Energy from waste: A solution in the waiting

Sir: In the last three weeks, I have attended five workshops and stakeholder events around power generation in Nigeria. Unfortunately, none discussed the potential for energy recovery from waste in Nigeria.

Global estimates indicates that about 70% of solid waste generated is disposed in dumpsites and landfills with 19% ecovered through recycling or composting and the remaining 11%converted to energy, using different energy recovery technologies.

In Nigeria, over 90% of non-metallic solid waste collected ends up in unsanitary dumpsite. As frequent as possible, these dumpsites are set on fire to reduce the volume of waste; disrupting ambient air quality and releasing dioxins, furan, VOCs, PCBs etc. and heavy metals like Mercury and Lead. These pollutants have long-term health consequencesincluding cancer; liver problems and impairment of the immune system. In addition, the biodegradable fraction of waste forms leachate which seeps into and contaminates ground water.

Furthermore, data shows that the disposal of large amounts of waste in landfills and dumpsites accounts for about 5 per cent of total global greenhouse gas (GHG) emissions and 12 per cent of the world’s methane (CH4) emissions; a GHG that is 23 times more potent than carbon dioxide (CO2).

Thus, with waste generation projected to increase with growing population and changing consumption patterns in Nigeria, current poor waste management practices can only translate to more environmental and health challenges.

But thanks to science, there are technological options available to minimize aftermath release of pollutants and GHG emissions from waste. These include recycling, composting and energy recovery. The latter being focus of this piece.

Energy recovery otherwise called Energy-from-Waste (EfW) or Waste-to-Energy (WtE) involves the combustion of waste in a controlled chamber to produce electricity and/or heat. Energy from waste technology reduces the overall GHG emissions by as much as 80% in comparison to waste disposal in dumpsites and reduces to the barest minimum release of pollutants. In fact efficient energy recovery is considered as recycling.

Global EfW market is projected to grow by about 50% from 25.3 billion in 2013 to US$37.6 billion by 2020. In 2015, it was estimated that the over 2,200 energy from waste plants across the worldprocessed about 280 million tonnes of waste, a45% increase from 2010 estimates of about 192 milliontonnes processed.

Countries like Sweden, France, Denmark, Netherlands, Switzerland, and Japan currently incinerates (for energy production) over 50% of solid waste that is not recycled, thus, reducing the amount of waste that ends up in landfills to as low as 4% of the total waste generated.

Emmanuel Unaegbu, Renewable Energy and Environmental Protection Expert writes from Abuja