IDEP Appropriate Technology Guide

A p p r o p r i a t e Te c h n o l o g y
No 12.
P e r m a c u l t u r e R e s o u r c e B o o k M o d u l e 12 .
Pe r m a c u l t u r e , S o l u t i o n s f o r S u s t a i n a b l e L i f e s t y l e s
New technology is constantly being invented to improve life. A good idea is an idea that helps
people to evolve and helps societies to become better and more sustainable.
However, sometimes technology has negative impacts on people and the environment, and
often new technology is expensive to buy and difficult to maintain, for example:
• Cars are tools for transportation, but they use oil and petrol which is taken from the earth,
this supply will not last long and cars are causing pollution problems all over the world
• Electricity from generators also uses fuel and causes pollution
• Tractors can plough fields quickly, but they are difficult and expensive to maintain, and
they cannot be used on sloped land
A lot of technology that helps make
life easier is actually helping to create
a huge problem that the whole world
now faces, this problem is called “global
warming”. Too much carbon dioxide
(CO2) in the atmosphere is altering
the earths natural cooling cycle. Ice
and snow is slowly melting in some
places and the temperatures are slowly
This situation will only get worse unless changes are made all over the world and more
sustainable technologies are used. Even small countries have continuous needs. Because of
this, the best technologies to use are sustainable technologies that suits the needs of the local
people. This type of technology is called “Appropriate Technology”.
Appropriate technology has certain characteristics, such as:
• It is easy to understand
• It can be sold, owned and maintained
• It reduces electric use, labour, fuel use and other energy use
• It uses natural, environmentally friendly materials and
reusable energy
Some examples of appropriate technology:
• Diesel vehicles and motors which are run using
coconut oil
• Electricity which is created using energy from the
sun, wind, water and even manure
• Using animals for labour, such as buffalo, cows
and horses for transportation, field work and other
labour, instead of only being kept for consumption
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Clay Ovens and Stoves
Stoves and ovens made from clay are a simple technology, which can
be easily made and will provide many benefits, such as:
• Conserves firewood, which will save money, labour and helps protect
the environment for the future
• Produces less smoke, which helps reduce pollution and health problems
• Can use alternative fuel, such as rice husks, coffee husks, sawdust or charcoal bricks, as a
replacement for wood
Clay Stoves
clay stove
cross section
Clay stoves are commonly used in many regions. They are very
simple to use and will conserve firewood because the clay helps
to provide heat for cooking. Clay stoves are made from clay
(75%), dried cow manure (25%), small amount of cement (5%),
a clay stove with
2 burners and a chimney
and a little water to make the mixture moist but not wet.
Clay Ovens
Clay ovens will work better than clay stoves. They can be
made in many different shapes, small or large, and can also
function as a heater or as a stove. These ovens can also have
stove cross section
a chimney to draw smoke out of the kitchen to make the air
safer for peoples health. Clay ovens are also made from clay,
dried cow manure and a small amount of cement.
Method 1
Use clay bricks for the bottom and sides. Cover them with a thick render made from clay (75%),
dried cow manure (25%) and cement (5%, if available). Use wire to shape a frame for the oven
top. Make 2 or 3 holes in the center of the wire, about 10 cm wide for cooking pots. The top
should be flat, so the cooking pots can be placed on top flat and not slanted. Make one more
hole at the back of the oven for a pipe / bamboo chimney, to let smoke out. Cover the wire with
the clay mixture, use a layer of about 10 cm thick so the wire is in the middle. Make a door at the
front that is large enough, it must be 10 cm thick and should fit very well to stop smoke and heat
from escaping. Make a round thin metal sleeve to hold the bottom of the chimney. Place a pipe
or bamboo into the prepared hole and use clay to seal all the gaps between the metal and
the chimney pipe. Make a lid for the cooking pot hole to cover the holes when cooking pots
are not being used. These lids should fit tightly to stop smoke and heat from escaping.
Method 2
Follow the same steps as method 1, but use a wire frame mold to
shape the whole oven frame. Make sure that the thickness of the
oven is 10 cm or more.
