A practical guide to energy
management and electricity
auditing
Activities for energy audits for home and
school
Energy conservation ideas
Demand Side Management
written by Avril Wilkinson, WESSA
design & layout by Michelle Preen,
CONTENTS
Introduction: Background reading material on
energy related issues ........................................2
DSM [Demand Side Management] ..........................3
Sub-organiser for this module ..............................4
How to plan an electricity project [Teacher’s notes
for the project] ..............................................5
Electricity audit [The preliminary audit] .................8
Electricity audit Part 1.....................................15
Electricity audit [Introducing kWh] ......................22
Electricity audit [The electricity meter] ................24
Electricity audit Part 2.....................................27
Electricity audit [Let’s take action—1] ..................30
Electricity audit [Let’s take action—2] ..................33
Energy conservation ideas [Working with natural
processes] ....................................................37
Energy conservation ideas [Landscaping for energy
efficiency] ...................................................40
Energy conservation ideas [Everyday energy-saving
ideas]
44
Extended teaching strategies ............................ 46
This publication was made possible with funding from the DSM section of ESKOM
Introduction
The objective of this education resource is for learners to develop an awareness of how
electricity is used at
home
and at school.
We use electricity every day of our lives, but rarely do we stop to consider how much
we use. To decide if we are using our electricity wisely or not, we must
understand where we use it and how much we actually use. Electricity is measured
and sold just like any other product. You pay for what you use.
Once the learners have reached an understanding of electrical auditing, the booklet
then focuses on providing learners with an understanding on the greenhouse effect.
Global warming is a term which many learners have heard, but most likely do not
understand. This is not surprising, given that there is a great deal of uncertainty among
scientists about global warming. Some scientists are very worried by a recent increase
in average annual temperatures around the world. They are afraid that this warming
trend will severely alter climates here on the planet Earth. These scientists believe that
this warming trend is largely the result of human activities. Other scientists believe that
the evidence is weak for a variety of reasons. The temperature on Earth has greatly
fluctuated for millions of years. The observed increase in temperature may just be part
of this natural fluctuation and have little tie to human activities. This would mean there
would be very little, if anything, that could be done to stop the temperature changes.
This uncertainty among the scientific community forces each person to make their own
judgments about what may be happening to our environment. Learners need to ask
themselves: Is it better to continue emitting large amounts of CO 2 and other harmful
gases into the environment, hoping that global warming will not really occur, or, would
it be safer to take steps to reduce the production of harmful gases, hoping that the
temperature changes can be curbed?
Lastly, the booklet addresses some ways of reducing our
consumption of electricity by becoming good environmental
stewards. It looks at energy management from a perspective
of using the natural climatic processes to our best advantage.
Using the auditing process in the first chapters of the book,
will enable learners to make informed decisions about how
they will react to the global warming crisis.
2
DSM [DEMAND SIDE MANAGEMENT]
Electricity demand is the amount of electricity required by all electric equipment
operating at one time in a building, an area, or a city. It is more expensive, and difficult,
for an electricity service provider, to provide a large amount of electricity for a short
time.
Providing constant, smaller amounts of electricity at off-peak times is called demand
side management. One way to obtain this is to manage electricity use so that all
equipment is never operating at the same time and at the peak demand times.
If we manage our electrical consumption in this way, we make the demand more
consistent, and consequently, electricity suppliers are more able to meet the requirements
of all its consumers. At the same time, we benefit because our use of electricity is
managed, resulting from significant savings in electricity together with the associated
cost.
3
SUB-ORGANIZER
MODULE
FOR THIS
Prescribed Learning Outcomes
It is expected that learners will:
relate energy systems to corresponding natural resources in their home and school
environment.
identify the environmental and societal impacts of a specific source of energy.
describe the interactions between society, technology, and use of electricity.
identify strategies for saving electricity as a result of society's concern for dwindling
non-renewable energy resources.
identify the organizations (and their roles) for supplying electricity in South Africa.
identify alternative energy sources in South Africa and the potential impact of
their use.
Suggested Assessment Strategies
Assess learner’s electricity audit charts for accuracy, and thoroughness.
Assess learner’s strategies for electricity reduction for realistic goals, planning
details, means of tracking success, and outcomes.
Assess learner’s activities for technological detail (accuracy, materials, function,
creative design, durability).
Assess learner’s audits using a predetermined rating scale (grammar, organization,
citations, accuracy, number of details, etc.).
4
HOW TO PLAN AN ELECTRICITY
PROJECT [TEACHER’S NOTES FOR
THE PROJECT]
Doing a good project with your learners will involve many elements to your teaching,
and the following information will assist you in preparing the project in order to include
all the necessary elements.
Step
Step
Step
Step
Step
Step
I— State the Problem
2 - Research, and Hypothesize or Predict
3 - Plan Exercise and Gather Data
4 - Analyze the Data and Make a Conclusion
5 - Take Action
6 - Assessment
More information about Step 1
Begin by stating the project problem: How does human energy consumption affect the
environment, and how can we cut down the amount of energy we use? Ask learners what
they think the answers to these questions are before they begin research. You may want
to record and post their answers in the classroom so that they can see how their
knowledge base changes by the end of the project.
Develop a survey
Since this project involves either the local school area or their homes, learners should
begin by finding out how much the people within this community know already. This
information will be useful to consider when learners design their energy-saving tips in
step 5. Learner groups should begin by conducting an energy opinion survey of their
peers, school staff, and parents or guardians. The following questions are perhaps some
that might be asked:
Do learners/school staff/parents/guardians think they use a lot of energy?
Do they feel that using energy hurts the environment?
What environmentally-friendly energy resources do they know of?
Would they change their behavior to conserve energy?
As an alternative, learners can develop their own survey questions using the following
process: determine what, exactly, learners want to find out; design questions that will
5
get appropriate results; administer a test survey to a small sampling of people; analyze
the results to see if the questions were on target; revise the questions if necessary;
then conduct the survey on a wider scale.
More information about Step
2
Research
Now learners should begin to find the answers to the following questions by asking
questions, or by going to the library to look up information. You may want to divide
groups up so that they investigate these questions for a different kind of energy. Talk
to representatives from the local electrical service provider (usually a municipality or
Eskom) to find out as many ways as you can to save energy in your home and/or school.
Energy type research questions
What are the different kinds of energy used in South Africa?
How are they used?
What impact do the various kinds of energy have on the environment when used?
Energy usage and environmental impact research questions
How much pollution is caused by South African energy use?
Why do we consume so much energy?
What is the history of energy consumption in South Africa — how has it grown, and
why?
How much energy do typical households and schools use?
How can you find out how much energy you use? How can you reduce the amount
of energy that you use?
What are the costs involved with reducing energy use?
Why hasn’t it been reduced in the past?
What are the economic or political factors that may impact energy conservation?
In the end the class can share their findings, and compile their data into an energy usage
matrix on a chart for the classroom.
Forming the hypothesis
Using the research findings, have the class predict which elements are the biggest energy
wasters in the school/home, suggest what changes should be made within the school/home,
and predict how much energy and money these changes would save within the school/home
itself. Finally, ask learners to hypothesize how much this would impact their local
environment. Have learners record their predictions, on another chart labeled "Predictions".
