency

• Carnot Engines over-estimate efficiencies due to its

idealised nature
• Endo-reversible heat engines are closer to reality

𝑇𝑐
𝜂 =1− T in absolute temperature
𝑇ℎ

Power Station Tc(°C) Th(°C) η-Carnot η-Endo η-Observed

West Thurrock - Coal Fired 25 565 0.64 0.40 0.36
CANDU - Nuclear 25 300 0.48 0.25 0.30
Larderello - Geothermal 80 250 0.33 0.178 0.16
The Greenhouse Effect

• On of the major drivers for uptake of renewable and

clean energy
• It is the warming of the earth through heat being
trapped in the atmosphere
• Fossil fuel combustion and use are a major
contributor
Major Greenhouse Gases?
How does Greenhouse Effect Work

• The sun emits short wave radiation, UV and N-IR

• Average solar irradiance is 340 W/m2

• The earth emits longer wave IR radiation

Earth Energy Cycle
Earth Energy Cycle

• To keep stable temperatures the earth must get rid of

the 168 W/m2 (48%) that falls on the surface
• Energy leaves the surface through three mechanisms
– Evapouration
– Convection
– Thermal IR radiation
• The surface of the earth radiates 17% of incoming
energy
• The amount escaping directly to space is 12%
• 5-6% of irradiated energy is absorbed by
greenhouse gasses
Natural Greenhouse

• The atmosphere contains natural amounts of

greenhouse gasses
• Why doesn’t it heat up
• As the surface gets hotter it radiates more heat and
more energy leaves into space
𝑅𝑎𝑑𝑖𝑎𝑡𝑒𝑑 𝐻𝑒𝑎𝑡 ∼ 𝑇𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒 4
• If the Temperature doubled, the radiated heat would
increase by a factor of 16
• This stops the world continually heating up and an
equilibrium temperature is achieved
Greenhouse Gasses

• Water Vapour is major absorber but also has non-

absorbing windows allowing energy to escape
• Carbon Dioxide absorbs in these windows reducing
the energy leaving the atmosphere

Energy From Sun to Earth Energy From Earth to Space

Man Made Greenhouse Gasses

• Carbon Dioxide absorbs thermal infrared energy

radiated from the surface of the earth and stops it
leaving (approx. 0.8 W/m2)
• If we stop adding greenhouse gasses to the
atmosphere, the earth would achieve a new warmer
equilibrium temperature.
• As we keep adding more and more, the
temperature keeps rising
Global Warming Potential

Gas Formula Lifetime Global Warming Potential

(years) 20-yr 100-yr 500-yr
Carbon Dioxide1 CO2 30-95 1 1 1
Methane1,2 CH4 12 84 28 7.6
Nitrous Oxide2 N2O 121 264 265 153

1 Energy Sector
2 Agriculture Sector
 Balance of Effects Shows Warming
• Overall balance of
historical data shows
warming

1
Temperature Anomaly

0.8
0.6 AR6 WGI Report: The Physical Science Basis
0.4 (2021); Fig. 7.7
(°C)

0.2
0
-0.2
-0.4
-0.6
1880 1920 1960 2000
NASA Goddard Institute for Space Studies
Year
Baseline: 1951-1980 average
 Assessing Future Temperature Increases

What happens eventually

What happens immediately

AR6 WGI Report: The Physical Science Basis (2021); Fig. 7.18
 Modelling Changes in Temperature

All models have

uncertainties

Wyser et al. (2020) Environmental Research Letters

Nobel Laureate Estimate of Warming Impact
Average person 2020
lives on…
$40
a
day

2100
$170 a $177 a
day day
if 0 C
rise
Energy Poverty is a Major Problem

3 billion people have no

access to electricity or
clean cooking fuels

Major contributor to
early and child mortality
 IPCC Estimate of Consequences
Location is key
• Predicted impacts
vary substantially
• Impact studies
based heavily on
modelling
• Heavily correlated
to wealth / GDP
• Adaptation
Access to energy is feasibility depends
essential on wealth
AR6 WGII Report: Impacts, Adaptation, Vulnerability
Feedback and Runaway

