BY NALAU BINGEDING
More than 80% of the population in PNG depends on firewood for cooking and heating. This includes the majority of people living in rural households as well as the less affluent households in our towns and cities. Despite lack of data, it can be estimated that some 7 million people in PNG depend on firewood for cooking and heating (Figure 1).
However, the collection and use of firewood for cooking and heating contributes to the issue of deforestation and forest degradation. Deforestation and forest degradation are responsible for the emission of greenhouse gases into the atmosphere, causing global warming and climate change – a global phenomenon that is now threatening the very existence of life on earth.
Moreover, due to many social issues associated with women and children in the collection, transportation and the use of firewood in poor households in many developing countries, NGOs and human rights groups are now advocating for the use of more efficient energy sources as alternatives to firewood.
The international community is now calling for all tropical countries with large tracts of rainforests to address deforestation and forest degradation in order to mitigate global warming and climate change. PNG is one of those countries called upon to address global warming and climate change because it has some 33 million hectares of forest, covering some 70 percent of its landmass.
Consequently, PNG needs to look at alternative sources of energy for the mass of its population, which depends heavily on firewood. Besides the production of energy, these alternative sources should also contribute to the alleviation of poverty, human rights issues, climate change and many other social, economic and environmental issues associated with the collection and utilization of firewood.
It is well established that biogas can be a source of clean and low-cost energy system that can be an alternative to firewood for poor households in many developing countries (Figure 2). Biogas technology has long been tested and developed in many parts of the developing world for poor households.
However, the use of biogas has been minimal due to lack of attention given to the technology and the many policy issues associated with its use in many developing countries. But with the onset of the climate change issue, the production and utilization of biogas has now gained prominence and it is a mitigation measure under the United Nations Framework Convention on Climate Change.
The co-benefits of biogas systems are many and vary with the type of design that is in use. Generally, however, the use of a biogas system will mitigate climate change, assist in reducing the rates of deforestation and forest degradation, take away the burden of firewood collection and transportation by our children and womenfolk, eliminate eye irritations for our womenfolk and children during cooking, and eliminate the chances of our womenfolk and children contracting breathing problems and diseases as a result of prolonged exposure to smoke from combustion of firewood.
Bio-methane from a biogas system has a higher energy value than firewood, and 1kg of biogas can cook three times more food than 1kg of firewood. Therefore, biogas is a more efficient energy source than firewood.
I experimented in 2014 with developing a low-cost biogas system that used household waste to generate bio-methane for both cooking and heating. The biogas system I designed was simple and cost less than K200 to construct (Figure 3). And for any other design it would cost some money in the initial stage for construction, but after that the biogas system can generate bio-methane without the need for any costly maintenance and can last many years if good care is taken of it.
Biogas systems can generate bio-methane all year round, and all one has to do is feed the system with waste food on a weekly basis. Ripened and rotting fruits such as bananas, guavas and pawpaw are good sources that can feed these systems. Cooked foods such as taro, vegetables, banana, sweet potato, English potato, yams and rice can also be used. Meat, greasy foods, lemons, oranges and pineapples should not be used in the system.
I discovered that when ripened and rotten fruits such as guava and banana were used for biogas production, the waste discharged from the biogas digester was vinegar. It was not my intention was not to produce vinegar, but it is one of those byproducts of biogas that can be generated from household food waste.
Waste discharged from a biogas system is a good source of organic fertilizer that can be used to grow bananas, flowers, vegetables and fruits. The waste, however, is not a good fertilizer for tuber crops like taro and sweet potato.
Bio-methane is a greenhouse gas that is 21 times more potent to the climate and the environment than carbon dioxide. But by burning bio-methane from a biogas system during cooking and heating, we consequently emit carbon dioxide and water into the atmosphere. And since carbon dioxide is a greenhouse gas that is 21 times less potent to the climate than bio-methane, there is actually a significant reduction in the impact of greenhouse gases on our environment and climate when we combust bio-methane during cooking and heating.
Biogas is already produced and utilized on a commercial scale by New Britain Oil Palm Limited in PNG. Waste water from several oil palm mills in West New Britain are used to produce biogas for generation of electricity, which is utilized by the company for its operations and the excess is sold to PNG Power Limited (Figure 4). The current capacity for biogas production by New Britain Oil Palm Limited is 4 megawatts, but there is potential for more as the company has oil palm mills in Morobe Province, Madang Province, Milne Bay Province and in the Solomon Islands.
The production and utilization of biogas for household use is just the tip of the iceberg. Biogas production and use has the potential to address renewable energy, rural development, sustainable development, environmental sustainability, climate change mitigation, REDD+, waste management, human rights, and many other social, economic and environmental issues in PNG. However, these potentials can only be realized if we develop proper polices and legislations within relevant development sectors to address climate change in a more holistic manner.
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