At the end of the project, after learners have conducted their energy audits and
encouraged their school community to make energy-saving measures, they will record
their results in a column labeled "Results" in the same chart.
6
More information about Step 3
Conduct an energy audit following the directions from this booklet on pages 8 - 29. As
you conduct your audit, different groups of learners can be responsible for looking into
energy usage in various areas. Observations should be made daily and recorded in a lab
book in order to keep the data organized. You should review how each group should
record the different kinds of data before the audit begins.
More information about Step 4
Analyze the results of your energy audit. What were the most common areas of energy
waste? Do your results show trends that might be important for other schools and homes
in your area? If all the schools and homes in your area reduced their energy waste, how
might this impact your local environment? Have each group of students write a report
explaining the causes they found for energy waste, and what can be done to solve the
problems. Learners need to consider the financial and behavioral aspects in coming up
with solutions. You may want to ask an expert from the electrical service provider/Eskom
for feedback on your findings.
More information on Step 5
When you finish your energy audit, put as many of your energy efficiency ideas into
practice as you can. Many of these ideas are suggested from page 30 of this booklet.
Keep a record of how much energy you save! Work as a class to write a tip sheet with
your top 15 tips for easy and low-cost ways to save energy at home. Make sure learners
use the information they gathered in the survey in step 1 about how much their intended
audience knows about the topic, and what their attitudes are. They should gear their
tip writing accordingly. Publish the tip sheet in your school magazine, and invite
community members to visit the school for an open day by creating and passing out
flyers to your community. Once action has been taken, have learner groups monitor how
much energy was saved as a result of their actions. Record their findings in the "Results"
column of their charts created in step 2.
More information on Step 6
Have learners write an article documenting the steps they took in this project. They
should add a section reflecting on why energy saving strategies they devised were
effective or ineffective. They should note what strategies worked, or where they went
wrong, and how they would correct these ineffective strategies if they repeated the
exercise. The article should include information from the chart and log books, and any
feedback they got from experts in the field. Also, learners should include their reflections
on what it was like to undertake this project.
Once completed and edited, notify your local newspaper to raise awareness about the
project in your community by sending them your reports.
7
ELECTRICITY AUDIT
[THE PRELIMINARY AUDIT]
Learning outcomes
How did your learners benefit from this exercise?
Knowledge:
Skills:
Attitudes:
i
Information
We spend most of our time in buildings — homes, schools, offices and
stores. But most people seldom notice details about the buildings, such as
how they are designed, how they are built, and how well they are maintained.
These details are important because they contribute to our comfort and
well being and affect the cost of operating them. An "energy efficient"
building is more comfortable than an energy wasteful building. It needs
less fuel or electricity for heating or cooling. A building that is badly
designed and poorly maintained wastes money. Why? Because it is trying
to heat or air-condition the outdoors as well as the indoors. The following
activity allows one to become an instant energy auditor.
Activity
Photocopy the following questionnaire and ask your learners to fill it
in at home together with their parents. Place a tick next to the correct
answer under HOME. Leave the CLASS boxes blank for you to do with
your learners after they have completed the home survey.
8
IS MY HOME AND SCHOOL
ENERGY EFFICIENT?
Name of person doing audit:
Address:
Number of occupants in the house:__________________________________
List rooms in house:
Bedrooms_____
Passage_____
Lounges_____
Porch/verandah_____
Dining_____
Kitchen_____
Bathrooms_____
Pantry_____
Garage_____
Other_____
Number of rooms where there is electricity:___________________________
1
Which of the following would best describe the outside area immediately surrounding
your home?
My Home
My School
( _ ) protected by buildings on sides
( _ ) protected by buildings on sides
( _ ) protected from wind
( _ ) protected from wind
( _ ) faces north
( _ ) faces north
Recommendation:
9
2
Which of the following would best describe the type of insulation in the ceiling
or attic in your home?
My Home
(
) type of insulation
( _ ) none
My School
(
) type of insulation
( _ ) none
Recommendation:
3
What type of floor covering is in your home?
My Home
My School
Carpets ___ Tiles ___
Carpets ___ Tiles ___
Wood ___ Other ___
Wood ___ Other ___
Recommendation:
4
Does your home have cover at the doors and windows against cold (nor large gaps
under doors or broken windows etc.), and/or curtains at windows against heat?
My Home
Against cold?
Against cold?
Against heat?
Against heat?
Recommendation:
10
My School
5
What is the average temperature in your home?
My Home
My School
(
degrees Centigrade)
day - summer
(
degrees Centigrade)
day - summer
(
degrees Centigrade)
day - winter
(
degrees Centigrade)
day - winter
Recommendation:
6
Does your home have fluorescent lighting or CFLs?
My Home
My School
( _ ) yes _____%
( _ ) yes _____%
If yes, where?
If yes, where?
( _ ) no
( _ ) no
Recommendation:
7
Does your home have windows facing north and south? Count all the windows, and
then work out your percentage. Remember to take the size of the windows in
relation to the wall into account.
My Home
My School
Count your windows:
Count your windows:
N (___) S (___) E (___) W (___)
N (___) S (___) E (___) W (___)
N _____%
N _____%
S _____%
S _____%
Recommendation:
11
8
Does your home have ceiling fans? If you do, how many?
My Home
My School
( _ ) yes, how many?
( _ ) yes, how many?
( _ ) no
( _ ) no
Recommendation:
9
Do you turn the lights off when you leave your room?
My Home
My School
( _ ) yes
( _ ) yes
( _ ) no
( _ ) no
( _ ) sometimes
( _ ) sometimes
Recommendation:
10
What is the temperature setting on the hot water tank? To estimate this, ask
yourself if the water from your geyser is scalding hot, or whether it requires an
even mix of hot and cold water to take a bath, or whether you need only a little
cold water for your bath.
My Home
( _ ) 55 – 60 °C low
( _ ) 55 – 60 °C low
( _ ) 60 - 65°C med
( _ ) 60 - 65°C med
( _ ) 65 - 70°C high
( _ ) 65 - 70°C high
Recommendation:
12
My School
Once the audit is complete, return the audit form to your teacher so that the class may
compare results. You may want to draw up a graph showing your results. Discuss the
findings and make recommendations for each question. The audit should be returned
to your parents, and you should explain recommendations.
Together with your teacher and the whole class, now do the audit at your school. Prepare
a talk to your principal and governing body on your recommendations for better energy
management.
13
To be completed only by the teacher or group leader when all the results of the survey
have been completed.
The following matrix is designed to assist you to evaluate your survey and to highlight
troublesome areas in your group of homes as well as to make recommendations for each
participating home.
Home 1
Home 2
Home 3
Home 4
Home 5, 6, 7, etc.
(As many columns as
there are homes)
Occupants in house?
No. of rooms in
house?
1. Outside area
2. Insulation
3. Floor covering
4. Protection from
heat
4. Protection from
cold
5. Ave temp summer
5. Ave temp winter
6. Fluorescent
lights
7. % N facing
windows
7. % S facing
windows
8. Ceiling fans
9. turn off lights?
10. hot water
setting
Circle all the high results with red. What have you discovered? Are our homes and school
energy efficient?
14
ELECTRICITY AUDIT PART 1
Learning outcomes
How did your learners benefit from this exercise?
