Technology

The Overwood Energy Recovery Facility will use moving grate technology to transform non-recyclable waste into energy and other reusable by-products.

The process involves non-recyclable waste being treated at high temperatures in carefully controlled conditions to create high pressure steam. This steam then rotates turbines at the facility to generate electricity that can be exported into the national grid.

The process creates a number of useful by-products such as heat and electricity that can be used in nearby homes and businesses (including direct connections for local businesses, where possible); and ash and metals, which can be recycled for use in construction or other products. The creation and use of these by-products mean that 100 percent of the waste treated by the ERF can be diverted away from landfill.

The ERF will transform 330,000 tonnes per annum of waste into energy. This waste would otherwise be sent to landfill or exported abroad. In 2019, Scotland sent 1.4m tonnes of non-recyclable waste to landfill.

The ERF will generate around 34.1MW of electricity of which 30.7MWe will be exported to the national grid. This is enough electricity to power around 82,200 homes, over a half of homes in South Lanarkshire (145,000 households in South Lanarkshire – https://www.southlanarkshire.gov.uk/). The ERF is designed to be ‘CHP ready’ so that heat in the form of steam or hot water could be exported to other local users in the future.

The site is expected to be connected to the 33kV network. A new substation will be constructed on the site with an underground cable connection to the existing substation at Strathaven grid supply point (GSP) located approximately 10 km North-West of the site. The Facility has already received a grid connection offer from the local distribution network operator (DNO) to connect into Strathaven GSP.

Click here to learn more about how an energy recovery facility works, or watch the video below.

ERFs in the UK

This technology is safe, environmentally sustainable and reliable and is tried and tested throughout the world. Over 1,000 energy from waste plants operate around the globe, the majority of which use mass-burn moving grate technology, including Viridor’s existing ERF at Dunbar in East Lothian.

Below you can find a map of ERFs in the UK, including those developed and operated by Viridor.

Managing Air Quality and Emissions

Technology: Modern plant technology installed will ensure that the level of emissions fall within guidelines stipulated by the Scottish Environment Protection Agency (SEPA) and will also meet air quality standards set by European and UK legislation. Flue gas cleaning technology will ensure the emissions from the Overwood ERF will be treated to ensure that emissions are abated to levels which are in accordance with the latest environmental performance standards.

Regulation: The Overwood ERF, like all modern ERF facilities, will be regulated to ensure it meets the requirements of the European and UK legislation, which is strictly monitored by Viridor and enforced by SEPA. The design and operation of all new energy recovery facilities must comply with the Emission Limit Values (ELVs) set out in the recently published Waste Incineration BAT Reference document and the Industrial Emissions Directive. The ELVs will be set at levels to minimise the impact of waste incineration on human health and the environment and ensuring the highest levels of environmental protection are applied.

Monitoring: The Scottish Environment Protection Agency (SEPA) will require that emissions are monitored to demonstrate that they are within permitted levels. Most emissions will be monitored continuously using certified and calibrated continuous monitoring systems. The continuous monitoring systems will be fed back to the ERF control room, so any potential issues are identified immediately and, if required, corrective actions can be taken. Some pollutants, such as metals, cannot be monitored continuously as they are released at very low concentrations, these will be monitored periodically by an independent certified emissions monitoring contractor.

Pollution Prevention Control Permit (PPC): The ERF will require a PPC permit, which is separate to the planning application and is issued and regulated by the SEPA. A PPC permit will impose operational controls and monitor requirements on the Facility and will only be granted if SEPA is satisfied that the operation of the Facility will not result in unacceptable impacts upon local population and the environment. Without a PPC permit, the ERF will not be able to operate.