Energy-from-Waste (EfW) is a waste-to-energy process whereby energy is generated from the treatment of waste either to create electricity, heat or fuel.
This method of energy recovery offers two clear advantages: it reduces the amount of waste that cannot be recycled; and it recovers waste, using it to generate energy in the form of electricity, heat or fuel, and obtaining recycled materials such as compost, biochar or oil.
The process is carried out in plants that are not strictly renewable energy producers but, as they exploit the energy potential of waste, do not generate additional greenhouse gas emissions. Moreover, they can be considered unlimited energy producers given the high volume of waste that is generated worldwide. In this way, they are a real and effective alternative on the path to sustainability.
The high volume of waste generated by our societies is a growing problem. The European Commission estimates that, by 2050, we will consume as much as if we had three planets, and they also forecast a 70% increase in waste by that year.
At the same time, the need to find new sources of energy that are more efficient and less polluting has become an urgent priority. In this context, technologies such as incineration with energy recovery, gasification or anaerobic digestion are today the best alternative: methods that minimise the problem of waste and offer another solution for generating electricity, heat and fuel. Methods that are, after all, a more sustainable option than disposing of waste in a landfill.
The need to find new energy sources that are more efficient and less polluting has become an urgent priority
Boosting the circular economy
There are several ways to produce energy from waste. Energy-from-Waste plants can use different technologies depending on the type of waste to be treated, the environmental conditions or the desired end product, among other things. These technologies can be divided into two types:
The European Union is determined to commit to the energetic use of waste as part of its drive towards the circular economy. This is one of the main elements of the European Green Deal for sustainable growth, which aims to promote responsible consumption and to keep the resources used within the EU economy for as long as possible.
Among other objectives, the European Commission’s Circular Economy Action Plan aims to ensure that less waste is generated and to create an internal market for high-end secondary raw materials (those from the re-use of recovered or recycled raw materials from waste), achieving world leadership in this respect.
Despite the efforts, waste management in the EU varies between member states. In southern Europe, countries such as Spain dispose of more than half of their waste in landfills, while their northern neighbours, such as Germany and the Netherlands, do so by less than 1%. The latter, together with Sweden, Denmark and Belgium, form the group that establishes the model to be followed; where landfills are practically non-existent, waste management is focused on recycling and there is a firm commitment to energy recovery.
Therefore, we need to be able to develop and apply techniques that allow us to reduce the negative impact of waste and to exploit its full potential.
Production of renewable gases
One of the most widespread EfW technologies is anaerobic digestion, which allows waste to be converted to biogas (gaseous fuel) and digestate (fertiliser material).
This is a highly versatile waste-to-energy technology which, in addition to reducing greenhouse gas emissions, is a material recycling operation. Biogas can be used to produce electrical energy, thermal energy and fuel (biomethane) renewable with characteristics and applications similar to those of natural gas.
Biogas is one of the European Commission’s commitments to meet its climate objectives and reduce energy dependence on foreign countries. So is renewable hydrogen.
Biogas is one of the European Commission’s commitments to meet its climate objectives and reduce energy dependence on foreign countries
Green hydrogen, although obtained mainly from renewable energies such as solar power and wind power, can also be generated from waste, in which case hydrogen is obtained from the reforming of biomethane with water vapour.
This technique is similar to the production of grey or blue hydrogen from natural gas, but replaces the source fuel with biomethane. This minimises CO2 emissions, which is of great importance for decarbonising sectors such as public transport or certain industrial sectors.
Thus, both biogas and renewable hydrogen are a viable and immediate option to accelerate the energy transition. And all from waste that would be unusable in a landfill.