Knowledge:
Skills:
Attitudes:
i
Information
We use electricity every day, and an energy audit will tell us how much we
use. This activity will also help identify what items in your learner’s homes
use electricity, how often they are used, and how much electricity they
consume. Part 1 is designed to be used in three sections, or mini assignments,
and learners are requested to take charts to fill out at home. Based on the
information that is returned, your learners will be able to begin to very
accurately audit their electrical consumption.
Activity
Section 1. On the first chart, make a list of electric appliances found
in your home. Place a tick in the rooms where you use the items (items
may be found in more than one room).
15
HOME OF:
ADDRESS:
Do you have it?
Appliance
Yes
No
Where is the appliance situated?
Kit. Bed. Bath. Lounge Dining Other If no, what
do you use
instead?
Stove
Kettle
Fridge
Freezer
Geyser
Microwave
Hifi
Radio
TV
Video
Foodwarmer
Heater
Iron
Other________
Other________
Other________
Other________
Other________
Other________
kitchen beds baths lounges dining outside passage garage store other
Lightbulbs –
how many
light fittings
and lamps?
Once the chart has been completed, prepare a time of group discussion based on the
information that your learners have collected.
16
You may want to ask the following questions:
In the home, what area uses the most electricity? Why?
Answer: Kitchen.
The kitchen contains many large electric appliances - fridge (on all the time) and
stove (not on all the time but generates heat which results in high consumption).
The kitchen also contains many other electric appliances - toaster,
microwave, blender, food processor, electric fry pan, etc.
In the home, what areas use the least electricity? Why?
Answer: Home entertainment equipment does not need a lot of electricity to
operate. Also, these appliances are not on all the time.
Section 2. The following chart can be completed by your learners as a second
homework assignment. We have already found out that the kitchen uses the most
electricity, but we now will discover how much time we use an electrical appliance
for. To do this, you will have to decide on a special ―audit day‖. This will give your
group a very accurate assessment of electrical consumption in their homes. In order
to get maximum benefit from the exercise, you may want to involve parents as well.
Audit Preparation for your audit day
The following section is the most important part of all the audits that you will be doing
and will need much preparation. This will greatly assist in the smooth running of your
audit day, and will also make your results very accurate.
1. Refer to your list that you completed in section 1. You will have to make a small
chart for EVERY electrical appliance, and EVERY light fitting that you have in your
home, and you will have to stick each chart next to each appliance. It is also a
good idea to get a number of pencils and cut them up into smaller pieces so that
you have enough for each chart. Alternatively, you could suggest that each family
member wear a ―pen necklace‖ around their necks for the entire day. This way,
there will always be a pen handy when they use an electrical appliance.
2. Some of the appliances will need advance preparation to make your audit day
easier, and more accurate.
17
Kettle: before audit day, boil a half-full kettle and time how long it takes. If it
takes 2 minutes and 50 seconds, then we can work in units instead of time. The
chart for the kettle will therefore look like this:
KETTLE: (half full = 2min 50 sec)
Quarter-full:
Half-full:
Three-quarter full:
Full:
Total time used:
Each time that the kettle is used, tick the appropriate line, and at the end of the day
you will easily work out how much time the kettle was used.
Lights: Go through all the light bulbs in the house and find out what their watt rating
is. You will need this information later, and it is best to get it now. On each chart for
the lights write this watt rating down, and stick your light charts next to the light switch.
Remember to place a chart next to the table lamps as well.
Your light/lamp chart will therefore look like this:
Light bulbs (60watt/ 100 watt/ fluorescent bulb/ fluorescent light 1 bar/
fluorescent light 2 bar/ other). Circle which one it is.
Time
Time
Time
Time
Time
Time
on:
off:
on:
off:
on:
off:
Total time for this light:
Your charts for the video, foodwarmer, heater, iron and fans can also look like this, but
omit the watt rating section.
18
The Stove chart will look like this:
Stove:
Small back plate: time taken:
Large back plate: time taken
Small front plate: time taken:
Large front plate: time taken:
Oven: time taken:
Warming drawer: time taken:
Lastly, some of your charts like the microwave, washing machine, and any appliance
which has its own timer will look like this:
Microwave/ Washing machine/ other
On:
(write how long you have set it for)
On:
On:
On:
Total time taken:
Geyser: record at the end of the day how many baths and showers were taken, and
how many times the sink was filled for dishwashing.
Fridge and freezer: Consult your owner’s manual to find out what the on/off cycle is,
and the watt rating is for your model. Often a phone call to the manufacturer will give
you this information.
Lastly, place a general chart in a visible spot for all the appliances that you would use
only for a brief time, and then store away, such as a vacuum cleaner.
3. Very important: KEEP ALL YOUR CHARTS. You will need them later.
4. Good luck on audit day – try to keep the exercise fun!!! even though it can be very
involved. And remember to discuss the audit requirements with the whole family so
that all members of your household understand what is required.
19
Activity
- Audit Day
Over the weekend (Saturday or the Sunday) record the length of time
that electrical appliances are used in your home during a 24-hour period,
using the method that was explained in the preceeding pages. After
audit day, tally up your times and complete the following table. Staple
all your small charts to the back of this form for safe keeping.
Electrical Appliance
Stove
Kettle
Fridge
Freezer
Geyser
Microwave
Hifi
Radio
TV
Video
Foodwarmer
Heater
Iron
Other________
Other________
Other________
Other________
Other________
Other________
Light bulbs 60W each
Light bulbs 100W each
Light bulbs 120W
Light bulbs 40W
20
Time used in 1 day (24 hours). This amount
will be worked out from all the paper slips
collected from audit day.
Some questions that could be asked now are:
According to your chart, which appliances are used the least amount of time? Why?
Answer: Learner’s answers will vary, but some of the answers will be the toaster,
the kettle, the iron.
We use these appliances only for part of the time
Which appliances do you think use the most electricity? Why?
Answer: Fridge. Freezer and oven.
The fridge and freezer are appliances that stay on all the time.
The oven is an appliance that uses lots of electricity because it must generate
heat.
Activity
Section 3. Processing the information into graph form.
Let us see if these answers show in a graph. With the information that
your learners have collected, we can now draw up a graph that shows
us the percentage of electricity each day (horizontal axis) is used in
each area of our homes (vertical axis). In order to compile this graph,
you will need to do some mathematical work to get the percentages.
TIME
50—60%
40—50%
30—40%
20—30%
10—20%
0—10%
APPLIANCE
Home enter- Laundry Bedroom and Heating and Lighting
Kitchen
tainment
Bathrooms
Cooling
Appliances
You are well on the way to becoming excellent Enegy Auditors! Let us learn further
about kilowatt hours so that we can do an even more accurate audit!
21
ELECTRICITY AUDIT
[INTRODUCING kWh]
Learning outcomes
How did your learners benefit from this exercise?
Knowledge:
Skills:
Attitudes:
i
Information
In the previous energy audit, your learners were able to get some basic
idea of the electrical consumption in their homes, and in which areas of
the home the electricity was most used.
It introduced the concept that each electrical appliance used
varying amounts of electricity, and in the next audit, your learners will
be able to very accurately determine the electrical consumption in
their homes by the introduction of the watt rating of each appliance,
and using this in their calculations in order to obtain the kilowatthour
(kWh) consumption
of each appliance.
