ENV2D02 Energy Conservation

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ENV-2D02 Energy Conservation 2005 - 06
10. Electricity Conservation
Keith Tovey HSBC Director of Low carbon
Innovation Energy Science Director CRed Project
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10.1 Introduction
Several aspects to consider

• Growth in Population
• greater in last 10 years than previously
• Reduction in Household size
• has fallen from 2.9 to 2.3 in 30 years
• A saving of 17.5 per household by 2020 will not
  reduce demand Will just keep pace with increase
  in demand
• growth in use of appliances and refrigeration
• the issue of STANDBY
• technical improvements leading to more efficient
  use of electricity
• controlling demand for electricity
• fuel switching to electricity

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10.2 Growth in Demand for Electricity

• Demand for electricity was almost static 1972
  1982
• Has risen at 1.8 per annum since
• Consumption is 17 higher than 1997
• 1970 1980
• Increase in demand for appliances and decorative
  lighting
• Compensated by reduction of electric heating
• Much more efficient televisions (solid state vs
  valves)
• 1980 onwards
• Little further opportunity for reduction in
  electric heating
• Increased use of heavy energy users tumble
  dryers etc.
• Further move to more decorative lighting
• Use of cheap halogen bulbs in recent years
• Limited reduction from use of low energy
• Increase from Digital Televisions

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10.3 The Standby Problem

• Appliances do not always switch off even with the
  button!!!

This appliance switches of by pressing button
But this one does not!
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10.3 The Standby Problem
This appliance has to be on otherwise settings
are lost.
This appliance can be switched off as settings
are retained by battery which is recharged on
next use.
See IEA Website Things that go blip in the
night
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10.4 Technical improvements to reduce electricity
consumption

• Electrical appliances nearly 100 efficient in
  converting energy
• motive power, sound, light, heat
• ?? Form of energy required
• Tungsten filament light is 100 efficient -
  but mostly heat
• Fluorescent tubes much more efficient
• CFL consume 20 of energy
• T8 tubes are more efficient than older T12
• Electronic control even better
• LED 25 or less of CFL the light of the future
• Halogen spot lights consume as much as some
  tungsten filament and if multiple use then room
  can consume significantly more
• Microwave/radio frequency heating uses less
  energy as can infra red in some circumstances.
• Improvements in insulation in hot/cold appliances
• Mixed fuel appliances e.g.
• White Knight BG437 Standard Gas Dry Tumble Dryer

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10.4.1 Power Factor Correction

• Tungsten filament lights have little reactive
  load.
• Machinery (fluorescent lights) waste energy
  reactive load
• 20-30 of energy is lost
• Alternative current Line voltage is /- 340
  50 Hz.
• Root Mean Square (RMS) volts is 240

• DC Power volts x amps
• For a power of 1 kW
• Current 1000/240 4.17 amps.
• AC situations
• Current and volts often out of phase
• power volts x amps cos ?
• is the phase angle,
• cos ? is the power factor.

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10.4.1 Power Factor Correction

• Typical values of ? 30 50o
• cos ? 0.8
• 20 loss
• Resistive loads have current in phase with
  voltage
• Inductive loads have current lagging behind phase
  of voltage
• Capacitive loads have current leading phase of
  voltage.
• Can compensate for power factor by including a
  device of the opposite type to compensate
• Must be carefully matched.

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10.5 Controlling the demand for electricity

• 10.5.2 Meeting the demand for electricity

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10.5 Controlling the demand for electricity

• 10.5.2 Meeting the demand for electricity

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10.5 Controlling the demand for electricity

• 10.5.2 Meeting the demand for electricity
• Dinorwig Power Station 25th May 2005

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10.5 Controlling the demand for electricity

• Meeting the short term fluctuations

• Pumped Storage 10 seconds
• Hydro 10 90 seconds
• Open Circuit Gas Turbine - 2 to 3 mins
• Interconnector to France
• New interconnector to Norway
• Balancing Mechanism operation
• Running under low load pick up / run down
  at rate of 8 MW per minute per set
• Consequence of NETA / BETTA

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10.5 Controlling the demand for electricity

• 10.5.3 Shifting Demand

• .1. the day time peak
• Fossil fuel power station take up to 24 hours to
  come on line
• Run these continuously where possible
• might have to be brought up for load
  and then not used.
• Encourage people to switch from peak to night
  time use.
• Use pump storage schemes to pump water up at
  times of low demand increasing utility of
  fossil fuel power stations.
• May not save if electric storage heaters are
  used.
• 2) the short term transient peak
• arising primarily from TV scheduling.
• Use pump storage

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10.5 Controlling the demand for electricity

• 10.5.4 Financial Incentives to Switch Demand

• Economy 7 (10) Tariffs
• Lower night time rates but higher day time rates.
  
