Reconciling waste to energy with recycling

The waste hierarchy approach prioritises recycling over waste to energy processes. Recycling is considered to be more energy efficient as waste is treated as a resource that can be re-processed, thereby reducing the need for primary processing of raw materials.

Recycling truck in Birmingham. Photo by Birmingham City Council

Recovering energy from ‘residual’ waste which cannot sensibly be recycled remains a sound environmental objective, and is supported by European legislation on waste and renewable energy.

The Renewables Obligation (RO) is currently the main market support mechanism for renewable electricity. Electricity suppliers are obliged to source a growing proportion of the electricity they supply from renewable sources (currently up to 15.4% by 2015), confirmed by Renewables Obligation Certificates (ROCs). The Renewables Obligation provides support for electricity produced from the biomass content of waste treated in gasification, pyrolysis, anaerobic digestion and good quality combined heat and power plants.

Therefore, government policy has been to promote greater energy recovery from food waste (via anaerobic digestion) and waste wood (via combustion) to capitalise on the potentially significant energy and carbon benefits.

A mix of waste treatment and energy recovery options is likely to provide the preferred solution in most areas at the regional and city scale. The choice of technology will ultimately depend on the waste stream characteristics and the specific site identified for the facility. There is potential to incorporate large-scale waste to energy plants in new site developments.

An exemplar scheme in Norway at the ENERGOS Energy from Waste Plant in Stavanger is an example of a waste to energy plant which has been incorporated into the town’s suburbs. It is a gasification plant which relies on the non-recyclable content of the town’s waste stream and has illustrated how a smaller scheme footprint can economically be developed to serve a town the equivalent size to Reading.

A common concern is that the investment needed to build an energy from waste facility can become a disincentive to recycle. However, many European countries have shown that a vigorous waste to energy policy is compatible with achieving high recycling rates. Germany and the Netherlands both exemplify this trend. For example, Germany manages 20% of waste via waste to energy methods, but also sees 26% of waste recycled and 10% composted.

Priority: turn waste into energy
Tags: energy, waste, regions and subregions, cities and towns, neighbourhoods