Solar Sensors Monitor Atmospheric Carbon

Experts at the Queensland University of Technology (QUT) are the proud owners of a new sensor station that can easily monitor carbon dioxide concentrations in the air above the QUT Gardens Point.

The entirely solar-powered station can measure concentrations of atmospheric CO2, and draw daily charts describing its evolution. The studies are being carried out in real-time, the team explains.

This station was installed at the university as part of an international study on solar-powered environmental nano sensors, and is only the first in a large-scale network. The purpose of this grid is to analyze concentrations of thee main pollutants.

These are nitrogen dioxide (NO2), which is produced by engines and combustion, nitrous oxide (N2O) and ammonia (NH3), which originates in manure and fertilizers. Keeping track of how these substances spread through the air is vital for refining current climate models.

QUT School of Engineering systems master student Alexander Malaver says that the solar-powered sensor with is now operational at the university is a prototype for other similar devices to follow.

“These gases are not commonly studied because they are found in low concentrations in the environment but nitrous oxide and ammonia are more polluting than carbon dioxide, and we are developing new cheap sensors able to detect them,” Malaver explains.

“The aim of this research is to be able to let people know in real time the concentration of these gases around roads and farms so that they can change their behavior if necessary,” he goes on to say.

“Also when we know the concentrations we can find out if these gases are harmful to humans or affect only global warming,” Malaver believes. He adds that a future network of such sensors would communicate wirelessly among themselves, and also to a central monitoring station.

The sensors themselves are powered by dye sensitized solar cells, and are made up of carbon nanotubes and metal oxide nanowires. They are relatively cheap to manufacture, and provide great cost-benefit.

“This form of solar power is ideal for this project because it costs less than conventional silicon-based technology and has less embodied energy in its manufacture. It also produces electricity more efficiently in low light conditions,” the QUT expert concludes.