• Need to use at least 15 overnight ot make it
  worthwhile

10.5.5 Financial incentives to deter use of
electricity at peak periods
1) Maximum Demand Tariffs 2) Seasonal
Tariffs 3) Time of Day Tariffs 4) Tariffs which
vary according to other factors.
Maximum Demand Tariffs tariff as of 1999 1) A
standing charge for each month 92.92 charge
for use of the system 2) An availability charge
1.03 per kVA of potential demand There is
also a charge for units consumed in the 30 minute
period of maximum demand during the month. This
varies according to month March -
October NIL
November and February 2.17
December and January 6.92 A unit charge
(midnight to 7 am) 2.45p Units at
other times of day
5.32p A REACTIVE POWER charge for each kiloVAR
0.18p in excess of half the number of units
supplied
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Maximum Demand Tariffs tariff as of 1999
1) A standing charge for each month 92.92
charge for use of the system 2) An availability
charge 1.03 per kVA of potential demand A
charge for units consumed in the 30 minute period
of maximum demand during the month. This varies
according to month March -
October
NIL November and February
2.17 December and
January 6.92 A unit charge
(midnight to 7 am)
2.45p Units at other times of day
5.32p A REACTIVE
POWER charge for each kiloVAR 0.18p in
excess of half the number of units supplied if
power factor falls below 0.895
Note Maximum Demand Tariff is 130 times normal
rate gtgtgt in December and January 25 30 of
electricity bill could come from a single 30
minutes period
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10.5 Controlling the demand for electricity

• Seasonal Tariffs
• e.g. Arizona Public Service 400 kWh /
  month
• Time of Day Tariff
• An extension of the Economy 7 tariff
• Salt River Project
• Up to 5 different tariffs during the day
• Radio/Computer technology could be used to
  display varying tariffs in the kitchen
• Tariffs according to other factors
• South Carolina uses mean temperature as the key
  to tariffs.
• Charges are higher when temperature exceeds 26oC

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10.5.6 Load Management Schemes

• Large Consumers - usually much larger than UEA
• Electricity Supply industry to directly control
  demand
• Supplier requests that a consumer shed a given
  amount of load
• Typically the load management time is for no more
  than 2 hours on any one day
• with a maximum of say 100 hours in a year.
• Consumer gets a significant discount, but
  discount depends on length of warning
• best tariffs for consumers prepared to have only
  15 minutes warning of a load management shedding.
  
• Scheme is attractive to the Electricity Supply
  Industry
• Directly tackles the problem of the peak demand,
  
• 1GW or more of load have been shed in this way.
• Small/Domestic Consumers
• Little done in UK
• 1980 Florida Power experimented with radio
  control of
• 1. Central heating
• 2. Air-conditioning
• 3. Swimming pool filtration plants

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10.5.6 Load Management Schemes

• Other possible ideas for Load Management.
• microprocessor switching devices controlled to
  selectively shed load at peak times in a
  consumers premises,
• As above but restrict load to a given amount at
  peak times say 1000W.
• microprocessor devices to alter the tariff
  structure during the day
• reflecting the marginal cost of generating
  electricity at that time of day.
• multiple rate tariff at any time during day
• Possibilities in Dongtan

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10. Other methods to reduce demand

• Rescheduling TV adverts etc
• More direct relationship between use and payment
  for energy
• 3 month readings in arrears
• Direct debit
• Are disincentives to promoting energy
  conservation
• Smart Cards
• Reverse Tariffs e.g. IrkutskEnergo

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A Paradox Effective Energy Conservation will
lead to an increase in Electricity Consumption

• Industrial Processes
• Drying (a heat pump is much more efficient)
• Air-knife
• Dehumidifying
• Case Hardening
• Inductive heating
• Space heating with heat pumps

• Other reasons for increase in electricity
  consumption
• Move to electric vehicles
• Move to hydrogen economy
• Increase in population
• Decrease in household size.

