ENERGY CONVERSIONMME 9617a

Eric Savorywww.eng.uwo.ca/people/esavory/

mme9617a.htm

Lecture 1 - Introduction

Department of Mechanical and Material EngineeringUniversity of Western Ontario

Today’s class will cover:

● Outline of the course and course project

● A brief history of energy sources and energy usage ● World population growth and energy demand

● Introduction to some present day numbers and challenges

Course Objectives

● To introduce the basic technical and economic criteria for the design of efficient energy conversion systems, including traditional as well as alternative power systems

● To discuss strategies for increased energy efficiency and more environmentally sound operation

● To assess design alternatives and selection criteria, based on long-term economic viability and overall energy management strategies

Topics

● Introduction to energy conversion● Economic considerations in energy production ● Fuels● Review of basic theory● Thermal energy (e.g. heat exchangers)● Mechanical energy (e.g. pumps, turbines)● Heat pumps● Solar power● Nuclear power● Fuel cells● Wind and wave

The course grade will be based on termwork:

Assignments (30%)

Term research project report and presentation (70%)

Assessment

The Norfolk BroadsEast Anglia, England

By the 12th century, much of East Norfolk had been cleared of its woodland for fuel and building materials

The first written evidence of peat digging for fuel in the Broads also dates from this time

Between the 12th and 14th centuries peat digging (or turf cutting) was a major industry

Peat diggings were abandoned by the 14th century because they kept filling with water. They flooded, and this man-made landscape became a wetland, rich in wildlife.

Now it is a major tourist and vacation area ….

A brief history of energy sources and energy usage

It all started with wood and peat ……

Wood

Electricity

Coal

Oil

Nuclear

Transportation

Those are the main energy sources but what are they used for ?

Transportation

Energy Uses have changed …

Energy consumption in the USA (1775 – 1999)

World population growthand energy demand

World population (1,000s)?

Likely to peak at 10 - 16 bn

Are there limits?

Science, 162, 1243-1248

“The Population Bomb”

100 1,000 10,000 100,000

Annual income per capita $ US

Percentage shares of world population, world GDP* andworld commercial energy consumption for selected countries

* GDP – Gross Domestic Product

Carbon emission factors from energy use

* British Thermal Unit - defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. Melting a pound of ice at 32 °F requires 143 BTU.

CO2 = Pop x (GDP / pop) x (Btu / GDP) x (CO2 / Btu) – Seq

- GDP / pop represents standard of living- Btu / pop represents energy intensity- CO2 / pop represents carbon intensity

- Seq accounts for sequestered CO2

* Organization for Economic Co-operation and Development

Edmonds J, Energy Policy

23, 4 – 5 (1995)BP Statistical Review of

World Energy (2000)

Introduction to some present day numbers and challenges

21st century trends

• Increase in population leads to increasing demand for energy

• Interest in developing local energy resources grows

• Environmental and health concerns increase on all scales

• Increased electrification

• Infrastructure security concerns increase

The numbers are huge !

• Population 6,000,000,000• Land area 58,000,000 sq miles• Population density 100+ people / sq mile• Annual energy consumption 400 Quads

– oil equivalent 72,000,000,000 bbl– coal equivalent 14,400,000,000 tonnes

• Registered car and trucks 700,000,0000• Electric generating capacity 3,000,000 MW• Annual steel production 650,000,000 tonnes• Annual aluminium production 20,000,000 tonnes• Annual cement production 1,500,000,000 tonnes

Progressing towards asymptotic ?• Population -6+ billion growing to 10 to 15+

billion (?)

• Total primary energy –– 400 quads growing to 2000+ quads annually (1 quad = 1015 Btu)– 73 billion growing to 365+ billion bbl of oil/yr

• Per capita energy per year – 10 BOE/yr-person growing to 25 BOE/yr-person

• Number of cars and trucks –– 750 million now growing to 5 + billion

• MW electric generating capacity -– 3.5 million MW now growing to 15+ million MW

Other global concerns

• Carbon emissions may be affecting climate

• Health concerns over other emissions are growing

• Global fossil energy resources are not uniformly distributed

* http://cohesion.rice.edu/NaturalSciences/Smalley/emplibrary/120204%20MRS%20Boston.pdf

TOP 10 GLOBAL CONCERNS

2003

2050

Solutions:

Find alternatives to oil

Solar energy etc

Transport energy as energy, not as mass

Nanotechnology local energy storage (e.g. 100 kW)

High voltage long distance transmission (100s GW rather than 1GW)

Total primary power requiredFor IPCC BAU scenarioEnergy

sources& demand

M I Hoffert et al,Nature, 395,881 – 4 (1998)

WRE = Wigley,Richels andEdmonds,ppmv of CO2.

Pre - industriallevel is 350ppmv

Energy questions

• Can we satisfactorily reduce emissions and remediate wastes residing in our water and air basins?

• Can we offset changes being introduced by our consumption of fossil fuels?

• Can we significantly reduce our dependence on imported oil?

• Can nuclear, renewable, and other non-fossil energy resources be deployed quickly enough to make a difference?

