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Cutting carbon:
Energy
Energy
In this booklet we provide a summary of
what energy is and how we can reduce
(cut) our carbon emissions by using
energy more efficiently. Join us as we
illustrate that cutting carbon does not have
to be difficult, and that it can in fact lead to
a better and more sustainable life for
humans, and the species that inhabit our
planet with us.
Joining the dots –Coal to Carbon
Many millions of years ago, before there
was any sign of life on Earth, there was no
free oxygen in the atmosphere (i.e. there
was no O2). Roughly 1 billion years ago (1
thousand million years ago) the first life
appeared as a blue-green algae. This
primitive one-celled organism was able to
use light from the sun to photosynthesize,
taking in CO2 molecules and releasing the
first O2 molecules. THE FIRST FREE
OXYGEN was released!
Over the millennia more complex plants
appeared and these continued taking in
CO2 and releasing oxygen. This process
then allowed the atmosphere to become
more oxygen rich and this allowed
animals to evolve.
By the start of the carboniferous era,
about 355 million years ago, there were
3000 parts per million of CO2 (i.e. of one
million molecules in the air, 3000 of
them were CO2) in the atmosphere.
During the carboniferous era (which
lasted 50 million years), many trees,
cycads and ferns grew and died. During
their life they would take in CO2, keep
the carbon to build their bulk and
release the O2. Once the plants died
they would sink into the swamps and
eventually become coal.
They did not rot away as most plants
would today. Over this incredibly long
time, a LOT of carbon was taken in from
the atmosphere and stored under the
ground as coal, oil
Energy 3
and natural gas.
Eventually, at the end of the
carboniferous era, the measurement
of CO2 in the atmosphere was 250
parts per million. This meant that
conditions on Earth were now able to
support a wide range of biodiversity,
or different forms of life, including
humans!
When we burn this coal and oil today
we release the carbon back into the
atmosphere as CO2. This is what is
increasing the amount of CO2 in the
atmosphere. Today our atmosphere
has about 380 parts per million of
CO2 and increasing with dramatic
consequences.
Climate Change
CO2 is one of the major greenhouse
gases in our atmosphere that
contributes to global warming and
the resultant climate change.
Climate change is an issue that has
risen to prominence internationally
and an issue that our government in
South Africa has committed to taking
seriously. Securing ecologically
sustainable development and use of
natural resources, is a right
enshrined in the 1996 South African
Constitution (s24).
Greenhouse Gases
Greenhouse gases are CO2,
methane, water vapour and CFCs.
These gases work to allow heat
from the sun into our atmosphere
but they don’t let the heat escape
back into space.
Some of these gases are naturally
occurring and very necessary to
allow life on Earth. But because of
human activity like burning fossil
fuels which releases millions of
tonnes of CO2 into the air and meat
production, farming and landfills
which release methane, the
concentration of GHGs in our
atmosphere is fast increasing.
That means that even less of the
sun’s heat can escape which is
what is causing Global Warming
and Climate Change.
Energy 5
What is energy?
Energy is simply the ability to do
work. While energy itself is invisible,
we see what it can do all around us
every day. We value energy in forms
such as electricity and petrol
because it provides heat, light and
power, which makes our lives more
comfortable. But all energy comes at
a cost, and energy derived from
burning fossil fuels, apart from being
very damaging to the environment,
will eventually run out as these
sources are non-renewable.
Most energy originates from the sun.
Even the energy that enables our
own bodies to do work, e.g. walking,
thinking, exercising, is based on our
intake of food.
Most energy production and
provision involves the release of
carbon dioxide. CO2 is one of the
major greenhouse gases in our
atmosphere that appears to be
contributing to climate change.
What is non-renewable
energy?
Non-renewable energy is finite
i.e. at some point we will run
out of it. Almost 80% of the
electricity and liquid fuel used
in South Africa is derived from
coal. Coal-fired electricity
generation liberates the carbon
in coal through combustion,
giving off the energy that was
originally sun energy, trapped
by plants … and now we want
to use that energy for our own
purposes.
