Self-Sustaining Households by Waste Alone

Our huge dependency on the centralized waste treatment structures along with the increasing demand in energy is driving the need for decentralized, alternative structures at a small scale. How far can these technologies and systems go to sustaining the households? Australia has the answer for it. 

The households are responsible for consuming almost twenty-six percent of the energy in Australia and produce about thirty percent of the total solid waste that’s generated. Energy, which is used in Victoria’s households and throughout the world comes primarily from the centralized thermal plants where 2/3^rd electrical energy generated are lost in the distribution.

As for waste water production in the households, the human excreta is taken out with inconsistent amount of water and treated in costly, centralized, large plants to be discharged into the water bodies later. Simultaneously, the solid waste is even collected as well as transported to long distances to the big landfilled and centralized plants. 

Wastewater and waste often pose an environmental and health hazard, especially where the right treatment infrastructure doesn’t exist. But they are an important resource in an inappropriate place that may be used for obtaining energy as well as valuable products by a wide range of well established and emerging technologies like anaerobic digestion.

Because of the low population in the urban areas and presence of the isolated regions and aboriginal communities without any connection to sewer or grid, the potency for a small scale alternative decentralized system is huge in Australia especially in Victoria.

The SSAD (Small Scale Anaerobic Digestion) is a promising decentralized technology where various feedstocks are degraded in absence of O2 to generate digestate & biogas in Victoria (methane and CO2). Energy balance in such systems is helpful because biogas may be used as a renewable energy source whereas digestate may be used as an important fertilizer.  Presently, several small digesters are installed in many rural areas of India, China and several other countries. The biogas is used for cooking with use of adapted cooking stoves however several other applications like biogas mantle lamps, generators and refrigerators are becoming very common.

One more emerging technology for the small scale applications is MCHP or micro-combined heat and power device where the turbine, fuel cell or engine is used for generating heat as well as electricity. While big-scale CHP systems were used for several years, MCHP have just started to become popular but have the potency for extensive usage. This new technology usually generates between 5-20 kW. But because of the cost, they are often used in the developing nations for replacing the conventional boilers.

The combination of the above mentioned two technologies can contribute significantly to sustainable production of thermal and electrical energy in Australian households.