Practical Action, the international NGO produce an annual document, PPEO 2014 (Poor People Energy Outlook) on energy for the poor on the bases of sustainable development .This is a review of the 2014 document which conceded with the World Future Energy Summit (WFES) convened in Dhabi in 19-22 January, 2015. This part focuses on energy for households.
Solutions for water heating
For those using a three-stone fire or traditional stove, water is often heated using the dying embers of the fire once the cooking is completed. More efficient biomass, liquid-fuel or stoves cannot be used in this way.
However, studies by Practical Action in Kenya have shown that for short, rapid cooking, such as making tea, even low-income households will use modern stoves if the purchase price is affordable or revolving finance is available. This is because they save a lot of time: in the Kenya case study, around 2.6 hours per day.
For heating larger amounts of water for washing, simple low-cost solutions can be effective such as using black polythene containers placed in the sunshine. Direct solar water heaters comprising a tube fitted in a zigzag fashion onto a board can produce water to 60°C, even in temperate.
The minimum standard for access to clean cooking solutions should cover fuel use, time, stove efficiency and pollution. As with lighting, we think the standards proposed by the GIZ EnDev programme are appropriate (GTZ-HERA, 2009), combined with WHO’s indoor air quality guidelines (WHO, 2006) and a time-limit for the collection of fuels.
• 1 kg wood-fuel or 0.3 kg charcoal or 0.04 kg LPG or 0.2 litres of kerosene or biofuel per person per day, taking less than 30 minutes per household per day to obtain 3 minimum efficiency of improved solid fuel stoves to be 40% greater than a three-stone fire in terms of fuel use
• Annual mean concentrations of particulate matter
Space heating is an important function of household stoves and heating appliances, particularly at higher altitudes and during cold seasons. Despite this, it is often overlooked by policymakers and designers of stoves programmes. Depending on customs and traditions, people either want to use their cooking stove to also provide warmth, or they have a separate stove for heating their home. It is estimated that half a billion people in South and South-East Asia alone use stoves for space heating, whether for everyday use, just during cooler seasons or at night.
In the mountainous areas of Asia, households generally use 70–80% of primary energy directly for cooking and 20–25% directly for space heating. However, when the actual service provided by the energy is calculated, an estimated 60% contributes to heating the surrounding space and only 40% goes into cooking.
This is because much of the heat generated by the cook stove dissipates into the surrounding air, thereby heating the room. Improved stoves focus much more of this escaped heat on the pot, funnelling smoke and hot gases out through a flue or chimney. The unfortunate trade-off of this efficiency is that householders might need to have a separate fire to keep warm.
It can be difficult for poor people to keep indoor temperatures at a reasonable level during cold seasons. This in itself causes health problems, while some of the solutions also have health risks and involve a considerable investment of effort and money.
Health impacts of cold. Mortality rates rise progressively when outdoor air temperatures fall outside the range of 20–25°C in particular through an increase in the likelihood of cardiovascular and respiratory disease.
HelpAge International (2009) report that older people (and small children in their care) have been severely affected in Kyrgyzstan, where the capacity to generate hydroelectric power during the long winter months has been limited. To reduce their fuel consumption and costs, people often close the doors and windows. This exacerbates the amount of smoke in the house and exposes people to greater risks associated with indoor air pollution.
The majority of poor rural people living in mountain regions use woodfuel for space heating. Space heating requires large amounts of fuel, forcing people in cold climates to spend many hours gathering firewood or spend a larger proportion of their incomes on woodfuel. A study in Garhwal Kingdom in India showed a marked increase in the use of biomass with increasing altitude, and fuel use was shown to be two to three times greater in winter than in summer.
The firewood consumption was reported at around 1.07 kg/person/day below 500 m altitude, rising by an additional fuel requirement of about 0.8 kg/person/ day per 1,000 m, to reach 2.8 kg/person/day above 2,000 m. A Practical Action study in the high hills in Nepal found that households spent an average of 19 hours of labour (number of people × time taken) per week gathering fuel.
Solutions for keeping warm safely and affordably in cold regions include choosing good stoves and heaters, and combining this with changes in building design and better insulation.
Many modern cook stoves are designed to reduce the extent to which the fire’s heat dissipates into the room. However, there are some designs that do use the heat from the stove for space heating as well as for cooking, while preventing smoke from getting into the room.
Separate heating stoves are used in countries where heat is not needed all the time. Typically, they are enclosed stoves with a flue pipe. Some allow a kettle to be placed on the stove top. Chimney stoves made of steel (for cooking and heating) are used in many countries in Asia. Well-made and well-maintained stoves can provide a good level of warmth. There are still risks of burns from the hot exterior of the stove. An option where people like to see the fire is to use a smoke hood, leaving the fire partly exposed.
Buildings designed for warmth. Passive solar design can lower energy requirements for heating. In the southern hemisphere, windows should face north (±15) for optimal solar benefit (staying cool in summer and reducing heat loss in winter). Placing the main door away from the wind and using a buffer space such as a porch can also make a difference. The choice of materials can make a difference. Choosing those with a high thermal mass allows the material to store heat during the day and release it slowly at night.
By Alula Berhe Kidani,