INTERMEDIATE TECHNOLOGY GROUP

ITDG 5: SUSTAINABLE COOKING

Sources of energy in Sri Lanka
Finding a sustainable source of energy, especially for cooking is a major concern for the majority of the population in Sri Lanka. Biomass energy (plant materials, including wood, and animal waste used for fuel) is used by more than 80% of the population. Research suggests that although other forms of energy are slowly becoming available, biomass will remain the main source of energy for the poor.

At the start of the 21st century the average consumption per person in Sri Lanka was about 1.3kgper day, whilst in colder and hilly areas it went up to 2.5 kg. The total national consumption is estimated to be about 10 million tons annually. Although there is a variety of potential sources of biomass (coconut plantations, forest, crop land, processing waste and home gardens), firewood is used a great deal. There are alternatives, kerosene and liquid petroleum gas, but these are often beyond the income of poorer families who can usually find firewood or alternative biomass sources freely available. It is estimated that 10% - 15% of the firewood comes from forests or cotton and tea plantations, home gardens and crops. Packs of firewood are sold in shops and by the roadside. They cost around 50 rupees (about 35p).


Selling firewood in a local store.

Problems with biomass collection
Reliance on biomass creates issues both environmentally and socially. Demand for firewood means a constant search for good sources which means loss of forest with consequent environmental and climate changes.

It is usually Sri Lankan women who take responsibility for the collection of biomass. This takes time and means their ability to do other more productive roles is severely restricted. When there are shortages, the problem becomes more acute. They have to travel longer distances to collect firewood, or they reduce the number of meals cooked, or they use lower quality (e.g. wet) biomass for cooking. Sometimes, they ask school-age children to collect instead, or go into prohibited areas in search of wood. At times of shortage, they are also likely to stop any income-generating activities (e.g. making curd) in order to concentrate on keeping the family properly fed, which means collecting firewood daily.

The process of collecting is in itself sometimes hazardous. There is reduced infant and child care, possibility of snake or insect bites, severe tiredness and allergies from fungi in the forests.


A typical Sri Lankan scene - a woman collecting firewood


A Sri Lankan woman with about two days’ supply of firewood for use in her home.

Problems with using firewood as an energy source
It is not just the supply of biomass that creates problems for families, especially women. Using biomass, especially indoors, creates health hazards. Fires are usually located in the kitchen, the heart of family life where children and women spend most of their time. Smoke is a major problem. Since the fires have no hoods, and often the kitchens have poor ventilation, respiratory problems, conjunctivitis, bronchitis, pulmonary diseases and even cancer are potential outcomes.

The fires themselves are also hazardous. They are often at ground level and therefore easily accessible to small children, making burns an obvious problem. Crouching to attend the fires also leads to back problems.
Finally, there is the question of loss of forests. Because demand is so high, and the most common type of fire is an open three-stone fire, there is considerable waste of energy through the difficulty of controlling the heat in an open fire.



A traditional three stone fire in use in a Sri Lankan home


Three stone fires have their limitations and result in smoke and burn hazards.


Cooking rice on a three stone fire.


The three stone fire
By far the most traditional method of cooking is on the three stone fire. It is also by the cheapest. All you need are three suitable stones of the same height on which your cooking pot can be balanced. The problems are obvious
• smoke and steam can cause health problems
• balancing the pot is vital
• only one pot can be used at a time
• there is no heat control
• it is easy for accidents to happen
• fuel is wasted
• attending to the pot and adding fuel both require bending

There are advantages for most people in using the three stone fire and any new stove needs to consider the following points
• It is convenient
• It involves NO cost at all
• It can cope with a wide range of pot sizes and shapes
• It heats the kitchen area in cold weather
• The smoke is used to process food e.g. fish, meat and cereals to give a longer life.



Tending a three stone fire.

Other existing methods
People in Sri Lanka have been developing improved fires in a bid to cut down fuel waste and health and safety hazards. They have had considerable success. One of the improvements is the Anagi stove, developed to reduce the quantity of biomass needed, to enable two pots to be used at once, and to cut down health risks.



A Sri Lankan potter at work making an Anagi stove



An Anagi stove in use


A raised Anagi stove

It has been estimated that the Anagi stove results in a 50% reduction in biomass usage. As a result it has become very popular with all classes of people, especially when the price of liquid petroleum gas or kerosene has risen.

Continuing issues
Although the Anagi stove improved life for many Sri Lankan households there are still some areas where people are looking to improve its design or develop a new type of stove. Some of the areas suggested by Dr Amerasekara, the Director of Integrated Development Association, A Sri Lankan non-government organisation working with Sri Lankan people are
• a stove capable of being used with larger pots suitable for use by small scale street traders
• a stove capable of coping with a wider variety of sizes and shapes - current stoves can use stoves of between 20 and 50 cm diameter and usually manage round-bottomed pots more safely than flat-bottomed
• some kind of hood or chimney to take the smoke and steam away from the kitchen or area where it is being used
• investigating other sources of fuel to replace wood, especially if it was waste products from other kinds of work
• a more permanent installation - free standing stoves may only last one year whereas installation extends life to five years
• developing a simple stand allowing people to work at the correct height rather than constantly bending or crouching.

What would be the specification for an improved stove?
• Cost is critical. Most current stoves sell for around 100 rupees. (150 rupees = £1) A loaf of bread sells for about 10 rupees in a Sri Lankan market.
• Something for a small street industry would need to be made for less than 1000 rupees
• Able to support pots with a capacity of 100 litres of liquid.
• Capable of supporting a variety of different shaped and sized pots.
• Capable of adapting for either internal or external use.
• Includes a method of smoke extraction for the kitchen.
• Able to use at least two pots simultaneously.
• Uses locally available materials, preferably clay, since this is the cheapest material widely available in Sri Lanka. Metal is also available.
• Draught is also very important - the design would need to generate enough heat, especially for use in a domestic industry.




ITDG subjects
ITDG 1: SUSTAINABILITY CAMPAIGN
ITDG 2: PACKAGING
ITDG 3: SUSTAINABLE POWER
ITDG 4: RAINWATER HARVESTING
ITDG 5: SUSTAINABLE COOKING
ITDG 6 & 7: CARRYING EQUIPMENT
Design Contexts
Developing design briefs
Images to stimulate students’ thinking (images still to come)
Advice on finding clients
Generic design contexts
Advice on specific design briefs
CAT specific design briefs
Loughborough University specific design briefs
ITDG specific design briefs
CAT support information
Loughborough University support information
ITDG support information