ENV1A80 Environment and Society - PowerPoint PPT Presentation

1 / 31
About This Presentation
Title:

ENV1A80 Environment and Society

Description:

N.K. Tovey (???) M.A., PhD, CEng, MICE, CEnv. ?.?.???? ?.?., ?-? ??????????? ???? ... 'Dammed' to harvest. wind. NUCLEAR. CHEMICAL - fuels:- gas, coal, oil etc. ... – PowerPoint PPT presentation

Number of Views:32
Avg rating:3.0/5.0
Slides: 32
Provided by: Env54
Category:

less

Transcript and Presenter's Notes

Title: ENV1A80 Environment and Society


1
ENV-1A80 Environment and Society 2005 - 06
Introduction
N.K. Tovey (???) M.A., PhD, CEng, MICE,
CEnv ?.?.???? ?.?., ?-? ??????????? ???? Energy
Science Director CRed Project
2
(No Transcript)
3
(No Transcript)
4
Course Work
A Group Project partly individual, partly
group Assessment of Energy Labelling on White
Goods and Lighting
5
1.1 INTRODUCTION
  • In UK each person is consuming energy at a
    rate of
  • 5kW
  • In USA it is 10 kW
  • 1/20th or Worlds Population
  • consumes 25 of all energy
  • In Europe it is 5.7 kW
  • Globally it is around 2kW
  • ENERGY Consumption gt Carbon Dioxide gt Global
    Warming

6
1.1 INTRODUCTION
Nuclear Fusion ??
7
Future Global Warming Rates
8
Reasons for Concern
Range of predicted temperatures
Risks to Many
Large Increase
Net Negative for all markets
Negative for most Regions
Higher Risk
Some positive/ some negative Most people
adversely affected
oC
Current temperature
Negative for some Regions
Risks to Some
Very Low Risk
Increase
I II III IV
V
Historic Average
Average 1950 - 1970
I Risks to Unique and Threatened Systems II Risks
from Extreme Climatic Events III Distribution of
Impacts IV Aggregate Impacts V Risks from Future
Large Scale Discontinuities
9
1.1 INTRODUCTION
How much Carbon Dioxide is each person emitting
as a result of the energy they use? In UK 9
tonnes per annum. What does 9 tonnes look
like?
Equivalent of 5 Hot Air Balloons! To combat
Global Warming we must reduce CO2 by 60 i.e.
to 2 Hot Air Balloons How far does one have to
drive to emit the same amount of CO2 as heating
an old persons room for 1 hour? 1.6 miles
10
1.1 INTRODUCTION
  • Consequences of Global Warming
  • Increased flooding in some parts
  • Increased incidence of droughts
  • Increased global temperatures
  • General increase in crop failure, although
    some regions
  • may benefit in short term
  • Catastrophic climate change leading to next
    Ice Age.
  • Energy must be studied from a multi-disciplinary
    standpoint

11
What is CRed doing - will you become a partner?
Will you pledge to reduce Carbon Dioxide? The
pledge might be a small challenge, it might be a
large one. To encourage you a 5 bonus will be
given to part of course work for those
successfully pledging. Visit the CRed
Website www.cred-uk.org
12
UEA Heat Pump
13
In 1974 Bramber Parish Council decided to go
without street lighting for three days as a
saving. ( this was during a critical power
period during a Miners Strike). Afterwards,
the parish treasurer was pleased to announce
that, as a result electricity to the value of
11.59 had been saved. He added, however, that
there was a bill of 18.48 for switching the
electricity off and another of 12.00 for
switching it on again. It had cost the council
18.89 to spend three days in darkness.
An example of where saving resources and money
are not the same
14
What is wrong with this title?
From the Independent 29th January 1996 similar
warning have been issued in technical press for
this winter
15
1.2 THE ENERGY CRISIS - The Non-Existent Crisis
  • No shortage of energy on the planet
  • Potential shortage of energy in the form to which
    we have become accustomed.
  • Fossil fuels
  • FUEL CRISIS.

16
1.3 HISTORICAL USE OF ENERGY up to 1800
  • 15 of energy derived from food used to
    collect more food to sustain life.
  • energy used for
  • making clothing, tools, shelter
  • Early forms of non-human power-
  • 1) fire
  • 2) animal power
  • OTHER ENERGY FORMS HARNESSED
  • 1) Turnstile type windmills of Persians
  • 2) Various water wheels (7000 in UK by
    1085)
  • 3) Steam engines (?? 2nd century AD by
    Hero)
  • 4) Tidal Mills (e.g. Woodbridge, Suffolk
    12th Century)

17
1.4 The First Fuel Crisis
LONDON - late 13th /early 14th Century ? Shortage
of timber for fires in London Area ? Import of
coal from Newcastle by sea for poor ? Major
environmental problems -high sulphur content
of coal Crisis resolved - The Black Death.
18
1.5 The Second Fuel Crisis-
UK - Late 15th/early 16th century ? Shortage of
timber - prior claim for use in
ship-building ? Use of coal became widespread
-even eventually for rich ? Chimneys appeared to
combat problems of smoke ? Environmental lobbies
against use ? Interruption of supplies - miner's
strike ? Major problems in metal industries led
to many patents to produce coke from coal
(9 in 1633 alone)
19
1.6 Problems in Draining Coal Mines
Problems in Draining Coal Mines and Transport of
coal gt threatened a third Fuel Crisis in
Middle/late 18th Century Overcome by
Technology and the invention of the steam engine
by Newcommen. ? a means of providing substantial
quantities of mechanical power which was not
site specific (as was water power
etc.). NEWCOMMEN's Pumping Engine was only 0.25
efficient
WATT improved the efficiency to 1.0
20
1.6 Current Limitations
Current STEAM turbines achieve 40 efficiency,
  • further improvements are
  • LIMITED PRIMARILY BY PHYSICAL LAWS
  • NOT BY OUR TECHNICAL INABILITY TO DESIGN AND
  • BUILD THE PERFECT MACHINE.

