Drones could provide a cost-effective method for measuring methane fluxes from landfills, according to a study commissioned by the Environment Agency (EA).

Over the course of an eight-month investigation, scientists from the Centre for Atmospheric Science and the School of Mechanical, Aerospace and Civil Engineering at the University of Manchester have been developing a method to quantify whole site methane emissions from landfills using drone technology, also known as unmanned aerial systems (UAS).

According to the EA, 830,000 tonnes of methane is thought to be produced by the UK waste sector a year. The project has been developed to find more accurate ways to measure emissions from landfill. Currently, landfill emission figures are calculated by scaling up informed estimates about how much certain sources emit, rather than through measurements quantifying the actual level of gas being emitted.

Following a feasibility study on remote sensor technology and the requirements of Civil Aviation Authority (CAA) regulations governing flights by unmanned aircraft, the project considered and developed both rotary and fixed-wing UAS devices to test data collection systems.

The first consisted of a six-rotored drone with a tethered sampling line to create vertical profiles of methane and carbon dioxide. The other device was a fixed-wing, electrically-powered aircraft with an onboard ‘high-precision carbon dioxide infrared reference cell’. No high-precision methane instrument is currently suitable for flying on a small UAS, though the project expects such instruments to become available in the near future.

Both UAS platforms were tested through 10 days of field work. Using the two drones, researchers were able to map the levels of carbon dioxide and methane above selected landfill sites showing variations in altitude and location on the site.

Despite the report confirming the potential of the project to provide a cost-effective way of monitoring landfill emissions, further work is needed, say project managers, to improve UAS software and hardware systems.

This is not the first example of the EA developing unmanned drone technology, with the regulator’s Greater Manchester, Merseyside and Cheshire enforcement team trialling the use of a remote controlled aerial imagery reconnaissance (AIR) unit to scout for signs of fire in waste sites.

Potential of waste emissions improvement highlighted

The report’s publication comes on the first day of the 21st session of the Conference of the Parties (COP21), which will see representatives from more than 190 countries convene in Paris to discuss a new global agreement on climate change.

A report created ahead of the conference by Eunomia Research and Consulting on behalf of Zero Waste Europe, Zero Waste France and ACR+ has highlighted the role that better waste management could play in reducing emissions in Europe.

According to the report, EU emissions could be cut by around 200 million tonnes of CO2 equivalent a year by 2030 if best waste practices were adopted across the union.

However, the report also states that these benefits are not being communicated due to misleading statistical groupings in the United Nations’ emissions inventory. It warns that there is a risk that governments and international bodies may overlook waste management’s potential contribution to decreased emissions, though it is, the report contends, one of the simplest ways for them to be cut.

You can read more about the use of drones in waste management in our cover feature from Resource 81.