Biogas as an alternative Energy Source for Papua New Guinea

More than 80% of the population in Papua New Guinea (PNG) depends on firewood for its energy needs. This includes the less affluent households in towns and cities and the majority of people living in rural households. It is estimated that some 7.0 million people in PNG depend on firewood for their daily energy needs.

However, the collection and use of firewood causes deforestation and forest degradation and the emission of greenhouse gases into the atmosphere, which contributes to global warming and climate change.

Therefore, the international community is now calling for tropical countries with large tracts of rainforests to address deforestation and forest degradation to mitigate global warming and climate change.

Moreover, due to many social issues associated with women and children in the collection, transportation, and use of firewood in poor households in many developing countries, human rights groups are now advocating for the use of more efficient cooking stoves and energy sources as alternatives to firewood.

The cost of firewood in Port Moresby is almost the same as kerosene and imported charcoal, but costs less than electricity and propane gas (Table 1 – shown below). Comparing firewood with biogas, firewood would cost K500 – K800 more than biogas as a fuel for cooking and heating per annum.

Consequently, PNG needs to look at alternative sources of energy for the mass of its population, which depends heavily on the use of firewood. These alternative energy sources should contribute to the alleviation of climate change and many of the social, economic, and environmental issues associated with firewood and its use as an energy source.

It is well established that biogas can be a source of low-cost, clean energy systems that can be an alternative to firewood for poor households in many developing countries. Biogas technology has been tested and developed in many parts of the world for poor households.

However, the use of biogas has been minimal due to the lack of attention given to the technology. This is due to the many technical and policy issues associated with its use in different countries. But with the onset of the climate change issue, the production and utilization of biogas has now gained prominence and it is a climate change mitigation measure under the Clean Development Mechanism of the Kyoto Protocol.

Table 1. Cost of different fuel types used for cooking and heating in Port Moresby

The co-benefits of biogas systems are many and vary with the type of design that may be in use. Generally, however, the use of a biogas system will mitigate climate change, assist in reducing the rates of deforestation and forest degradation in many tropical countries, take away the burden of firewood collection and transportation by our children and womenfolk, eliminate eye irritations for our womenfolk during cooking, and eliminate the chances of our womenfolk 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, bio-methane is more efficient than firewood.

Waste discharged from a biogas system is a good source of organic fertilizer that can be used to grow plantain, 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 than carbon dioxide. However, burning bio-methane from a biogas system during cooking and heating emits carbon dioxide and water into the atmosphere as waste. And since carbon dioxide is a greenhouse gas that is 21 times less potent to the climate than methane, there is a reduction in the impact of greenhouse gases on our environment and climate when we combust bio-methane during cooking and heating.

I have set about to develop a low-cost biogas system that uses household waste to generate bio-methane that can be used for both cooking and heating. The biogas system is simple and would not cost much to construct. One would spend some money at the initial stage to construct the biogas system, but after that, the system can generate bio-methane without the need for any costly maintenance and can last many years if good care is taken of the system.

The biogas system can generate bio-methane all year round, and all one has to do is feed the system with waste food every week. Ripened and rotting fruits such as bananas, guavas, and pawpaw are good sources that can feed the system. Cooked foods such as taro, vegetables, banana, sweet potato, English potato, yams, rice, meat, and grease can also be used.

Waste from lemons, oranges and pineapples should not be used in the system since they are acidic and can kill off bacteria that break down food waste in the bio-digestion tanks. 

Biogas has already been produced and utilized on a commercial scale by New Britain Palm Oil Limited in Papua New Guinea. Wastewater from several oil palm mills in West New Britain Province is used to produce biogas for the generation of electricity, which is utilized by the company and the excess power is sold to PNG Power Limited.

The production and utilization of biogas for household use is just the tip of the iceberg. Biogas production and use have the potential to address renewable energy, sustainable development, environmental sustainability, climate change mitigation, REDD+, waste management, and human rights issues in PNG. However, these potentials can only be realized if we develop proper policies and legislation within the many development sectors to address climate change more holistically.