Pe r m a c u l t u r e , S o l u t i o n s f o r S u s t a i n a b l e L i f e s t y l e s
Charcoal Brick Cooking Fuel
Firewood is expensive and takes hard work to collect. Firewood also creates a lot of smoke.
Charcoal bricks is a very good cooking fuel that lasts a long time and produces only a little
smoke. Charcoal bricks can be made easily using local materials.
Making Charcoal Bricks
To make charcoal bricks, use the following steps:
• Cut the bottom off a drum. Turn it over and cut a small circle, 20 cm wide, in the middle of
the other end. Make sure any sharp edges are hit down
• Fill the drum with fresh bamboo leaves, thin split bamboo (not dry bamboo), coconut
shells and husks, coffee husks, rice husks and leaves (bamboo leaves are best). Burn
these materials slowly and stir the fire occasionally with a wooden pole through the hole
in the top of the drum. Occasionally add some
splashes of water to slow the burning process.
Add more materials if available. When the
material has all burned and turned into black
pieces of charcoal, put the fire out with water.
The black charcoal will be left at the bottom
• Make a glue paste. Crush some fresh cassava
root and take the sap that forms. Add some
water to make a thick glue paste
Or, crush some cassava stems (without the
bark) and mix with water. Leave the mixture
to settle. This mixture will separate into liquid
at the top and a thick paste at the bottom.
Pour off the liquid until only the paste remains
• Combine the black charcoal with this cassava
glue / paste (90 to 95% charcoal and 5 to
10% cassava paste. Put this mixture into brick
molds and leave in the sun until dry
Using Charcoal Bricks
Charcoal bricks can be used to cook with open fires, clay stoves or clay ovens. The bricks will
burn slowly and produce a constant heat.
Start a small fire with wood sticks and add the charcoal bricks when the fire is lit. The bricks
will slowly burn themselves. Add some more wood sticks if you need to increase the heat, and
add more charcoal bricks as needed.
M o d u l e 1 2 : A p p r o p r i a t e Te c h n o l o g y
Drum Ovens
An old drum can be used to make a simple, large oven. The
materials needed are sand, rocks and banana leaves.
This method uses less wood to cook the same amount of food as
a cooking fire. Also, by using a drum oven to cook, the food will
contain more nutrients compared to boiling or frying food.
How to cook:
• Cut off the top of a drum. Clean the inside with detergent and water. Leave in the sun to dry
• Fill the drum half way with sand
• Collect some hand sized rocks. Make a fast fire with dried palm leaves, bamboo leaves,
small wood sticks and other materials, to burn the rocks (don’t use rocks from the river
because they could explode!)
• When the rocks are very hot, use a shovel to put to layers of rocks on top of the sand
in the drum. Then put 2 layers of fresh banana leaves on top of the rocks. Place food on
top of the banana leaves. Meat, fish, cassava, sweet potato, potatoes, corn, bananas,
eggplant, mushroom, pumpkins, yams, carrots and more can be cooked. Then add 2 more
layers of banana leaves to cover the food, and 2 more layers of hot rocks on top of the
banana leaves. Cover the top with any material, like metal, plywood or an old cloth. Leave
for 2 hours
• Remove the cover, rocks and banana leaves, and some tasty food is ready to be eaten!
• Instead of cutting the top off the drum, just cut the drum in half. In this way
you will have 2 ovens!
• This same method of cooking can be used by digging a hole in the ground. In
areas with sandy soil, this method will be much more simple to use
Sawdust Stoves
This idea was taken from Lik Lik Buk, a guidebook from Papua New Guinea.
This stove uses sawdust as cooking fuel. The stove may also work with
dried rice husks or coffee husks, but these fuels should be tested first
to see which materials work best. This method of cooking will produce
little or no smoke. You can make and use a cement stove. To make a
cement stove, you will need materials such as a mold, which could be
an old bucket or can, some wire, fine sand and cement, about 1/4 bag of
cement for one stove.
