Transcript Key questions 3.3 + 3.4

UNIT 4 Sustainability
Theme 3
Sustainable Energy
Key Question 3.3
How can the demand for energy be managed
sustainably?
•Alternative sources.
•Greater efficiency.
•Demand reduction.
Key Question 3.4
Can a Sustainable energy supply be maintained in
the future?
Draw together above points (from Key Questions
3.1, 3.2, and 3.3) to critically assess attitudes
towards the sustainability of energy supplies.
Key Question 3.3
How can the demand for energy be
managed sustainably?
• Alternative sources.
• Greater efficiency.
• Demand reduction.
Alternative Sources
Renewable sources such as:
• HEP (Hydroelectric power)
• Wave power
• Tidal power
• Wind power
• Solar power
• Bio energy / biomass
• Geothermal
Another alternative source is nuclear power
Alternative Sources
Why should we use renewable energy sources?
.
Environmental reasons
•To reduce greenhouse gas emissions (to help combat
global warming)
•To reduce the creation of low level ozone (due to nitrous
oxides) which is a pollutant and can cause respiratory
problems.
•To stop sulphur dioxide and nitrogen oxides contributing to
the acidification of precipitation (acid rain). This can also
contribute to global warming by killing trees.
Alternative Sources
Why should we use renewable energy
.
sources?
Political reasons
•To get “green-minded” people to vote for a
specific political party (green voters).
•To keep some sources such as nuclear power
competitive.
•To make a country as self sufficient as possible
in energy supply. Over dependence on one
type of fuel can cause problems e.g. Gulf War
affecting oil supplies in 1991.
•To maintain diversity of supply (once again to
stop over dependence on one type of fuel and
the problems this can cause).
Alternative Sources
Why should we use renewable energy sources?
.
Economic reasons
•As a fuel becomes scarcer, its price will rise.
•As world population rises, energy use per capita will have
to decrease to maintain current levels of production.
Eddington Report
• The “Eddington Transport Study” by Sir Rod Eddington
was published on December 1st 2006.
• It is a report on the impact of transport decisions on the
economy and environment of the UK along with
recommendations on how the transport network should
be modernised.
Conclusions
• The UK’s transport network is broadly adequate. There
is no need for new infrastructure such as high speed rail
links and cross country motorways.
• The government should concentrate on improving
existing road and rail networks – to ease pressure in
certain areas.
• Priority should be given to growing cities, parts of the
network vital to economic success, ports and airports.
Eddington Report
• The full cost to the environment, including contributions
to climate change, should be paid by all modes of
transport.
• It supports the gradual introduction of road pricing.
• It also supports the reformation of the planning system to
speed up the building of infrastructure projects.
• The air transport industry needs to become sustainable,
possibly by requiring air passengers to pay their “full
environmental costs” and there is an economic case for
more runway capacity.
• Due to falling passenger numbers, there is a case for
improving the bus market outside of London by
strengthening competition.
Carbon Trading
• A “pollution credit system” created as part of the
Climate change Protocol signed at Kyoto, Japan
in 1997.
• The first gas to be reduced using this system will
be carbon dioxide.
• The carbon credit system will allow countries to
offset polluting activities.
• Major carbon dioxide polluters (mainly MEDCs)
can buy ‘carbon credits’ from less polluting
countries.
Carbon Trading
How does the system work?
• Each country is given an annual carbon dioxide
pollution limit.
• The system aims to reduce atmospheric
pollution to 1990 levels
• Countries that exceed their limit must do one or
a mixture of the following:
 Paying a fine;
 Paying for ways to reduce domestic carbon
dioxide emissions;
 Buying a proportion of the ‘unused' pollution
from a country which is not exceeding its annual
pollution limits.
Carbon Trading
Will this system work?
It seems like a good idea on paper.
• Financial penalties and influencing how the rest
of the world sees them encourage countries to
reduce emissions.
• It gives countries time to reduce their emission
levels.
• Pollution credit systems have a history of
success e.g. US sulphur dioxide credit system
had reduced sulphur dioxide pollution 50% by
1998.
• System has been put into practice.
Carbon Trading
Will this system work?
Problems
• It allows polluting countries to go on polluting. They buy
themselves out of trouble instead of working on reducing
their emissions.