End use of energy forms

• Thermal

• Electrical

• Electromagnetic

• Chemical– fuels for transportation– fuels for industrial processes

• Electrochemical

• Mechanical ( KE or PE ) for power

Primary energy sources

• Nuclear fission and fusion

• Solar radiation

• Chemical reactions, e.g. combustion of fossil and biomass fuels

• Gravitational forces, planetary motion, and friction ( tides, waves and wind)

Energy rate scaling

• Food 250 kcal / candy bar • Average daily requirement 2000-3000 kcal / day = 100 W• Human heart 2 W• Running 500 W• 1 horsepower 750 W• 747 jet plane 250 MW• Automobile 100 kW• Space shuttle (with boosters) 14 GW• Typical electric gen. plant 1000 MW• 1 wind turbine 1-3 MW• Laptop computer 10 W• Cell phone 2 W

US energy consumption per year: 3.5 TWWorldwide energy consumption per year: 15 TW

Sustainable energy technologycharacteristics

• Non-depletable on a short time scale• Low impacts on natural resources - land, water, etc.

across process life cycle• Accessible and well distributed – available close to

demand• Emissions free – no NOx, SOx, CO2, particulates etc. • Scalable – from 1 kW to 1,000 MW• Dispatchable - for base load, peaking and distributed

needs• Robust - simple, reliable, durable and safe to operate • Flexible - applications for electricity, heat, and co-gen• Competitive economically

Energy supply options• Earth based energy

– Conventional fossil fuels (coal, oil, natural gas)– Unconventional fossil fuels (oil shale, tar sands) – Nuclear fission – uranium, etc.– Hydropower – Geothermal heat

• Ocean based energy– Tidal– Waves

• Solar based energy– Solar thermal– Photovoltaics– Wind– Biomass

Millions of Tons of CO2 emitted per Quad (1015 BTU)

Fossil and nuclear options

• Fossil – oil and gas resources are depletable and maldistributed worldwide and carbon sequestration will be costly and not a permanent solution

• Fissile – no carbon emissions but wastes, proliferation and safety remain as dominant public acceptance issues

• Fusion – technology not ready with uncertain costs and performance

Renewable energy technologies have high sustainability index scores– Solar– Wind– Biomass– Geothermal– Hydro

Costs relative to fossil fuels remain high

‘Playing by the rules’

• The Laws of thermodynamics are relevant !!

• Heat and electric power are not the same

• Conversion efficiency does not have a single definition

• All parts of the system must work – fuel supply, fuel and energy converters, control and monitoring sub systems, and the interconnection if required

Seek collateral opportunities

• Combined heat and power (co-generation) to increase resource utilization efficiency

• Integrated high efficiency building designs

• Hybrid energy use with distributed generation

• Manufacturing processes that use less materials and energy

Energy chains• Locating a source – solar, fossil, geothermal,

nuclear

• Recovery and/or capture

• Storage of a resource, or storage due to the intermittency of a renewable energy supply

• Conversion, upgrading, refining, etc.

• Storage as a refined product

• Transmission and distribution

• Use and re-use

• Dissipation as degraded energy and/or wastes

Resource assessment• Global energy resources are not uniformly

distributed and vary widely in quality

• Characterization inadequate for developed countries and very poor for developing countries

• Energy resource bases and energy reserves are not the same

• New technology enhancements exist to significantly improve resolution and quantification of assessments

• Resource assessment is under-valued and under-supported nationally and internationally

Global resources basesEstimating resource bases is highly uncertain –(i) for mineral-based resources like oil, gas, and coal –

dependence on technology and has limited data.(ii) for renewables land-use and capture efficiency are

critical

Historical energy prices

Price vs. cost vs. value

• 1 litre of gasoline = $ 0.50• 1 litre of gasoline without tax = $ 0.35• 1 litre of liquid hydrogen = $ 0.85• 1 litre of bottled water = $1.00• 1 litre of milk = $ 1.50• 1 litre of orange juice = $ 3.00• 1 litre of Dom Perignon 1995 = $ 150.00• 1 litre Ralph Lauren aftershave = $ 450.00• 1 litre of Chanel #5 perfume = $ 12,000.00

Courtesy of MIT website

Next week:

Definitions of energy and the economic considerations in energy production

Details of the Individual Term Project

Report: 50% of course grade

Presentation: 20% of course grade

Objective

To improve your knowledge of a specific area of energy conversion analysis by providing an individual project report concerning a critical appraisal of an energy conversion process (or series of linked processes) in which you will examine current practice including example calculations, the process efficiencies and alternative strategies for achieving the same practical outcome, against a background of the need to reduce local and global carbon emissions.

To present the project to the class, including answering questions from the audience.

To provide a final report.

Topic Selection

Firstly, you should select your topic from one of the following sectors:

1.Energy production, storage and transmission

2.Transportation (e.g. road vehicles, rail vehicles, aircraft, ships)

3.Manufacturing industry (e.g. raw materials processing, finished product manufacturing)

4.The built environment (e.g. houses, roads, tall buildings, bridges)

Researching the literature

Then, within that sector choose a specific energy conversion process or linked processes.

You will then need to identify and obtain the key papers relating to your chosen topic as these will form the basis of your discussion. A minimum of 10 papers must be included in your discussion, at least 5 of which should be journal papers. It is useful if you can identify a recent review paper as this will help you find the key publications.

Next weeks class: Engineering librarian will give a talk on research strategies for this course

Deadlines

Before Wednesday 24th September – Choose topic and e-mail me title and brief outline of proposed area of research

Before the next class - I will e-mail you with comments concerning your proposal so you can start detailed work

Wednesday 26th November - Paper copy of your final report due (11 weeks from today!)

5 pm on Tuesday 18th November – Powerpoint presentation file to be e-mailed or given to me

19th and 26th November – Presentations (15 minutes) in class time slot to be attended by all students registered on the course