We have already collected half of the information required to do this in
the previous exercise — that is, the time that each appliance is used. By
now adding the watt rating, your learners will be able to calculate their
electrical consumption very accurately.
Let us discover how!
22
What is a watt (W)?
Answer: A watt is a unit of power and each appliance is marked with its watt
rating. For instance, if you look carefully at a light bulb you will see 60W or 100W
printed on the bulb. This is its watt rating. Look at other appliances to find the
watt rating.
What is a Kilowatt (kW)?
Answer: A kilowatt is a thousand watts . To calculate kW from W, divide the
W rating by 1000 : kW = W ÷ 1000.
What is a KilowattHour (kWh)?
Answer: kWh is the term used to calculate electrical use. One kWh is one unit
of electricity. Electric companies charge for the number of units that each household
uses.
How do I calculate kWh?
Answer: Multiply the number of kilowatts by the time that the appliance was
used.
For example: If a 100 watt light bulb is left on for 10 hours, one kilowatt hour
(kWh) of electricity is used (100 ÷ 1000 x 10)
Suppose a 100-watt bulb, serving as an outside night light, is left on for eight hours
a night, 365 days a year. This bulb consumes 292 kWh of electricity a year ((365
x 8 x 100) ÷ 1,000 = 292 kWh).
Activity
The formula for calculating kWh is therefore the watt rating divided by
1000 (to get the kW), then multiplied by the time. Can your learners
complete the following table?
Appliance
Watt rating Hours per day Hours per month
Kettle
2000W
2
2 bar heater
1300W
5
Iron
1000W
1
550W
6
Fridge
60 (2x30)
No. of kWh in one month
120kWh (2000÷1000 x 60)
23
ELECTRICITY AUDIT
[THE ELECTRICITY METER]
Learning outcomes
How did your learners benefit from this exercise?
Knowledge:
Skills:
Attitudes:
i
Information
Every home is equipped with an electricity meter. The meter measures the
amount of electricity consumed in a house in units called kilowatthours
(kWh). We are then charged according to the amount of electricity we have
used. Reading our own meter keeps us informed of how much electricity we
are using. If we are trying to reduce energy consumption and costs, we
want to keep track of those kilowatthours!
Activity
Ask your learners to find their electricity box at home. The electricity
meter box may look different in many South African homes, depending
on the age of the house.
Some boxes are locked, and can usually be opened with a special allan
key, or even a pair of long-nosed pliars. If the box cannot be opened
in this way, then they should not force it open, and must not complete
the activities in this chapter.
24
What have you discovered about your electricity meter?
Answer: Generally, the meter will have a 6-digit number—5 numbers in black,
with a red number after as a decimal of the number. For instance, 54100,6 (6 is
in red).
Under the digital reading, they will see a horizontally spinning disc which is
recording the electricity consumption.
Activity
Reading our meter for a week.
Your learners will need five days at home to complete this activity. They
will be taking the actual reading of their own electricity meter.
It may be best to use a full, Monday to Friday week for the activity.
It is important for the learners to get into the habit of reading their
meters. When all the electrical audits have been completed, and electrical
measures have been taken, then this is the way that learners can check
up on themselves to see if the sav ing measures are working.
Remind the learners that they need to take the reading at the same
time each day.
Day of the week
Reading for the day
kWh used
Sunday
Sunday’s reading is
Do not fill in here
Monday
Monday’s reading is
Monday’s reading minus Sunday’s
reading =
Tuesday
Tuesday’s reading is
Tuesday’s reading minus Monday’s
reading =
Wednesday
Wednesday’s reading is
Wednesday’s reading minus Tuesday’s
reading =
Thursday
Thursday’s reading is
Thursday’s reading minus
Wednesday’s reading =
Friday
Friday’s reading is
Fridays reading minus Thursday’s
reading =
25
From the results of your readings:
Work out your average daily kWh. (Add 5 readings and divide by 5)
Record the amount here
Work out your average monthly kWh. (Daily average multiplied by 30)
Record the amount here
Activity
Activities for the school’s electricity meter.
Ask the caretaker if the learners can read the school’s electricity meter
for five days in a row. After you have completed the activity for the
consumption of electricity at school, the learners can compare the
amount of electricity the school uses to the amount they use at home.
Have the learners read the school’s electricity meter at the end of each
month and make a graph for each month. Which months does the school
use the most electricity? The least? Why?
Have the learners collect old electricity accounts for their homes. They
can compare their monthly estimate to the actual amount on the account.
Is their amount about the same as what is listed on the account? In
which months do they use the most electricity? The least? Why?
26
ELECTRICITY AUDIT PART 2
Learning outcomes
How did your learners benefit from this exercise?
Knowledge:
Skills:
Attitudes:
i
Information
Your learners have now reached the stage where they are able to conduct
a full electricity audit. They have learned much over the past lessons and
activities. The full audit will show your learners the energy consumption
in exact amounts, as well as when, and where, the electricity is used.
They have recorded the appliances in their homes, and the time that the
appliances are used, and they have also learned how to calculate the kWh
consumption for each appliance. All that now remains to be done is to
complete the full audit table to ascertain how much electricity each of the
appliances uses.
Once this is done, they are asked to refer to the electricity meter reading
activity to compare that reading with the reading that they have determined
from the table in this activity. The two readings should be very similar.
Activity
It is time to conduct the full electrical audit.
In the following table, the first column was completed in part 1 of the
electricity audit. The other columns were also exercises and activities
in the previous chapters. Some of the watt ratings have been added to
the list, and some you will have to find out by looking it up on the
appliance or in the appliance handbook. You can also make inquiry at
your local Eskom office or at the appliance service center. Also, for
convenience, we have added some in the table at the end of this activity.
27
1. Electrical
Appliance
2. Time (in
minutes) used
in 1 day (24
hours) Use the
information
from activity 2
of audit – part
1
3. Time (in
hours,
expressed as a
decimal). To do
this, divide the
time (in
minutes) in
column 2 by 60
4. Time used
in 1 month.
Multiply the
time in
column 3 by
30.
5. Watt
rating. This is
to be found
on the
appliance, or
in the
appliance
handbook.
Stove front
large plate
2000W
Stove front
small plate
1500W
Stove back
large plate
1500W
Stove back
small plate
1000W
Stove—oven
2000W
Light bulbs
60W each
60W
Light bulbs
100W each
100W
Light bulbs
40W each
40W
Fluorescent
Light bulbs
120W
120W
combined
Light bulbs
Another
wattage
2000W
Kettle
Fridge
12hr
300W
Freezer
12hr
600W
Geyser
3000W
Microwave
1300W
Hifi
100W
Radio
TV
Video
80W
300W
80W
Heater—2 bar
1300W
Iron
1500W
Washing machine
- unheated
800W
Food processor
400W
Fans
Sewing machine
Other________
Other________
Other________
28
55W each
85W
6. Kilowatt
rating.
Divide the
watt rating
by 1000.
kW = W ÷
1000
7. kWh
Multiply the kW
rating in column
6 by the month
time in column
4.
kW rating x time
Now add up all the numbers in the last column (your kWh for 1 month)
To verify your results, go back to the chapter on reading the electricity meter. Your
monthly figure should be similar.
