Waste-derived energy ‘can help solve renewables intermittency’

Energy derived from waste streams has significant potential to complement power from renewable but intermittent generating sources, a new discussion paper says.

Generators powered by post-recovery wastes can be configured to provide some or all the ancillary services needed to support clean renewables (as well as balancing technologies and firming technologies), according to the Australian Council of Recycling (ACOR).

The ACOR discussion paper says that while these generators would be relatively small in the scale of the electricity system, “their ability to operate constantly and be able to provide a series of stabilising flywheels could be increasingly valuable when operating as part of high intermittent, asynchronous generation system”.

The paper finds that clean energy can be derived from organic wastes, such as food waste, biosolids, green waste, and paper and cardboard in three ways:

  • by the pre-waste collection and industrial composting of organic wastes to produce biomethane and soil improvers;
  • by the management of landfills to harvest a proportion of the methane from the decomposition of organic wastes disposed of there; and
  • by the combustion of remnant organic and other materials left in the post-recovery waste stream to create dispatchable, low-emissions electricity which can provide valuable supporting services for high intermittent renewables electricity systems.

Increasing waste-derived generating capacity could also have the added benefit of off-setting the waste levies imposed by some states, says Cameron O’Reilly, ACOR’s interim CEO.

“As the economics of recycling and resource recovery facilities are underpinned by avoided landfill levies rather than wholesale energy prices, they can be viable through periods of low or negative wholesale prices unlike some other forms of clean energy generation,” he said.

ACOR represents about 50 businesses operating in the $15 billion resource recovery industry.