• The choice to reduce levels to those of 1990 is not
based on anything. What is a “safe” level?
• Planting trees has a limit as the land available to do it will
run out.
• Countries essentially monitor themselves therefore there
is room for cheating and ‘massaging the figures’.
• Some argue that the system serves the need of the
MEDCs.
The best thing is to try and make the system work.
Carbon Trading
International co-operation
•World leaders met in Kyoto, Japan to try and agree on
how to tackle climate change. Many developed nations
agreed to reduce their emissions of greenhouse gases by
5% below 1990 levels. This agreement is called The
Kyoto Protocol.
•Some countries such as China and India are increasing
their emissions. They argue it is necessary to create
power to create wealth (and get rid of poverty).
The EU
• In 2008, the members of the EU agreed two new
targets:
• To reduce CO2 emissions by 20% of their 1990
levels by the year 2020 )mainly by investing in
renewable energy production).
• For each state to source at least 10% of its
transport fuel from biofuel (made from plant
oils). It is considered to be carbon neutral
because these quick growing crops absorb as
much carbon from the atmosphere as they grow
as they give off when they are burnt as fuel.
International co-operation
• An International Climate Change
Conference was held at Copenhagen,
Denmark in December 2009.
Electricity use in homes (domestic)
• The UK’s 25 million homes emit over 40
million tonnes of carbon every year (just
under 30% of the UK total).
• Energy consumption in the domestic
sector is rising by an average 1% a year.
Increasing demand outstrips our attempts
at conservation.
• UK homes are some of the least energy
efficient in Europe.
Electricity use in homes (domestic)
• 60% of energy used in homes is for
heating. Insulating buildings and making
them more airtight could halve that.
• Providing people with information and
financial incentives when they move house
could improve the situation.
• 20% of energy used in homes is for
heating hot water. There are more
efficient ways of doing this e.g. solar
heating of water before it goes into the
boiler.
Electricity use in homes (domestic)
• 15% of energy used in homes is for
lighting and appliances (this is the fastest
growing area). EU legislation has
introduced the A-G energy label. This
approach could be extended but regulation
finds it hard to keep up with technological
change and advancements.
• Final 5% is used in cooking. This does not
seem to change much. There has been
the growth of some new appliances such
as bread makers.
Electricity use in homes (domestic)
How can energy use be reduced?
• Demand reduction strategies only
enough for two thirds of the 60%
reduction the government wants. The
remaining third must come from lowand zero-carbon technologies.
• Less houses will have their own central
heating boiler relying instead on a
community heating scheme or a
domestic combined heat and power
unit.
• Wood and other plant-derived fuels
could be used.
• Areas without mains gas could use
heat pumps (devices that use electricity
to compress low-grade heat from
outdoors into a comfortable
temperature for indoors).
Electricity use in homes (domestic)
How can energy use be
reduced?
• Solar water heaters (roof
mounted plates or vacuum
tubes which use daylight to
heat water).
• Photovoltaic solar panels on
rooftops.
• Small wind turbines.
• Any large scale change
needs government support
strong policies and financial
incentives).
• The role of individuals will
be important in the future.
People will need to be able
to understand and be able
to control new technologies.
LCD v CRT energy demand
• These are technologies used in TVs
and monitors. LCD = Liquid Crystal
Display. CRT = Cathode Ray Tube
(old type of TV).
• LCD uses up to 60% less energy
while running and on standby. E.g.
PC monitor uses 85 – 95 watts when
running and 6 watts on standby. 15”
LCD 25w when operational and 3w
on standby. Could lead to a £20
annual saving.
• LCD also uses less power on power
up.
• LCD use could save energy as less
heat is produced so less need for air
conditioning.
LCD v CRT energy demand
• The uniform brightness of LCD means the
screen can better tolerate variations in
light levels. This means that you need
less lighting in the room where they are
situated and so saves energy.
• A Japanese study showed that replacing
CRTs with new LCDs in 76% of displays
would save 3 billion Kwh of power
(equivalent to i million households or the
power production of about 3 nuclear power
plants).
Electrical items on ‘sleep’ or
‘stand-by’ mode
• The power drawn by modern electronic items in
‘sleep’ or ‘standby’ mode – not fully on and not
fully off – accounts for over 6% of total electricity
consumption in the domestic sector.
