Science Library - free educational site

Waste, the new energy source

A policy to combat climate change can be partially met by utilising the energy content of waste.

Germany, Austria and Switzerland lead the way in utilising waste resources efficiently. They provide models for the integration of waste management policies with other targets, such as greenhouse gas emission reductions, and energy security.

Die thermische Abfallbehandlungsanlage kann 260 Tausend Tonnen Abfall verbrennen um 60 MW Wärme in das Fernwärmenetz ein
Spittelau Waste Incineration Plant, Vienna, 1987 facade by Friedensreich Hundertwasser

Yet many countries have very low rates of energy recovery. In part this is due to lack of infrastructure (segregated collection facilities and waste-to-energy incinerator plant), and in part this is due to the shortsightedness of policy-makers. The unpredictability of supply and price of fossil fuel can be hedged by the option to extract energy from waste. Countries like the USA, which rely on economic criteria almost exclusively, have created an enormous liability in lack of development, not only of infrastructure, but critically of public participation. The habit of throwing all waste together for landfilling will take many years of public awareness campaigns to change.

Waste Incineration Plant waste transport claw. A typical large incinerator can process around 600 tonnes a day of mixed waste.

A distinction is usually made between reutilising a product (e.g. multi-use milk bottles) for the same purpose, and reutilising the individual materials from discarded products. The material collected from domestic and commercial waste, such as glass, metal and paper, can be reused for the same purpose (e.g. newspapers), or the material can be cleaned, purified, reprocessed, and used for an alternative purpose (e.g. PVC from bottles can be used to make polyester jumpers).

In the past, policies have relied on free-market instruments. This leads to inefficiencies in recovery of usable materials from waste, and have failed to develop long-term strategies which take into account changing market conditions. Policies based primarily on the cost of recycling versus the current price of virgin material have obstructed many countries from developing the know-how and infrastructure necessary to adapt to rapidly changing demands.

The failure of free-market forces to instil sound practices in efficient resource exploitation can be corrected most directly by legislation. The support for legislation to correct single-parameter economics is fundamentally public sensitivity to the broader issues. Without grassroot support, the issues become subject to the pingpong of populist political debates, and deflate the global nature of the issues to a local agenda, usually fears of unemployment and other local economic interests. When the issues are handled scientifically and on a national or global level, they may extend the waste resource debate to climate change policies, supply security, and responsible and timely development of alternatives. The instruments available to policy-makers include limited-term subsidies for alternative technologies, fees for disposal of waste, non-fossil obligations (quotas for renewables, etc.), fuel taxes, and bans on certain options for waste management. An example of the latter is the prohibition in Germany on landfilling biodegradable substances.

Müllverbrennungsanlage Vorschubrost
The moving grate enables the movement of up to 35 tonnes of waste per hour through the combustion chamber, optimising complete combustion.

The 2013 report released by the EEA, Managing municipal solid waste, 2013 — a review of achievements in 32 European countries, reveals that where these policies have been implemented, they have a clear positive impact on waste management performance, and have a high level of acceptance by the populace as a whole. All the targets of GHG emission reduction, protection of the environment, public health safety, and a rigorous net-benefit economic environment, of which the waste management industry is an active contributor, can be demonstrated to have been achieved, or exceeded, by these policies in Germany, Austria and Switzerland. Other European countries have been much slower in enacting these policies, and are now paying the economic price, and increasing their liabilities as the world moves towards less-favourable future market conditions.

Another good reason to have a progressive waste management policy is to prevent future shortages of valuable materials. By using the current market price for virgin material as the benchmark for whether these materials should be recovered from waste, results too often in this resource being lost to landfill. Metals which are not recovered from electronic scrap, for example, not only are lost as a resource, but risk entering the ecosystem and creating a long-term environmental hazard, with related externalised and future costs. Germany is currently making efforts to recover precious metals from electronic scrap, even though the current market price makes it cheaper for manufacturers to import fresh material.

Article by Andrew Bone, December 31, 2015

News Articles

Physics News

Other News