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Our Choices They are difficult

• Do we want to exploit available renewables i.e
  onshore/offshore wind and biomass.
  Photovoltaics, tidal, wave are not options for
  next 20 years.
• If our answer is NO
• Do we want to see a renewal of nuclear power
• Are we happy on this and the
  other attendant risks?

• If our answer is NO
• Do we want to return to using coal?
• then carbon dioxide emissions will rise
  significantly
• unless we can develop carbon sequestration
  within 10 years which is unlikely

If our answer to coal is NO Do we want to leave
things are they are and see continued
exploitation of gas for both heating and
electricity generation? gtgtgtgtgtgt
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Our Choices They are difficult

• If our answer is YES
• By 2020
• we will be dependent on around 70 of our
  heating and electricity from GAS
• imported from countries like Russia, Iran,
  Iraq, Libya, Algeria
• Are we happy with this prospect? gtgtgtgtgtgt

If not We need even more substantial cuts in
energy use. Or are we prepared to sacrifice our
future to effects of Global Warming? - the
North Norfolk Coal Field?
Do we wish to reconsider our stance on
renewables? Inaction or delays in decision making
will lead us down the GAS option route and all
the attendant Security issues that raises.
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Our Choices They are difficult
A diverse renewable supply will be local, and
will be less prone to cascade power cuts such as
those recently in US, London, Italy,
Denmark. Conventional generation is based on
large units 500 660 MW enough to supply over
1 million homes. These do fail from time to
time, and require much greater backup than
required for the failure of a few wind turbines.
A reactor trip at Sizewell B has an even larger
effect 1188 MW. Renewable generation is less
prone to major interruption
Local Small Scale generation saves 8.5 from
losses in transmission An important advantage
over conventional generation or far Offshore Wind
We must not get drawn into a single issue debate
a rational debate covering all the
alternatives is needed. Available Renewables
Nuclear Conservation
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Historic and Future Demand for Electricity
Number of households will rise by 17.5 by 2025
and consumption per household must fall by this
amount just to remain static
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Electricity Options for the Future
The Gas Scenario Assumes all new non-renewable
generation is from gas. Replacements for ageing
plant Additions to deal with demand
changes Assumes 10.4 renewables by 2010
20 renewables by 2020

• High Growth Business as Usual
• Low Growth capped at 420 TWH by 2010

• Rise in emissions 2005 2010
• loss of nuclear generating capacity
• Fall in 2010 2020
• loss of nuclear and coal capacity
• Little new generating capacity available before
  2010 except Wind

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Electricity Options for the Future

• Low Growth Scenario
• Capped at 420 TWh
• 33 CO2 reduction (Gas) cf 1990
• 62 CO2 reduction (Nuclear) cf 1990
• 68 increase in gas consumption
• ( Gas Scenario) cf 2002
• Mix option 6 new nuclear plant by 2025
• Mix option 11 increase in gas
• consumption (cf 2002)

• High Growth Scenario
• Business as Usual
• 0.3 CO2 reduction (Gas) cf 1990
• 54 CO2 reduction (Nuclear) cf 1990
• 257 increase in gas consumption
• ( Gas Scenario) cf 2002

• 25 Renewables by 2025
• 20000 MW Wind
• 16000 MW Other Renewables inc. Tidal, hydro,
  biomass etc.

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Conclusions

• Global Warming will affect us all - in next few
  decades
• Energy Security will become increasingly
  important. Inaction over making difficult
  decisions now will make Energy Security more
  likely in future.
• Move towards energy conservation and LOCAL
  generation of energy
• It is as much about the individuals response
  to use of energy as any technical measures the
  Government may take.
• Wind (and possibly biomass) are the only real
  alternatives for renewable generation in next 5
  10 years.
• Otherwise Nuclear??? but Uranium
  resources are limited
• We need to have a multi-pronged approach we
  need all available renewables, much more
  conservation, and possibly some nuclear.
• Even if we are not convinced about Global Warming
  Energy Security issues will shortly start to
  affect us.

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Conclusions
Lao Tzu (604-531 BC) Chinese Artist and Taoist
philosopher
"If you do not change direction, you may end up
where you are heading."