Some other watt ratings that you might need are:
Dishwasher – heater
Dishwasher – motor only
Frying pan
Toaster
Electric beater
Tumble Dryer
2000W
700W
1500W
1100W
200W
300W
Washing machine - heated
Heater (fan type)
Heater (ceramic type)
Vacuum cleaner
Electric blanket
2800W
2000W
1500W
600W
100W
YOUR AUDIT IS COMPLETE! CONGRATULATIONS!
The Ladysmith High School did the audit and some of their totals were as follows:
Home
Home
Home
Home
1
2
3
4
1195.07 (audit total)
636.70 (audit total)
1389.85 (audit total)
871.26 (audit total)
1164 (meter reading total)
609 (meter reading total)
998 (meter reading total)
876 (meter reading total)
Activity
Converting the data into cost per unit.
Remember, each unit of electricity is one kWh of electricity.
Find out what the cost per unit is of the electricity in your area. To do so,
you will have to phone your electricity service provider—either your
municipality or Eskom. You can also get this information from your lights
and water account. In order to get a basic figure, divide your ―charge‖
by your ―consumption‖, and this should be in the region of 30c per unit.
Which are the most expensive appliances to run?
Answer: From your audit results, answers will differ, but they are the appliances
with the highest kWh. For energy saving ideas, learners should concentrate on
these appliances. From the results of the audit, each learner will now be able to
make informed recommendations on electrical saving in their homes. The results
of the audit should be taken home and discussed with parents.
This audit can also be done for your school!
Recently a school in East London, Stirling Primary, conducted an electricity audit at
their school. To interpret their data, they compiled a speadsheet of electrical consumption
showing how much money each appliance cost to run.
They also used the data to draw a bar graph using the appliances on the horizontal axis
and the amount in rands on the vertical axis. Their findings showed that ceiling fans
and lights were the schools highest expenditure for electricity. Why is this different to
an audit at home?
29
ELECTRICITY AUDIT
[LET’S TAKE ACTION - 1]
Learning outcomes
How did your learners benefit from this exercise?
Knowledge:
Skills:
Attitudes:
i
Information
Conducting an energy audit is a good method of showing your learners how
electricity is used in their homes. However, the focus of the teaching
strategy should ultimately be good environmental stewardship. If we can
use less electricity, we will generate less carbon dioxide, and in doing so
we will be contributing to a sustainable environment. In this activity,
learners become familiar with the concept that one of the major sources
of carbon dioxide is the production of electricity. They identify ways in
which they might decrease their contribution to the carbon dioxide in our
atmosphere by decreasing their use of electricity.
Most people believe that air pollution is a problem caused by factories and
cars. This is so, but our excess use of electricity is also a contributing
factor. The largest contributor to excess carbon dioxide in the atmosphere
is from the burning of fossil fuels. We burn fossil fuels directly in our cars,
but the excess carbon dioxide in the atmosphere is also from electricity.
The electricity we use here in South Africa is generated primarily by burning
coal. Every time we use electricity, we are contributing to the greenhouse
gases.
30
Activity
How much CO2 do we put into the atmosphere each day by our use of
electricity?
Your learners have already made a very accurate assessment of the
amount of electricity (in kWh) that they have used, by conducting the
electricity audits in the previous chapters.
Now they can calculate the approximate corresponding amount of carbon
dioxide added to the atmosphere for the amount of electricity that was
used in their home.
For every 1 kWh of electricity that we use, approximately 1.1 kg of
carbon dioxide is released to the atmosphere.
We have already calculated our consumption of electricity for a month
in kWh. All we need to do now is multiply this amount by 1.1 to calculate
how much CO2 we put into the atmosphere.
(kWh x 1.1 = amount in kilograms of CO2. )
Activity
After our calculations in the previous activity, we may be in some shock!
Let us go on an ―energy‖ diet!
If you had to choose 3 appliances to "go without" for 2 weeks
in order to help reduce CO2 emissions, which appliances would
you choose? Explain why you choose these appliances. How
much CO2 do you think that you will save over the 2 week
period?
Ask each student to draw up an Energy Diet Plan for their home.
Get each member of your family to commit to making at least
one change aimed at saving electricity. Be sure to let them
decide what they would like to go without.
9 kilograms of CO2 are emitted into the atmosphere for
approximately every 4 litres of gasoline burned in your family
car. Calculate your CO2 contribution to the atmosphere from
driving or being driven for a typical day. Can you find ways to
also go on a ―petrol‖ diet? Perhaps share with a neighbour or
walk to school…..
31
Energy experts say that the carbon dioxide released per family during the
production of the things we buy and the services we use, is about equal to
the amount of carbon dioxide produced by our direct use of energy. Can we
also go on a ―spending‖ diet? Do we really need that extra T-shirt or that
ice-cream…..
If your family's car was more efficient, a large amount of carbon dioxide
would be prevented from going into the atmosphere. Can we also go on an
―car efficiency‖ diet? Ask your learners to discuss this with their parents to
find ways to get better fuel consumption (per km driven) from our cars.
Make a list of other actions that your family could take to reduce carbon
dioxide emissions.
If your work on this project is to be written up and presented, it might be a good
idea for you to verify your savings by taking your electrical consumption reading
each month from the electricity meter, and/ or proving that your electrical saving
ideas are working by the reduction of electricity from your monthly account.
We are well on the way to becoming good environmental stewards. In this activity we
explored ways to help reduce the carbon dioxide emissions to the atmosphere. In the
following chapter, we look at ways in which we can actively take a role in making our
environment a better place for us all.
32
ELECTRICITY AUDIT
[LET’S TAKE ACTION - 2]
Learning outcomes
How did your learners benefit from this exercise?
Knowledge:
Skills:
Attitudes:
Information
Deciduous trees reduce cooling costs in the summer, but don't block out
the sun's warming rays in the winter. They also absorb carbon dioxide and
prevent it from going to the atmosphere. The process of absorbing CO2 and
releasing oxygen is part of photosynthesis.
Activity
Calculating how much CO2 is absorbed by trees during photosynthesis.
Depending on its size, approximately 10 to 23 kilograms of CO2 per
year is absorbed by a tree. With this information, we can begin to
collect data which will give us the necessary information in order to
take action.
The 10 to 23 kilogram range stated for the amount of CO2 absorbed by
a tree presents an interesting challenge for learners.
Educators may choose simply to use the average of this range, in which
case each tree is counted in the designated area, and the average of
15.5 kg per tree per year is used. (10 + 23 ÷ 2 = 15.5)
However, it might be more beneficial for learners to set up their own
criteria for how to use the numbers. For example, learners may want
33
to measure the circumference of the tree trunk one meter above the ground as their
standard. They could take a trip around their home garden and/ or school ground
to see the variation that exists and then set up a scale by which they assign a
number from 10 to 23 for different circumferences. Learners may wish to estimate
the height
of the trees. For example, if the tree is one story or less in height, they might want
to assign a number close to 10 for its CO2 absorbing ability. This makes for interesting
discussion on the learners part, while requiring them to think about scale. It is
important, however, that a class consensus be reached. If each learner uses a different
scale, it will not be possible to compare and pool results.