Pe r m a c u l t u r e , S o l u t i o n s f o r S u s t a i n a b l e L i f e s t y l e s
The following steps can be used to make the stove:
1. Make a small hole in the bucket, about 3 cm from the bottom of the bucket
2. Mold wire so that it fits inside the bucket, but slightly smaller so it is not touching the
sides and bottom of the bucket. The wire should be 2 cm below the top of the bucket.
Don’t let the wire cover the hole at the bottom of the bucket
3. Mix the cement and sand, about 1 part cement to 3 parts sand. This should be a fairly
dry mix. Put about 2 cm of cement into the bucket (at the bottom), then place the wire
mold into the bucket so it sits on top of the wet cement. Place a tin can in the bucket.
Put a bamboo or wood through the small hole at the bottom of the bucket, and position
it so that it is just touching the tin can. Place a rock into the tin can to prevent it from
moving. Carefully fill the space between the bucket and tin can with the cement mixture.
Fill it evenly up to the top of the bucket. The wire mold functions as the frame for the
cement stove
4. Leave for 1 hour, then carefully make 2 cuts in the top of the cement, about 1 cm deep
and 2 cm wide. These cuts will provide important air flow when cooking and are essential
for the stove to work
5. When the cement has dried, carefully
remove the tin can by slowly twisting
and pulling it. Also remove the
bamboo at the bottom of the stove
6. Put the bucket of cement in a dry,
dark place and leave for 2 days
7. To remove the bucket, gently tap the
sides of the bucket, then turn the
bucket over and shake it until the
stove slides out. Be careful not to let
the stove fall and crack. Cover the
stove with a damp cloth and keep it
moist for one week to preserve the
cement. After this time, the oven is
ready to be used!
How to use cement and sawdust stoves:
1. Take 2 pieces of bamboo. Place one piece in the center of the stove in a vertical (straight
up) position and place the other piece through the hole so that it is touching the first
piece of bamboo
2. Pour sawdust into the stove from the top until the stove is full and tightly packed
3. Carefully twist and remove both pieces of bamboo without moving the sawdust, so the
stove has an ‘L’ shaped tunnel inside
4. To light the stove, take a thick piece of dry wood and dip it in kerosene, then put it in the
bottom hole of the stove, light a match and drop it into the stove from the top hole
5. The sawdust will slowly burn. Once the sawdust in the middle is bright red, the piece of
wood can be removed. The stove will provide constant heat for 2 hours. If more heat is
required, place another stick into the stove
M o d u l e 1 2 : A p p r o p r i a t e Te c h n o l o g y
Tin Metal Stoves
Tin metal stoves use rice husks or coffee husks to
burn instead of firewood. These stoves are designed
so that air enter through the bottom and keeps the
husks burning continuously.
Tin metal stoves last a long time and a blacksmith
can easily make them.
Gas Stoves
Gas stoves are slightly more expensive than firewood stoves because you must buy the stove
and gas bottle, however the benefits received are more than worth it. Using these stoves is
much easier, faster and cleaner than using firewood stoves. They do not produce any smoke.
Solar Cookers
Solar cookers use heat from the sun to heat food or cook it
slowly. Food can be cooked first on a stove or fire until it is
ready and then it can be kept in the solar cooker to keep it hot.
Tin foil and glass are used to reflect and catch sunlight and
heat, and insulating materials (such as coconut fibre or kapok)
or wood painted black is used to store the heat. Solar cookers are
good for cooking soups, rice, corn and more.
Use materials that are inexpensive and easy to find. The cookers can be a box shaped closed
cooker or a simple open cooker.
Pe r m a c u l t u r e , S o l u t i o n s f o r S u s t a i n a b l e L i f e s t y l e s
Solar Driers
Solar driers can be used to dry fish, meat,
vegetables and fruits, and it will also keep food
protected from insects and other animals. This
tool will dry food much faster, for example drying
fish takes 1 week normally, but with a solar drier
it only takes 2 days.
Solar driers reduce food waste, especially during harvest time, when there is sometimes too
much food to be eaten or sold. The nutrients in the food will stay in the food, and dried foods
can easily be traded or sold. There are many different types of solar driers, but we will only
explain 2 of these types.