• Responsible for the emission of 2.7 million
tonnes a year of the greenhouse gas carbon
dioxide.
• Energy experts have coined a new word to
describe it – lopomos which is shorthand for low
power modes.
• Some of these are useful and some are just
wasted energy.
Electrical items on ‘sleep’ or
‘standby’ mode
• Less useful examples are
unattached mobile phone chargers,
coffee makers, DVD players…..
• Standby costs UK households £25
million per year.
• This figure is growing thanks to the
digital revolution (analogue to digital
converters needed to get a TV
signal, each using as much as 20 W
on stand-by).
• More and more devices will have this
function in the future.
Electrical items on ‘sleep’ or
‘standby’ mode
Electrical items on ‘sleep’ or ‘standby’ mode
• More useful examples are to be found in the workplace.
• In the UK, idle IT equipment is responsible for around
10% of night-time electricity use. This means the
release of 246,000 tonnes of carbon dioxide each year.
• Lopomos account for less than half this. The majority is
equipment left in the full ‘on’ mode (this is because many
machines have their standby function removed). Full on
machines use 74 W compared to 6 W on stand-by.
• If more machines could go into stand-by, it would save a
lot of energy. The greatest saving would be if machines
were turned off altogether.
Electrical items on ‘sleep’ or
‘standby’ mode
•
•
•
•
•
What moves are being made to improve the situation?
Compulsory minimum standards set in Japan (the only
country to do this).
Voluntary agreements with electronics manufacturers in
EU and USA.
Energy Star Scheme specifies maximum standby power
consumption for office equipment sold in EU and USA. A
problem is that it sets undemanding targets and so does
little to increase energy efficiency.
Different models of the same equipment can vary. This
information hard to find.
There is a need for awareness-raising campaigns and
stricter standby performance standards
Energy efficient ratings
• The EU energy rating
label
• The European Union
(EU) energy rating label,
now found on all white
goods, tells you the
appliances exact energy
consumption (kWh) and
its energy efficiency
rating. The EU energy
label rates products from
A++, (the most efficient)
to G (the least efficient).
Energy efficient ratings
• Energy efficiency rating labels are now on household
appliances and electronics to help you compare the
efficiency of products before you buy.
• An energy efficiency rating and energy consumption
figure must, by law, be shown on all fridges, freezers,
fridge/freezers, washing machines, tumble dryers,
washer dryers, dishwashers, electric ovens and light
bulb packaging in the UK. A more energy efficient
product will help you cut down your energy usage, and
therefore reduce your gas and electricity bills.
Key Question 3.4
Can a Sustainable energy supply be
maintained in the future?
• Draw together above points (from Key
Questions 3.1, 3.2, and 3.3) to critically
assess attitudes towards the sustainability
of energy supplies.
Sweden
Sweden
• Since the oil crisis of the early 1970s, Sweden
has invested heavily in the search for alternative
energy sources, and are trying to phase out oil.
• In 1970, oil accounted for over 75% of Swedish
energy supply. In 2006, it was 32%. This is
mainly due to the decline in the use of
residential heating oil.
• 43% of the energy supply comes from
renewable energy.
• Many measures introduced are due to the
Renewable Energy Directive and the Kyoto
Protocol.
Sweden
• The Swedish government wanted to promote
“efficient and sustainable energy use and a cost
effective energy supply” that would “facilitate the
transition to ac ecologically sustainable society”
Power consumption and emissions
• Sweden consumes a lot of electricity per capita
(17,000 kWh per person per year).
• Only Iceland, Norway and Canada consume
more electricity per capita.
Sweden
• However, Swedish carbon emissions are
small in relation to other countries – 5.8
tons of carbon dioxide per year compared
to EU average of 8.6 tons and US average
of 19.7 tons.
• The reason for this is that about 90% of
electricity comes from nuclear or
hydroelectric power. The remaining 10%
comes mainly from biofuels [cogeneration
or CHP (combined heat and power)
plants].