As learners are deciding on which areas to assess, you may want to list several small
parks, the school grounds, and other key areas in your community. Most learners,
however, will want to assess their own garden, as this makes the idea of carbon debt
more personal. However, there will be some learners who do not have gardens, or
are unable to assess their gardens. Ask these learners to volunteer to survey the
other areas. This would insure a broad sampling of a variety of areas.
The following table is a sample data table for the activity, if you choose to use your
own set of criteria for calculating CO2 absorption of trees. If you are using the average
of 15.5Kg, then the following table is unnecessary.
Location
Thandi’s
garden
No. of trees
Circumference
of tree
Kg of CO2 assigned Kg of CO2 absorbed
for circumference
by trees
3
> 2 meters
23
23 x 3 = 69 kg
2
< 2 meters
15
15 x 2 = 30 kg
4
<1 meter
10
10 x 4 = 40 kg
139 kg CO2 per yr
Total for
Thandi’s
garden
Jane’s
garden
Total for
Jane’s
garden
5
> 2 meters
23
23 x 5 = 115 kg
6
< 1 meter
10
10 x 6 = 60 kg
175 kg CO2 per yr
Review this with your learners before they begin collecting data so that it is
understood.
Once all the data has been collected and the calculations completed, ask each person
to display their findings on a class poster or on the blackboard. This will allow learners
to determine total CO2 absorption by all the trees surveyed by their classmates.
Once a grand total has been achieved, learners will really get the idea that the trees
in their community do make a difference on helping reduce greenhouse gases.
34
Activity
Balancing the carbon dioxide debt.
In the previous activity, your learners were able to assess how much
carbon dioxide is absorbed in a specific area. Most of the learners will
have chosen their home gardens in which to do this assessment.
This activity deals with planting trees to balance the carbon dioxide
generated by our personal and/ or family use of electricity.
We have already established how much electricity we use in
one month.
We also know that for every I kWh of electricity that we use,
approximately 1.1 kg of carbon dioxide is released to the
atmosphere, therefore we have established how much carbon
dioxide each of our homes places into the atmosphere by our
use of electricity. Remember also to calculate the yearly amount
by multiplying the monthly figure by 12.
We also know that each tree absorbs an average of 15.5 kg per
year of carbon dioxide.
Can your learners work out how many trees they would have to plant
to balance their carbon dioxide debt?
At the end of this activity, it would be interesting to produce a table
showing all the results of all your audits.
At Ladysmith High school, the results were tabulated as follows:
Name Audit
of home result
Avril
Electrical
meter
reading
month
month
871kWh
876kWh
Ave of the
2 monthly
readings
CO2
output
month
874kWh
No. of trees No. of No. of trees
required for trees in needed to
CO2 balance garden
plant
year
961kg 11,532kg
744
36
708
Are you shocked! The group at Ladysmith were!
Because the number of trees required to balance our carbon debt is so
high it is important not to become discouraged. The following activity is
designed to move your project from a very local focus, into the broader
community in order to involve a greater number of people. In this way,
we are becoming good environmental stewards by encouraging others
about environmental responsibility, and at the same time, planting a
greater number of trees than what our gardens can accommodate.
35
Activity
Plant-a-Tree campaign.
By now, your learners will have got the idea that planting trees will
help our environment. They might even have made promises to plant
trees in their gardens and/ or school grounds to balance their carbon
dioxide debt.
It is now time to take this even further!
Challenge the class to draw a street plan of a specific area in
their community where trees could be planted for the benefit
of the whole community. On the map, mark the places where
trees are currently growing, as well as other structural objects.
Draw up a plan designed to increase the number of trees in the
area. As part of the plan, include information on the CO2 absorbing
ability of the proposed trees. Mark the locations of the new
trees on your map. Be sure to consider the importance of shade
on buildings in deciding where to place the trees. (Shade helps
reduce the cooling costs of buildings.)
Design an advertising campaign aimed at getting people to plant
more trees.
Present your campaign in the form of a poster, brochure,
newspaper, or other creative form.
Emphasize and communicate the CO2-absorbing abilities of trees.
Design colorful graphs, charts, and other graphics to help illustrate
the CO2 absorbing abilities of trees.
Be creative! You should also read through the chapter on ―Landscaping
for energy efficiency‖ further on in this book. This will give you some
ideas about how to do this activity.
36
ENERGY
CONSERVATION
IDEAS
[WORKING WITH NATURAL PROCESSES]
Many energy conservation ideas can be put in place merely by understanding nature,
the environment and climatic processes in South Africa.
For instance, we know that hot air rises, and cool air sinks. By using this concept, and
many other elements of the natural environment, we can reduce the temperature of
our homes significantly in Summer, and raise the temperature in Winter.
This is called passive heating and cooling.
In Summer, open all you windows in the evening to allow free passage of cooling
air during the night. In the morning, as soon as the temperature begins to rise,
close up the windows and draw your curtains against the heat. This will keep the
temperature of the house cooler for longer. As the temperature begins to rise later in
the day, open the top windows to allow the hot air to escape. In the evening, open all
your windows again as before.
In Winter, reverse the process to keep the house warm.
Listed below are some natural processes that you can use in passive heating and cooling.
Radiation : This is the passage of energy through open space, like sunlight. In the
winter, during the daytime a building absorbs solar radiation, but after the sun goes
down, it starts to re-radiate heat to the cold outside air unless something is done
to block the radiation. In the summer, efforts have to be made to block solar radiated
heat from entering the house.
Conduction : This is the passage of heat through a material. Some materials, like
glass and metal, conduct heat (and lose it) easily. Insulation helps to block conduction
of heat. If ceilings and walls are poorly insulated, they conduct heat from the house
to the outside. Installing a ―blanket‖ of material (like pink aerolite) in your ceiling
will keep your house cool in Summer and warm in Winter without the exorbitant
electricity costs associated with air conditioners!
Convection: This is the transfer of heat by movement of air. In the winter, as heated
air contacts cold surfaces such as windows, it loses heat. The cooled air is denser
than warm air, so it tends to settle, pushing warm air toward the ceiling. These
temperature changes and air movements form a pattern. Warm, light air from the
ceiling area is chilled along the windows, becomes heavier and drops to the floor.
It moves across the floor, is reheated, moves up the opposite wall (away from the
window), across the ceiling and down past the window again. During each cycle the
air loses heat. Heat must be supplied from a sunny window, a furnace, stove, or
other heater to maintain a comfortable temperature.
37
Air Infiltration: This is the air seepage due to wind. Air pressure pushes hot air (cold
air in the winter) through tiny openings on the windy side and draws cooled air in
on the opposite side of the house. Infiltration occurs through wall cracks, gaps around
paneling (top, bottom, sides), cutouts for pipes and wiring, poor seals for window
sashes, doors with poor weatherstripping, and loose moldings.
Hot Water Waste : Most people waste hot water by following some of the these bad
habits:(1) letting the hot water flow while shaving, (2) using excessive hot water in
taking a bath or shower, (3) using hot water for all loads when washing clothes, (4)
setting the hot water geyser too high, (5) not insulating all the hot water lines and
hot water cylinder, and (6) letting the hot water run while rinsing dishes. Here are
some ways that you can save hot water waste:
1) Turn the hot water control off when not in use, do not let it run for chores like
rinsing dishes, shaving or washing your face.
2) Repair all water leaks.