Plastic Solar Driers
Plastic solar driers use a very simple design. The frame is made of wood and is wrapped tightly
in clear plastic. Inside are shelves made with a wooden frame and a base of insect wire.
The wooden legs of the shelves are put into tins filled with water
to prevent ants from damaging the food. The back of the drier can
be left open to make access easier. At the bottom, front side of the
drier, an extra section can be added to catch hot air. Wrap the top
of this section with clear plastic. Hot air will be collected
inside and will rise up to the top of the drier, because hot
air always rises, and then leave through the insect wire
at the top of the drier. This method is called ventilation,
which will help to speed up the drying process.
Wood and Glass Solar Driers
This type of drier will work well to quickly dry food
materials, such as:
• Large fish, in 3 days
• Small fish, in 1 day
• Vegetables, in 1 day
• Meat, in 3 days (for meat that has been cut into slices 3 cm thick)
This type of solar drier is more expensive to make, but it will dry food faster and will last longer
than plastic solar driers. This type of solar drier is also very easy to clean. If these driers are
maintained well they will last up to 5 years, or more. Just like plastic solar driers, this tool works
by using ventilation / air flow.
M o d u l e 1 2 : A p p r o p r i a t e Te c h n o l o g y
Natural Coolers
If meat, vegetables and fruits are cooled, they will last much longer. For some remote areas,
refrigerators are too expensive and use a lot of electricity to work.
The Coolgardie safe, which was invented in Coolgardie, a town in Western Australia, is a simple
way to store food and keep it cold, while preventing insects and animals from touching the
The safe is a wooden box that has shelves inside to place food on. This box can be as big or
as small as you need.
One side opens like a door, and all
of the sides have insect screens with
wooden edges. The insect screen will
allow wind to blow through but stop
animals and insects from entering.
On top of the box place a tray that is
filled with water. Attach a large piece
of hessian to the tray and position it so
that it hangs down over 2 sides of the
box. The hessian / cloth draws water
from the tray down to the sides.
Wind blows the wet hessian and this keeps the food inside the box cold. Add water to the tray
as needed. The Coolgardie safe can be hung or placed on a stand. The safe should always be
placed outside so that it receives wind.
Clay Pots
Clay pots are very good for storing food, especially vegetables and fruits. In this way the food
will stay fresh for a few days longer.
Place food in a clay pot and cover it with a damp cloth. Make sure the cloth stays wet and keep
the clay pot out of the sun. Or, use 2 clay pots, on clay pot inside of another clay pot. Put a
layer of damp sand in between the two pots. Make sure the sand stays moist and cover the
pots with a wet cloth. Keep out of the sun.
Pe r m a c u l t u r e , S o l u t i o n s f o r S u s t a i n a b l e L i f e s t y l e s
The cost of electricity is expensive
and it will only get more expensive,
so conserving electricity is very
important. Conserving energy is
something that should be done by
people all over the world.
Natural electricity production is
much better for the future. It also
produces very little pollution and can
natural energy sources & systems
be used by all levels of society, from
individual needs to public needs.
Hydro-electric Systems
Hydro-electric systems use flowing water to create electricity. Water from rivers, dams or
lakes run through a pipe that goes down hill, the water then causes a wheel to spin around
in the hydro-electric unit, which turns a turbine and creates electricity. This electricity is then
stored in batteries until it is used. Hydro-electric systems can be many different sizes, from
micro-hydro systems which supply electricity to a few houses or a village, to very large hydroelectric systems that run from large lakes or dams and can supply electricity to an entire city
or province.
Using small hydro-electric systems will provide many benefits:
• They produce a small but continuous supply of electricity
• They are more environmentally friendly compared to
large hydro-electric systems, both in setting up and
in long term impacts
• Maintenance is easier compared to large hydroelectric systems or other systems, like solar systems
• They use smaller storage batteries
larger microhydro systems
Biogas Systems
A biogas system collects methane gas, which is a flammable gas used for cooking, running
gas lights, running internal combustion machines and used to create electricity.
Methane gas is naturally created when animal manure, human manure, rice husks, leaves,
water plants and grasses decompose. In a biogas system, these materials are collected and
placed in a biogas tank, so that the gas which is created becomes trapped in the tank and can
be used. New materials can continuously be added to the tank, and the old materials can be
taken out and used as a very high quality fertilizer.