The South African economy
emits about 450 million tons
of CO2 per year through the
burning of fossil fuels. We
have a per capita carbon
footprint of 9 tons and are
the 12th highest emitter in the
world. It is predicted that South
Africa’s emissions will increase
four-fold by 2050 if we
continue using energy as we
are doing at present.
But while electricity makes our
lives comfortable and
convenient, the price of nonrenewable electricity provision
is steadily increasing as stocks
of coal and oil decrease. We
need to develop renewable
sources of energy to ensure a
sustainable future for all.
Even though the upfront costs
for renewable energy are high,
these costs decrease
significantly in time and emit
almost no carbon into the
atmosphere.
What is renewable energy?
Renewable energy is energy that
comes from limitless renewable
sources like sunlight, wind, water
movement and, to some extent,
biomass. Another non-fossil energy
resource is our waste.
All plants and even bacteria growing
and living on land and in water (e.g.
algae) are biomass and can
contribute to our energy diversity in a
sustainable way.
Humans produce huge amounts of
plant waste (e.g. from agricultural
crops) that can be converted to
energy, this resource also renewable.
In South Africa we put great value on
food and water security given that our
country is at risk of water shortages
in the future. For this reason we do
not make use of biofuels derived
from maize to provide what is
considered by some countries to be
another source of renewable energy.
Renewable energy is abundant,
particularly in South Africa which has
a sunny and windy climate and large
portions of unused land, some of
which could be used to provide
energy from wind and solar plants.
We also have a vast coastline which
could provide
wave energy.
Energy 7
Biomass
All biomass can be used to
generate energy. Firewood
and charcoal are usually used
for cooking and space heating.
Sugarcane, maize and oily
seeds can be transformed into
biofuels.
Biofuels come in different
forms: Ethanol out of
sugarcane, maize and any
other sugary or starchy plant
and fruit, can be blended with
petrol.
There is another form of
biofuel called Bio-Diesel. BioDiesel can replace
conventional Diesel. Finally,
Biogas can replace or
supplement natural gas.
Ideas for saving energy in your home or
school
No-cost options: These options cost nothing – just do it and you
will save money and reduce your Carbon footprint!
• Switch off lights in unoccupied rooms/passages.
• Set the maximum water temperature of your geyser to no more
than 50˚C.
• Take a short shower rather than bath.
• Organise your shower times so that you don’t need to turn your
geyser on more than once a day.
• Fix leaking taps and pipes – it takes energy to pump water to your
house, so the more water you save, the less energy you will use.
• Wash your clothes in cold water, or set your washing machine to
a maximum of 30˚C only. Detergents are so good today that the
result is still satisfactory.
• Hang your clothes outside to dry, don’t use a tumble drier if you
don’t have to.
• Keep your fridge door closed as much as possible – don’t stand
there with the door open!
• Move your fridge away from direct sun. The best place for the
fridge is a cool and shady place.
• Switch off electrical appliances at the wall when not in use. Don’t
leave them in stand-by mode. This includes computers, printers,
monitors, radios, TVs, DVD players, video machines, cell phone
chargers, etc.). Over 1% of the total world’s energy consumption
is used in having these types of machines on standby!
• Put only as much water in your kettle as you plan to use, if you
are having one cup of tea, only boil one cup of water!
• Only use your heater when it’s really
necessary, put on a jersey and warm socks
Energy 9
instead.
• Reduce the setting on your air conditioner or space heater (a
1˚C change reduces energy consumption by 6%).
• Check that doors and windows close properly to retain warmth
and prevent cold drafts.
• Walk or cycle more often instead of going by car.
• Use public transport rather than a private car, or start a lift club
with your friends to get to school and back!
• Take your own shopping bag to the supermarket with you.
Low cost options:
• Replace incandescent (old) light bulbs with (energy efficient)
CFLs or LEDs, especially in rooms/areas where the lights are
usually on for many hours a day.