3) Install a flow control valve on all shower heads.
4) Heat your hot water with gas if available.
5) Install a hot water timer on your water cylinder.
6) Insulate your hot water tank and pipes.
7) Turn water heater off if you leave for more than two days.
55°C - 60°C: The average family can save ten to twenty percent (10-20%) of their
electricity account by setting the thermostat at 55°C in the summer and 60°C in
the winter.
Fluorescent Lights: Up to thirty percent (30%) of lighting costs (80% if CFLs are used)
can be eliminated by using fluorescent instead of incandescent lights. It is now
possible to replace most incandescent light bulbs with fluorescent bulbs.
Windbreak: A dense row of trees, or a fence or other barrier that interrupts and
changes the local path of the wind can also help to keep temperatures stable.
Windbreaks located on the predominately windy side of a building can save heat by
reducing wind chill and air infiltration.
House Orientation: Most energy conservation practices will be made much easier
if the home is properly oriented. A North orientation will make it possible to use
natural light and natural heating and cooling. During Autumn and Spring, it may be
possible to use only natural heating and cooling with windows and doors only on the
long axis of the house (the South and North). It is possible to draw the South and
North breezes for cooling purposes. The sun coming in from the North windows is
beneficial for winter heating.
38
Summary
The most effective low cost energy savers include:
1) Plant trees, grass and shrubs in the desired location.
2) Adjust your thermostat to 55°C in the summer and 60°C in the winter.
3) Change all bulbs to fluorescent or CFLs.
4) Turn all lights off when you leave a room.
5) Install ceiling fans.
6) Lower the thermostat to 120°F on your water heater.
39
ENERGY
CONSERVATION
IDEAS
[LANDSCAPING FOR ENERGY
EFFICIENCY]
This chapter will give you some landscaping tips that will help you
save energy and money year-round, and includes climate and site
considerations, design and planning, and tree and shrub selection.
Are you looking for cost-effective yet eye-pleasing ways to lower your electricity costs?
Planting trees, shrubs, vines, grasses, and hedges could be the answer. In fact, landscaping
may be your best long-term investment for reducing heating and cooling costs, while
also bringing other improvements to your community.
A well-designed landscape will:
Cut your summer and winter electricity costs dramatically.
Protect your home/school from winter wind and summer sun.
Reduce consumption of water, pesticides, and fuel for landscaping and lawn
maintenance.
Help control noise and air pollution.
Summer
You may have noticed the coolness of parks and wooded areas compared to the
temperature of nearby city streets. Shading and evapotranspiration (the process by
which a plant actively moves and releases water vapor) from trees can reduce surrounding
air temperatures as much as 9 degrees F (5 degrees C). Because cool air settles near
the ground, air temperatures directly under trees can be as much as 25 degrees F (14
degrees C) cooler than air temperatures above nearby black rooftops.
Winter
You may be familiar with wind chill. If the outside temperature is 10 degrees F (-12
degrees C) and the wind speed is 32 kilometers per hour, the wind chill is -24 degrees
F (-31 degrees C). Trees, fences, or geographical features can be used as windbreaks
to shield your house from the wind.
Houses with windbreaks placed only on the windward side (the side from which the wind
is coming) can significantly reduce their energy consumption compared to similar but
unprotected homes. If you live in a windy climate, your well-planned landscape can
reduce your winter heating costs.
Landscaping for a Cleaner Environment
Widespread tree planting and indigenous planting offer substantial environmental
benefits. Trees and vegetation control erosion, protect water supplies, provide food,
create habitat for wildlife, and clean the air by absorbing carbon dioxide and releasing
oxygen.
40
Certain grasses, such as buffalo grass and fescue, only grow to a certain height — roughly
15 centimeters — and are water thrifty. By using these species, you can eliminate the
fuel, water, and time consumption associated with lawn mowing, watering, and trimming.
Also, recent studies have found that gasoline-powered mowers and edge trimmers
also contribute to air pollution.
Climate, Site, and Design Considerations
Climate
South Africa can be divided into four approximate climatic regions for easy understanding
of this principal: temperate, hot-arid, hot-humid, and cool. The energy-conserving
landscape strategies you use should depend on which region you live in. These landscaping
strategies are listed by region and in order of importance below.
Temperate
Maximize warming effects of the sun in the winter.
Maximize shade during the summer.
Deflect winter winds away from buildings.
Funnel summer breezes toward the home.
Hot-Arid
Provide shade to cool roofs, walls, and windows.
Hot-Humid
Channel summer breezes toward the home.
Maximize summer shade with trees that still allow penetration of low-angle winter sun.
Avoid locating planting beds close to the home if they require frequent watering.
Cool
Use dense windbreaks to protect the home from cold winter winds.
Allow the winter sun to reach north-facing windows.
Shade north and west windows and walls from the direct summer sun, if summer
overheating is a problem.
Microclimate
The climate immediately surrounding your home is called its microclimate. If your home
is located on a sunny northern slope, it may have a warm microclimate, even if you live
in a cool region. Or, even though you live in a hot-humid region, your home may be
situated in a comfortable microclimate because of abundant shade and dry breezes.
Nearby bodies of water may increase your site's humidity or decrease its air temperature.
Your home's microclimate may be more sunny, shady, windy, calm, rainy, snowy, moist,
or dry than average local conditions. These factors all help determine what plants may
or may not grow in your microclimate.
Siting and Design
A well-oriented and well-designed home admits low-angle winter sun, rejects overhead
summer sun, and minimizes the cooling effect of winter winds. If you are building a
41
home, pay attention to its orientation.
In the southern hemisphere, it is usually best to align the home's long axis in an eastwest direction. The home's longest wall with the most window area should face north
or northeast. The home's south-facing and west-facing walls should have fewer windows
because these walls generally face winter's prevailing winds. South-facing windows
receive little direct sunlight.
If your home is already built, inventory its comfort and energy problems, then use the
following landscaping ideas to help minimize these problems.
Shading
Solar heat passing through windows and being absorbed through the roof is the major
reason for air-conditioner use. Shading is the most cost-effective way to reduce solar
heat gain and cut air-conditioning costs. Using shade effectively requires you to know
the size, shape, and location of the moving shadow that your shading device casts.
Remember that homes in cool regions may never overheat and may not require shading.
Trees can be selected with appropriate sizes, densities, and shapes for almost any
shading application. To block solar heat in the summer but let much of it in during the
winter, use deciduous trees. To provide continuous shade or to block heavy winds, use
evergreen trees or shrubs.
Deciduous trees with high, spreading crowns (i.e., leaves and branches) can be planted
to the north of your home to provide maximum summertime roof shading. Trees with
crowns lower to the ground are more appropriate to the west, where shade is needed
from lower afternoon sun angles. Trees should not be planted on the northern sides of
solar- heated homes in cold climates because the branches of these deciduous trees will
block some winter sun.
Trees, shrubs, and groundcover plants can also shade the ground and pavement
around the home. This reduces heat radiation and cools the air before it reaches your
home's walls and windows. Use a large bush or row of shrubs to shade a patio or
driveway. Plant
a hedge to shade a sidewalk. Build a trellis for climbing vines to shade a patio area.