Coal fired power stations ultimate efficiency
45 even with IGCC CCGT Stations are
currently 47-51 efficient gt ultimately
55.
21
1.7 Energy Capabilities of Man
  • Explosive sports - e.g. weight lifting
  • 500 W for fraction
    of second
  • Sustained output of fit athlete --gt 100 - 200
    W
  • Normal mechanical energy output ltlt 50 W
  • Heat is generated by body to sustain body at
    pre-determined temperature-
  • Thermal Comfort
  • approx. 50 W per sq. metre of body area when
    seated
  • 80 W per sq. metre of body area
    when standing.

22
Early Wind Power Devices
  • C 700 AD in Persia
  • used for grinding corn
  • pumping water
  • evidence suggests that
  • dry valleys were
  • Dammed to harvest
  • wind

23
1.8 Forms of Energy
  • ? NUCLEAR
  • ? CHEMICAL - fuels- gas, coal, oil etc.
  • ? MECHANICAL - potential and kinetic
  • ? ELECTRICAL
  • ? HEAT - high temperature for processes
  • - low temperature for space
    heating
  • All forms of Energy may be measured in terms of
    Joules (J),
  • BUT SOME FORMS OF ENERGY ARE MORE EQUAL THAN
    OTHERS

24
1.9 ENERGY CONVERSION
  • ? Energy does not usually come in the form
    needed
  • ? convert it into a more useful form.
  • ? All conversion of energy involve some
    inefficiency-
  • ? Physical Constraints (Laws of Thermodynamics)
  • can be very restrictive
  • MASSIVE ENERGY WASTE.
  • ? This is nothing to do with our technical
    incompetence. The losses here are frequently in
    excess of 40

25
1.9 ENERGY CONVERSION
  • ? Technical Limitations
  • (e.g. friction, aero-dynamic drag in
    turbines etc.) can be improved, but losses here
    are usually less than 20, and in many cases
    around 5.
  • ? Some forms of energy have low physical
    constraints
  • converted into another form with high
    efficiency (gt90).
  • e.g. mechanical lt--------gt electrical
  • mechanical/electrical/chemical
    -----------gt heat
  • ? Other forms can only be converted at low
    efficiency
  • e.g. heat ------------gt mechanical power -
    the car!
  • or in a
    power station

26
1.9 ENERGY CONVERSION
  • USE MOST APPROPRIATE FORM
  • OF ENERGY FOR NEED IN HAND.
  • e.g. AVOID using ELECTRICITY for
  • LOW TEMPERATURE SPACE heating
  • Hot Water Heating
  • Cooking (unless it is in a MicroWave).

27
1.10 WHAT DO WE NEED ENERGY FOR?
  • ? HEATING - space and hot water demand
  • (80 of domestic use excluding
    transport)
  • ? LIGHTING
  • ? COOKING
  • ? ENTERTAINMENT
  • ? REFRIGERATION
  • ? TRANSPORT
  • ? INDUSTRY
  • - process heating/ drying/ mechanical
    power
  • IT IS INAPPROPRIATE TO USE
  • ELECTRICITY FOR SPACE HEATING

28
1.11 GRADES OF ENERGY
  • ? HIGH GRADE
  • - Chemical, Electrical,
    Mechanical
  • ? MEDIUM GRADE - High Temperature Heat
  • ? LOW GRADE - Low Temperature Heat
  • All forms of Energy will eventually degenerate to
    Low Grade Heat
  • May be physically (and technically) of little
    practical use - i.e. we cannot REUSE energy which
    has been degraded
  • - except via a Heat Pump.

29
1.12 ENERGY CONSERVATION
  • Energy Conservation is primarily concerned with
    MINIMISING the degradation of the GRADE of
    ENERGY.
  • (i.e. use HIGH GRADE forms wisely
  • - not for low temperature heating!!).
  • To a limited extent LOW GRADE THERMAL ENERGY may
    be increased moderately in GRADE to Higher
    Temperature Heat using a HEAT PUMP.
  • However, unlike the recycling of resources like
    glass, metals etc., where, in theory, no new
    resource is needed, we must expend some extra
    energy to enhance the GRADE of ENERGY.

30
(No Transcript)
31
Reasons for Concern
Range of predicted temperatures
Risks to Many
Large Increase
Net Negative for all markets
Negative for most Regions
Higher Risk
Some positive/ some negative Most people
adversely affected
oC
Current temperature
Negative for some Regions
Risks to Some
Very Low Risk
Increase
I II III IV
V
Historic Average
Average 1950 - 1970
I Risks to Unique and Threatened Systems II Risks
from Extreme Climatic Events III Distribution of
Impacts IV Aggregate Impacts V Risks from Future
Large Scale Discontinuities
Write a Comment
User Comments (0)
About PowerShow.com