An Opportunity for Cambodia!
Written by Leif Holmberg
Waste to Energy is an efficient way of using resources, ensuring that when a material can no longer be recycled into new products, we make use of the energy content, and thereby also reducing the need of other sources of energy. Energy production always comes with environmental impacts, in particular fossil fuels, but also renewable energy production requires construction material so energy efficiency and the efficient use of resources is a target for every country.

There are many forms of waste to energy opportunities, most commonly dry waste composed of a mix of wood, plastic, dry organic matter. This is incinerated to generate heat and electricity. The most important limitation for waste to energy is scale and investment cost. The incinerator must be big enough and equipped with air pollution control devices to ensure incineration temperature is high enough to destroy all potential harmful air pollutants such as dioxins and furans. An efficient waste to energy plant should operate above 1100 degrees Celsius. Waste (incineration) to Energy is an interesting technology but comes with environmental risks. Not managed well, it just transforms the waste pollution on land and in water to air pollution, potentially equally harmful for the environment. This means that small scale waste to energy units tends to come with risks of higher air pollution since it is harder to reach high incineration temperature in smaller units. UNDP supports the ministry of environment to develop technical guidelines for waste incineration that can be developed into regulation.
Another form of waste to energy is bio-digestion. The technology means that organic waste is pumped into a digester where organic substances are broken down by microbes in an oxygen free environment (Anaerobic digestion, AD) producing methane gas. The biogas can be used as fuel directly, be cleaned to same quality as natural gas or used to produce electricity. Compared to other technologies, AD is a fully enclosed system and all biogas could be collected which helps to reduce environmental impact and GHG (greenhouse gas) emissions. Biogas production can be based on residual resources such as organic waste, sludge from wastewater plants, industrial waste from slaughterhouses and food processing etc. Besides producing energy, it also produces compost or bio-fertilizer closing the ecological loop and contributing to circular economy. UNDP support the government to develop a strategy for circular economy, this includes promotion of 4R: Reduce, Reuse, Recycle and Recover and policy development for waste management.