• Cover your geyser with a geyser blanket and all accessible hot
water pipes with insulation.
• Fit your geyser with a timer in order to heat water only when
you need it.
• Fit movement sensors in corridors/low traffic areas to switch off
lights automatically when nobody is around.
• Replace taps and shower heads with aerator heads – this
saves water and energy.
• Buy rechargeable batteries instead of ordinary ones. It takes
50 times more energy to make a battery than it delivers to your
appliance.
• When shopping, opt for the least packaged, local, organic and
seasonal food rather than food that has been shipped or flown in
from far away.
• Try to eat more vegetarian meals as meat production is a big
source of greenhouse gas emissions.
• Convince your family to take local holidays and drive rather
than take long-haul flights. We have a beautiful country with lots
to explore!
waste
Medium to high cost options:
• Install a solar water heater. Conventional geysers use about 40% of
household energy.
• Install solar cells or a small wind turbine to power your pool pump.
• Change your electric stove to a gas cooker: saves lots of energy.
Activity 2: How much electricity do you use in a day?
NB. You need to know how long each item is used for in order to work
out energy consumption.
List the items
you use
during a day
that rely on
electricity
Insert the Watt rating of these
appliances. (Underneath each
appliance - this is an
indication of how much
POWER the appliance is
using)
Number of
hours this
appliance
is used per
day
Calculate the energy in
kWh consumed by this
appliance per day:
Rating in Watt x No. of
hours per day / 1000
Lights
Desktop
computer
Laptop
Heater
Kettle
Fan
Airconditioning
Stove
Fridge
Freezer
T.V.
Playstation
Other
TOTAL:
Multiply the total by the number of days in a month to find out your
monthly electricity consumption. How can you help your school or
family to reduce its electricity consumption – save money, and reduce
your carbon footprint?
Activity 3: Investigate electricity
use in your home and school
A Watt is a unit of
electric power and
when combined with
time, measures
electric energy as a
Wh (Watt hour).
A kWh (kiloWatt-hour)
is 1000 W per hour.
This is the unit used
by ESKOM to charge
their customers.
A Watt rating is the
rating given to all
appliances indicating
the amount of power
they draw.
Some appliances that
use transformers
might not give you a
Watt rating, but will
give information about
the voltage (the
electrical potential in
Volts) and current (in
Amperes). You can
work out the Watt
rating using the
following equation:
1Watt = 1 Volt × 1
Ampere.
1. How much electricity (in kWh) does
your family or school use in one month?
You can find this out by looking at
monthly electricity accounts. Then use
our carbon calculator to work out what
your household or school’s carbon
footprint is for energy use and insert the
figure(s) here:
Household: __________
School: __________
2. How much do you pay per kWh of
electricity? __________________
3. Does your family or school talk about
saving electricity? __________________
4. Does your family or school talk about
alternative energy sources such as solar,
wind, biogas or biofuel energy?
__________________
5. Does your family or school use any of
the above alternative energy sources?
__________________
5a. If Yes, which ones?
__________________
5b. If No, what can you do
about this?
__________________
The concentration of
CO2 in our atmosphere
Scientists around the world agree
that for a healthy planet we need a
CO2 concentration not exceeding
350 parts per million (ppm) of CO2
equivalent.
Today our atmosphere already
contains about 389 ppm of CO2
equivalent and that number is
steadily increasing. At our current
rate of non-renewable energy use
we are heading for an atmospheric
concentration of about 700 ppm by
2050.
This is DOUBLE the safe level of
350 ppm. What impacts do you think
this level of greenhouse gases in
the atmosphere will have on Earth?
Energy 13
Energy 15
This booklet has been printed on Triple Green, an
environmentally friendly paper produced in South
Africa. The fibre composition of Triple Green
includes on average 60% sugar cane. This fibre
(Bagasse) is the remaining fibre after sugar has
been extracted from the harvest cane.