M o d u l e 1 2 : A p p r o p r i a t e Te c h n o l o g y
There are many benefits which can be achieved by using this system:
• The gas and electricity
produced comes from
available and inexpensive
gas pipe
• Gas replaces the need for
firewood, which helps to
reduce smoke pollution
gas cooker
• The manure and other
materials used will
continue to store nutrients
needed by plants, in
fact because of the gas producing process, the nutrient levels will increase. After these
materials have decomposed and produce methane gas, the materials can be reused to
make compost or used directly on crops as fertilizer. However, be careful because this
creates a very strong fertilizer
• Almost all bad bacteria in the manure, which can spread disease, are killed in the biogas
tank so this will reduce the chances of disease spreading to humans and animals
This system is already being used in many countries and is a very good technology. There
are many different designs for biogas systems, depending on the type of materials available,
money and what the system will be used for.
Some basic facts about biogas systems:
• 1 m3 (1 m x 1 m x 1 m) of methane gas provides: Gas to cook 3 family meals, or 6 hours
of light from a light bulb, or 700 ml of fuel to run a 2-horsepower generator for 2 hours, or
1.25 kw of electricity
• 1.5 m3 of tank size per person will provide enough methane gas for ever day needs (or, 15
m3 for 10 people)
Biogas systems are anaerobic (no oxygen), so they must be made air tight and water tight.
Maintenance of the system includes maintaining water levels, pH levels, temperature, material
input mixtures, protection from harmful materials and tank stirring management.
To create and maintain a biogas system, research and technical knowledge are needed, this
information can be found through books, the internet or NGOs actively working with this
system. This will bring better skills and knowledge, as well as the many benefits which can be
achieved by using biogas systems.
Pe r m a c u l t u r e , S o l u t i o n s f o r S u s t a i n a b l e L i f e s t y l e s
Solar Systems
A solar system uses sunlight and solar panels to create electricity.
The solar panels must be placed so they receive
a lot of direct sunlight, not shaded by buildings,
trees and so on. However, if the solar panels
become too hot they will not work well. This
will happen if the panels are touching metal
or tin roofs. If possible, keep them away from
tin roofs or put lots of insulation (old material,
cardboard, bamboo, wood and so on) between
the roof and panel.
Solar systems are already being used in many countries. These systems will provide electricity
anywhere, and with the right knowledge they are easy to set up. However, it is also important
to have knowledge of how to maintain and operate them properly, the batteries especially have
to be looked after well, because if they are maintained or used incorrectly they can break very
These systems are expensive, but they will provide environmentally friendly electricity for
Wind Systems
Wind can also be used for making electricity.
Wind generators use propellers which turn when the wind blows, this
causes other components to also turn which transmits power to a water pump
or generator. The energy which is created is then stored in large batteries used to provide
electricity. Wind generators come in many sizes, from small generators which can create
enough electricity for a household, to very large generators which can create enough electricity
for many houses.
In some countries, many large wind generators are made and placed in areas where the wind
is strong enough to create a lot of electricity. These areas are called wind farms.
In the future, large wind farms could provide electricity for entire cities, replacing diesel
generators. To make this possible will require working with the government and businesses.
Wind farms take a lot of money to build, but they are more sustainable and will save money in
the future. The wind farms could be part of a national system and can be combined with other
natural electricity sources.
M o d u l e 1 2 : A p p r o p r i a t e Te c h n o l o g y
Oil Fuel
Cars, trucks, motor bikes and other vehicles create a lot of pollution problems in the world today.
The pollution starts from the process of mining to access the fuel, and continues until the fuel
is used to run motor vehicles. New technologies have been created to reduce these problems,
such as electric cars and hydrogen cars. There are also other more simple technologies, such
as using coconut oil to run diesel machines, this will be explained briefly in this manual.
Coconut Oil for Diesel Machines
Cars and diesel machines can be run on high quality coconut oil. With some slight
changes and an oil heater, cars can also be run on used frying oil! Information
about this technology and more can be found in books and on the internet.