Sweden
Renewable electricity
• Green certificates were introduced in 2003 to encourage
the use of renewable energy. Power consumers have to
buy a certain number of green certificates through their
electricity bills. Power producers receive a certificate for
every megawatt-hour (MWh) of renewable energy they
create. The goal is to boost renewable energy by 17
TWh (terawatt-hour) from 2002 – 2016. Wind power was
further subsidized by means of a tax deduction system
which ran until 2009.
• Installed capacity of wind power has trebled over the last
10 years. The largest wind power park in northern
Europe opened in the Öresund Sound in 2007. It has 48
turbines generating 110 MWh (enough for 60,000
households.
Sweden
Alternative fuels
• Sweden puts a lot of effort into developing renewable,
alternative fuels. Ethanol research began in the 1980s
and Sweden is among the world leaders. Most of the
ethanol sold is produced from grain (although ethanol
produced from sugarcane is better with regard to its
contribution to climate change). Swedish researchers
are focusing on the production of ethanol from cellulose
(referred to as second generation biofuels). This is a
more effective method than grain based production and
does not affect food crops. Other biofuel is biogas that
can be extracted from such things as manure and waste.
Sweden
• The EU want 7.75% of all fuel to come from
renewable energy sources. By 2010. Sweden
had reached 3.1% by 2006., mainly due to
increased use of ethanol. A “pump law” was
introduced in 2006 where all filling stations
selling more than 3.000 cubic metres of gas or
diesel per year are required to supply at least
one kind of renewable fuel.
• Hybrid cars (battery power and fuel) are up and
coming. The next step is plug- in hybrids (cars
with larger batteries charged from the power
grid).
Sweden
Industry
• In 2005, Sweden introduced a special
programme designed to boost energy efficiency
in industry. Around 180 power intensive
industries are taking part and they are granted
tax relief in exchange for drawing up plans and
taking steps to reduce energy use. This
programme has so far resulted in a saving of
about 1TWh (worth around £40 million).
Sweden
Housing
• The government wants a 20% reduction in
energy use in building stock by 2020 (compared
with 1995). Therefore there is a need for energy
efficient housing.
• Passive houses are an example. They are built
without conventional heating systems and are
kept warm by the heat given off by their
occupants. They have extra thick insulation and
intelligent ventilation systems.
Sweden
Housing
• Since January 1st 2008, a new law has been in
force promoting more efficient energy use. It is
based on a EU directive and applies to owners
of private homes, apartment blocks and other
premises.
• The government is investing heavily in
information and advice for households on how to
save energy e.g. changing windows, using lowenergy light bulbs etc.
• Each municipality has an energy advisor
Sweden
Combating climate change internationally
• Sweden is overseeing projects in China,
Brazil, India and the Baltic that use
Swedish technology to reduce carbon
emissions
Iceland
• It is the size of England but has a
population of around 284 000
(England = 51 000 000).
• 72% of energy comes from
geothermal and hydro power (the
remaining 28% from oil imports).
• It uses these resources because
they are available and Iceland
has no fossil fuels or large areas
of trees to cut down.
• Because Iceland is just below the
Arctic Circle, it has long winter
nights and therefore high energy
demand in winter (for heating and
artificial lighting).
Iceland
Hydroelectric power
• Cold water that melts from glaciers in
summer is held behind dams. This
water is then used to generate
hydroelectricity.
• Most water is available in summer
but more energy is needed in winter.
This means that dams (and lakes)
must be large enough to store water
from one summer to the next.
• The silt in the meltwater can fill up
dams and damage turbine blades.
• Hydroelectricity provides 83% of
Iceland's electricity and there is the
potential to produce four times as
much.
Iceland
Geothermal power
• It lies where the North American and
Eurasian plates separate.
• As ground or sea water percolates into
the ground, it becomes super-heated and
provides hot water.
• Electricity can be generated from the
steam, houses and roads can be heated
by the hot water and it can supply thermal
baths.
• Geothermal provides the 17% of
electricity not fulfilled by hydro power.
There is potentially 14 times more energy
available from this source.
Iceland
Can Iceland become a fossil fuel free country?
• The only major fossil fuel use in Iceland is petrol
or diesel for cars.
• It is experimenting with the production of
hydrogen powered vehicles. It is a non-polluting
fuel but power is needed in order to produce the
hydrogen in the first place (by splitting it from
water). Iceland has enough power to be able to
do this.