As the world population continues to grow and consumption increases, waste management becomes an increasingly pressing issue. In developing countries, especially in Southeast Asia, there is a lack of proper facilities for waste disposal. Recent reports have also revealed a trend of wealthy nations shipping container loads of trash to developing countries where the situation is further exacerbated by the lack of resources and infrastructure needed to manage waste in an effective and sustainable manner.
New and innovative waste management technologies, such as waste-to-energy, are contributing to the solution by transforming waste into a valuable source of energy while reducing those that ends up in landfills. Besides mitigating the negative impacts of waste mismanagement on the environment, waste-to-energy technology could also play a part in the world’s collective green energy agenda.
One Man’s Trash
Waste-to-energy (WtE) plants use waste as a fuel source to generate electricity. The most common method used is incineration, where organic materials such as food waste, paper, and plastics, are incinerated to generate electricity. The heat produced in this process can also be used for other purposes, such as space and water heating for nearby communities, buildings and industrial processes.
The waste-to-energy cycle – how it works
Examples of WtE methods include:
Gasification: Heating waste in a low-oxygen environment to produce gases that can be used as fuel in combustion engines or burned to generate electricity.
Anaerobic digestion: Using microorganisms to break down organic waste, producing methane and carbon dioxide. The methane can be burned to generate electricity, while the carbon dioxide can be captured and used in other industrial processes.
Pyrolysis: Heating waste in the absence of oxygen to produce a synthetic gas, which can be burned to generate electricity or used as a fuel for other purposes.
While municipal solid waste is the most commonly used type of waste, agricultural waste such as crops and livestock manure, as well as industrial and medical waste can also be used to generate energy, at once alleviating the waste management and energy needs of the surrounding areas.
Although early WtE systems were criticized for their low efficiency and high environmental impact, the technology has evolved significantly over the years, becoming more efficient, environmentally friendly, and cost-effective. Newer systems are able to convert a higher percentage of waste into energy while reducing emissions through the use of advanced pollution control technologies. On top of this, by contributing to the overall energy generation, WtE also has the potential to diversify the renewable energy mix and decrease the overall reliance on fossil fuels.
Challenges in Waste-to-Energy
Despite the technology’s potential, there are several concerns surrounding the use of WtE. Modern WtE facilities can be expensive to build and upgrade, making it difficult for implementation. Additionally, if not designed and operated correctly, WtE facilities can have negative environmental impacts, such as air and water pollution, and release harmful pollutants into the atmosphere. In Europe, these overlooked factors have long been causing backlash against the region’s WtE plants, which are reported to pump out millions of tons of CO2 every year.
Another concern with implementing wide-scale WtE systems is the potential for these systems to disincentivise recycling practices. By increasing competition for the waste stream, WtE systems could pose a challenge for recycling programs to collect and process materials. This competition could ultimately lead to reduced recycling efforts and a shift towards using WtE as the primary solution for managing waste. In Britain, this is already a reality – nearly 45% of its waste is burned, more than the amount of waste that the country recycles.
Evidently, when WtE systems are seen as the primary solution for managing waste, it can lead to a decreased focus on waste reduction and recycling efforts. This can result in a lack of support for recycling programs, making it harder for these programs to operate effectively, as well as create unregulated waste trade for profiteering.
Waste-to-Energy in Action
In Europe, WtE systems are widely used, with many countries having a long history of using this technology. For example, Germany’s WtE systems have been in operation for over a century, and the country has one of the highest rates of WtE usage in the world. A closer look at the country’s WtE system shows that good planning and oversight are all that is needed to unlock the technology’s positive potential. Germany has around 68 waste incineration plants with a combined annual capacity of 20 million metric tonnes and, in 2018 alone, municipal waste incineration generated over 6100 GWh of electricity. Despite this, the recycling rate of waste in Germany remains among the highest in the world. The effectiveness of this system is largely due to the strict regulations in place that ensure WtE facilities operate in an environmentally responsible manner and the country’s investment towards advancing WtE technology to reduce emissions and increase the efficiency of WtE processes.
Over in Sweden, the past few decades have seen WtE systems evolve far beyond basic waste management. With the help of the country’s intensive recycling program, only 1% of the country’s trash is sent to landfills. For the remaining 99%, 47% is recycled and 51% is converted into energy, providing heating for a million homes and electricity for 250 thousand homes. In fact, this system is so efficient that the country imports trash and recycles the waste produced by other countries, generating a whopping USD100 million every year from this practice. As a result, the country’s carbon dioxide emissions are reduced by 2.2 million tonnes annually, its streets remain clean and the high cost of waste management is instead a profitable venture for the country.
Closer to home, with a growing population and limited land availability, Singapore has had to get creative with its waste management system. The country’s waste disposal infrastructure consists of four WtE plants where most of its waste is burned to 10% of its original volume. The residue from this process and non-incinerable waste is then shipped to the country’s only landfill. The positive effects of Singapore’s waste management system are well-known – the country is renowned for its efficiency and cleanliness, after all. However, its high reliance on incineration for waste disposal results in extremely low recycling rates and massive waste volumes for a country of its size.
Malaysia Takes Charge of its Waste
As the world’s second-largest producer of palm oil, Malaysia generates tonnes of biomass waste from palm oil extraction
As the world’s second-largest producer of palm oil, Malaysia generates tonnes of biomass waste from palm oil extraction. Much of this and other agricultural waste is incinerated or processed to produce bioenergy, which makes up around 14% of Malaysia annual energy use, and the palm oil industry, led by the Malaysian Palm Oil Certification Council (MPOCC), constantly strives to create a true circular palm oil economy. Still, only a fraction of the country’s bioenergy potential is being tapped, and with Malaysia’s commitment to its net zero emissions and zero waste goals, the country is determined to make the most of available opportunities.
In 2020, the Housing and Local Government Ministry of Malaysia (KPKT) announced plans to set up six WtE plants by 2025. The construction of the first of these plants, which became operational in Jan 2023, was monitored by foreign experts who provided similar technology to Sweden and Germany. The Malaysian government also intends to take an integrated approach to waste management, incorporating material recovery and waste treatment with the goal of treating 95% of its overall waste, and using only non-recyclable waste materials for WtE processes.
National utility, Tenaga Nasional Berhad (TNB) is also contributing to this revolution through its research arm, TNB Research (TNBR). TNBR has been tapping on local talent, such as researcher Ahmad Faizal, to experiment with green energy and waste management solutions such as turning plastic waste into green fuel through the more efficient pyrolysis process instead of incineration.
Untapped Energy Potential Awaits
Turning waste into energy has the potential to be a highly effective solution for managing waste and reducing the amount of waste sent to landfills while addressing our growing energy needs. When executed well, WtE systems can provide clean, renewable energy while also improving air quality and reducing the negative impact of waste on the environment.
From Germany to Sweden and Singapore, successful WtE systems have demonstrated the potential of this technology. However, it is important to consider the potential challenges of WtE systems and ensure that they operate strategically, in an environmentally responsible manner. Nevertheless, with the right policies and investments in advanced technology, WtE has the potential to play a significant role in the transition to a more sustainable energy future.