Coconut oil for diesel machines and cars is the simplest and most appropriate
method to use, some research and testing about this method has already been
undertaken. Coconut oil can be used for all diesel machines, including cars, trucks, hand
tractors, rice mills, small generators, pumps and more. The coconut oil used must be very
high quality, because if not it could destroy the machine. The coconut oil from the markets
cannot be used, because it is usually very low quality.
To use it, combine 20 parts coconut oil to 1 part kerosene (5%). This will help make the liquid
thinner. In cold areas, combine 10 parts coconut oil to 1 part kerosene (10%). This method has
been successful in Bouganville, Papua New Guinea, for many years and is now being used in
Fiji and Thailand.
Water Pumps
Machine water pumps are commonly used but they are expensive and need fuel to operate.
Following are some example of simple water pumps which do not need fuel to operate and are
much easier to maintain.
Ram Pumps
A ram pump uses water pressure created by gravity to flow water a long way uphill. Water from
a spring or other water source can be collected in a small tank / container. The water must be
clean, because if it is dirty it will cause problems. The water then flows downwards through a
pipe, which is usually 10-20 meters long. The presser is created as the water flows downwards.
The water flows into the pump, creating air pressure and pumping water through
smaller pipes back uphill. Water can be pumped through smaller pipes
as far as a few hundred meters. The water can then be flowed to water
storage containers.
By using this type of pump, water can be flowed in large amounts, and if
the water source is constant, the water can be flowed all year long. This
tool is a great economical solution for water supply problems.
Pe r m a c u l t u r e , S o l u t i o n s f o r S u s t a i n a b l e L i f e s t y l e s
Foot Pumps and Treadle Pumps
These pumps can be used to pump water from a bore or well, and
can also be used to pump water from a spring or river.
These pumps use 2 boards which are attached to 2 cylinders
below them. To operate the pump takes a similar movement as
someone walking, moving the boards up and down with their
feet. Air pressure is created and sucks the water up through a
pipe into the cylinders and out the top, to then be directed to
wherever you need it, like for house or garden needs.
It is very similar to a hand pump, but more water can be moved
for less effort.
Solar Power Water Pumps
Solar powered water pumps are used to add oxygen
to ponds. The pump is run by using a small solar
panel which creates electricity for the pump.
These are great for fishponds and can also be used
in water cleaning systems.
Windmills use wind power to pump water from underground to above
ground, to be used for house needs or irrigation. A windmill is like
a giant fan.
The wind turns the blades of the windmill, which as they
turn will force a piston to move up and down, sucking water
to above ground through an underground pipe.
Elevated Water Storage
Water can first be moved into an elevated
tank, and then run through pipes to where
the water is needed.
To move water into an elevated tank, take
water straight from a roof using bamboo
water collection, use a treadle or ram
pump, or any other type of pump.
M o d u l e 1 2 : A p p r o p r i a t e Te c h n o l o g y
Other Simple Tools
Pedal Powered Grinders
A simple but effective technology, a grinder that can
be used to grind corn, rice, nuts and more.
This grinder is connected to a bicycle, and the bike
chain, which would normally turn the bike wheel, is
attached to a cog which spins the grinder.
This is much easier than pounding corn and much cheaper than using a petrol grinder.
Oil Press
An oil press is a tool used for extracting oil from seeds, nuts and other plant materials which
produce oil, like coconut, candlenut and avocado. The oil that is produced is of high quality and
it will greatly improve nutrition, especially for children, or it can be sold or traded. Good quality
organic oils are a possible export market.
Using the Internet
The internet is one of the most important technologies for the future. The internet contains
large amount of information which is useful for developing a sustainable future. With the
internet, we will be able to share technologies and information with partner groups from all
over the world.
Pe r m a c u l t u r e , S o l u t i o n s f o r S u s t a i n a b l e L i f e s t y l e s
M o d u l e 1 2 : A p p r o p r i a t e Te c h n o l o g y
Pe r m a c u l t u r e , S o l u t i o n s f o r S u s t a i n a b l e L i f e s t y l e s