The energy content of waste is of the same order of magnitude as that of brown coal. Despite the separate collection of recoverable materials, residual waste still contains enough substances that can be used energetically. Energetic recycling of waste means that the energy content is used to generate electricity or heat if required.
In Germany, waste incineration systems also have to fulfil the principles of the Recycling and Waste Management Act (KrW-/AbfG):
- Avoidance (priority)
- Recycling (materially, energetically)
- Disposal (last option)
Waste treatment takes place simultaneous and in parallel to energetic utilisation. Only about 250 kg of reaction-neutral slag remains from one metric ton of this high-energy combustible material. It is often used nowadays to spare natural resources like gravel for road construction work. Another application is the use of slag as equalising material for dump sealing.
Production of Own Energy Requirement
Waste burns independently, which means that, apart from ignition, no further primary energy sources such as gas, petroleum or coal are required. More energy is in fact produced and recovered by the combustion process than is consumed. And: waste incineration plants generate their own energy, because part of the power generated is used for the plant's own requirements. This is an additional contribution to more efficient handling of energy resources.
Using alternative energy sources and implementing economic and energy-efficient technologies is becoming very important in times of increasingly scarce fossil resources. The energetic content of waste makes it an important energy carrier.
Important factors are of course plant size and waste throughput: at Helmstedt for instance, up to 105,000 households can be supplied with electricity.