Vines can shade walls during their first growing season. A lattice or trellis with climbing
vines, or a planter box with trailing vines, shades the home's perimeter while admitting
cooling breezes to the shaded area.
Shrubs planted close to the house will fill in rapidly and begin shading walls and windows
within a few years. However, avoid allowing dense foliage to grow immediately next to
a home where wetness or continual humidity are problems.
Wind Protection
Properly selected and placed landscaping can provide excellent wind protection, which
will reduce heating costs considerably. Furthermore, these benefits will increase as the
trees and shrubs mature. The best windbreaks block wind close to the ground by using
trees and shrubs that have low crowns.
Evergreen trees and shrubs planted in the path of the prevailing winds in your area are
the most common type of windbreak. Trees, bushes, and shrubs are often planted
together to block or impede wind from ground level to the treetops.
A windbreak will reduce wind speed for a distance of as much as 30 times the windbreak's
42
height. But for maximum protection, plant your windbreak at a distance from your home
of two to five times the mature height of the trees.
In addition to more distant windbreaks, planting shrubs, bushes, and vines next to your
house creates dead air spaces that insulate your home in both winter and summer. Plant
so there will be at least 30 centimeters of space between full-grown plants and your
home's wall.
Planning Your Landscape
Before you start landscaping, you must first develop a plan. The components of your
plan could include deciduous trees and plants, coniferous trees and plants, earth berms,
walls, fences, sheds, and garages. This section will help you create a landscape plan
before you plant around your existing home or before you begin construction on a new
house.
Use paper and different-colored pencils to begin designing your landscape. First, sketch
a simple, scaled drawing of your yard. Locate its buildings, walks, driveways, and services
(e.g., sewer, electric, and telephone lines). Note the location of all paved surfaces —
streets, driveways, patios, or sidewalks — near your home. Then identify potential uses
for different areas of your yard: vegetable gardens, flower beds, patios, and play areas.
Draw arrows to show sun angles and prevailing winds for both summer and winter. As
you sketch, circle the areas of your yard needing shade or wind protection.
Indicate with arrows how you want views to be preserved or screened. Mark routes of
noise pollution you wish to block. Also, highlight areas where landscaping height or width
may be restricted, such as under servitude lines or along sidewalks.
Notice yard areas that suffer from poor drainage and standing water. Some trees and
shrubs will not grow well in poorly drained areas; others will. Note existing trees and
shrubs. Plan for their replacement if they are old or sick and if they provide valued
shade or windbreak.
Perhaps you live in an urban area where yards are small and neighbours close. Your
neighbor's yard may be the best place for trees to shade your north-facing windows.
Your yard may be the best location for their windbreak. Bringing your neighbours into
your plans could benefit everyone involved.
The more you identify your goals and familiarize yourself with your yard's features —
current and proposed — the better your chances for success with your landscaping
projects.
Selecting and Planting Trees and Shrubs
Trees and shrubs come in all shapes and sizes. How you select your trees and shrubs and
how you plant them will directly affect your home's comfort and energy efficiency. You
can get information on regionally appropriate species from your local nursery and
landscaping experts.
Trees and shrubs have a life span of many years and can become more attractive and
functional with age. But poor planning of landscape improvements often creates trouble.
Ensure proper plant placement and minimal maintenance before you plant!
Contact your county extension agents, public libraries, local nurseries, landscape
architects, landscape contractors, and local energy offices for additional information
on regionally appropriate plants and their maintenance requirements.
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ENERGY
CONSERVATION
IDEAS
[EVERYDAY ENERGY-SAVING IDEAS]
Energy Management at Home and at
School
Energy management means using electricity more wisely. There are two ways of saving
energy: replacing old equipment with more energy efficient technologies or reducing
the use of the appliance. A Grade 4 to 6 learner is not going to replace expensive
equipment, other than relatively inexpensive items like incandescent light bulbs with
compact fluorescent lights. However, there are many things that learners can do to
use electricity wisely at home and at school.
At School
All artificial light is produced from electricity. Fluorescent lighting requires less electricity
to produce the same amount of light as incandescent lights (common light bulbs).
Fluorescent lighting is very common in schools. Lower wattage fluorescent tubes have
been developed to produce the same amount of light as the standard 40-watt tube.
Many schools are converting to lower wattage tubes and reflectors to increase lighting
efficiency.
Of course, the simplest thing for the learners to do is to shut lights off in rooms that
will be unoccupied even for a few minutes. A common misconception is that leaving
fluorescent lights on is more energy efficient than turning them off because the lights
require a lot of electricity to start up and burn out more quickly when turned on and off
frequently. However, modern fluorescent lights require little electricity to start up. While
being turned on and off does decrease the life of the tube, the value of the saved
electricity is greater than the increased cost of replacing fluorescent tubes. All fluorescent
lights should be shut off if the room will be unoccupied, even for a few minutes.
At Home
The most important message that learners can take home to their families is to shut
off electric appliances when they are not in use. Lights, TV’s, VCR, and other appliances
are often left on accidentally.
Almost one third of all home electricity use is in the kitchen. Learners can do a number
of things to reduce electricity use in the kitchen. In our climate, dishes air dry very
quickly, and a dishwasher may not be needed. Fridges and freezers should be defrosted
regularly to remove ice buildup and door seals should be kept in good condition. Frostfree fridges do not require defrosting, but use more electricity. Fridge and freezer doors
should be closed as quickly as possible. When the oven is used, several dishes should
be cooked at the same time.
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Learners can also be encouraged to have their families experiment with compact
fluorescent lights. While the initial cost of these lights is much higher, they cost much
less to operate and last much longer than incandescent bulbs. A 17-watt fluorescent
light can replace a 100-watt incandescent light. Fluorescent lights usually last 10 times
longer than incandescent bulbs.
In some cases, using one appliance instead of another can save energy. For example,
using the microwave, fry pan or slow cooker instead of the stove top and/ or oven saves
electricity. Of course, choosing not to use equipment also saves electricity. For example,
many families hang up wet clothes instead of using the clothes dryer.
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EXTENDED TEACHING
STRATEGIES
Have the class brainstorm to list the natural resources available in South Africa.
Create a chart and then have learners identify the energy systems involved in
each resource and the pros and cons of using each system.
Have several guest speakers present information about petrochemical and hydroelectric energy sources in South Africa. Have learners prepare questions about
the benefits, costs, and negative impacts of using these energy sources.
Have small groups of learners conduct research and create web diagrams showing
the links among energy use, societal demand, resource use, and environmental
effects. Have each group provide a creative and informative presentation to the
class. It may be possible for learners to repeat their presentations to other
classes or grades.
Present a chart or other resource describing the cost and use of solar energy.
Have small groups of learners develop strategies for reducing energy consumption
in their communities.
Have learners research technologies that have emerged in response to the
problem of non-renewable energy resources and then develop a report on their
findings.
Have small groups of learners design projects based on renewable energy (e.g.,
a solar cooker or solar collector).
Organize a field trip to a power facility.
Have learners research and debate the pros and cons of nuclear technology,
including the international issue of nuclear waste disposal.
Have learners research various sources of power (e.g., coal-fired generating
stations, nuclear power plants).
Develop role-plays based on environmental situations such as the installation of
a hydro line across a farmer's field. Have an environmental panel of learners
listen to the arguments and render a decision on the project.
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