• Warmer temperatures melt ice – reduce reflected radiation

• Warmer temperatures melt permafrost and release
methane from methanogenesis and hydrates
– 1,400 Gt of carbon locked up
– 50Gt release is possible
– Increase atmospheric methane 12 fold
What contributes to
Australia’s high
emissions per
capita?
Analysis of Australia’s Emissions
1.17% Global emissions
0.32% Global Population
35 32.0
30
3.6% Global emissions exported fossil fuel
25
Percentage

20 18.6 18.1
15 12.3
10.7
10
6.2
5
2.2
0
Energy - Energy - Energy - Energy - Industry Agriculture Waste
Electricity Stationary Transport Fugative
Production Emissions

Total domestic production of CO2 equivalent = 436,000,000 tonne

Total global production of CO2 equivalent = 37,120,000,000 tonne
Analysis of Australia’s Emissions
Population (million) 0.4 7.3 0.2 4.6 1.6 0.5 5.6 2.4

Total domestic production of CO2 equivalent = 436Mt

United Kingdom Case Study

• UK CO2 emissions peaked in 1973

• Declined 38% from 1990 to 2017 (latest data)
• Now back to ~1850 levels
• Due to
– Cleaner Electricity generation 36%
– Reduced industry fuel consumption 31%
– Reduced electricity use 18%
– More efficient transport 7%
UK Electricity Generation by Fuel

https://www.carbonbrief.org
UK Non-electric CO2 Emissions

https://www.carbonbrief.org
CO2 Imports and Exports from Trade 2014

Export CO2 Import CO2

Direct Air Carbon Capture and Storage
DACCS (Direct Air Carbon Capture Storage)

• CO2 at 421 ppm in atmosphere

• Basic process is to expose air to large surface area of chemical sorbent
– Absorption – dissolves in sorbent
– Adsorption – adheres to surface of sorbent
• Many different design proposed/pilot scaled
• Two common approaches
– Use fans to push air through a basic solution to absorb CO 2
– Use large surface areas (artificial trees) to ad/ad sorb CO 2
DACCS with Strong Base Sorbents

• Use NaOH or KOH as strong base

• Base reacts with CO2 to form carbonate solution M2CO3 (M = metal)
• Carbonate solution reacted with Calcium hydroxide (Ca(OH)2) to precipitate CaCO3
and regenerate the base
• CaCO3 sent to calciner, reacted with O2 at 800ºC (Concentrated Thermal) to form
CO2 and CaO
• CaO dissolved in water to form Ca(OH)2
Absorption DACCS
Adsorption DACCS

• Use amines as adsorbent

• 2 step process
• First step adsorbs CO2 onto the amine
• Second step uses low temperature, pressure or humidity changes to regenerate
the sorbent
• Uses lower energy than absorption processes due to weaker adsorption bonds
being formed and broken
Adsorption DACCS
Issues with DACCS

• All energy used must come from low carbon sources

• Use of natural gas to run DACCS would produce 70-90% of CO2 DACCS removes
• DACCS more energy intensive than CCS from flue stacks due to reduced
concentration of CO2 in source (300 times less in air than flue gas)
– Requires much greater use of sorbents and associated infrastructure
• DACCS cost estimates USD 100-250/tonne CO2 removed
– Flue based CCS ranges from USD 15 – 120/t CO2

• DACCS can be placed anywhere – not dependent on CO2 source

• Forecast costs of DACCS in 2050 is USD 50/t with cheap solar energy
CCS Cost
Implementation

• ClimeWorks (amongst others) plans are capable of extracting 1Mt / CO 2 / year

• Require 40,000 of these plants to remove current annual CO2 production
• A full life-cycle analysis of the material, energy, and other implications of
constructing and maintaining anything like this vast quantity of plants remains a
major analytical gap.
ORCA

• World’s largest DACCS

• Located in Hellsheidi, Iceland
• Operational September 2021
• Energy from Geothermal
• Cost USD 15,000,000
• 8 x 500 t/a units
• Total 4000 tonnes CO2/annum (4.8 tonnes/person world average)
– Emissions from (235 Australians, 40,000 Ethiopians)
• 1/9,000,000th of annual global CO2 production
• (135 Trillion dollars to remove global emissions) (1.5 size world economy)
Q&A

• Any questions so far?