Australian researchers develop sensors to monitor hay bales

Pushing a crowbar into a hay bale to test its temperature might be replaced with a more effective method of determining whether or not fodder is at risk of spontaneous combustion.

Moisture in the bales, sugar levels in the hay, aeration and temperature are all factors that contribute to fires, but how they interact to cause spontaneous combustion is not fully understood.

Researchers from Charles Sturt University have begun equipping bales near Wagga Wagga, in southern New South Wales, with monitoring equipment to understand how blazes happen and how farmers can reduce the risk.

The hay industry, from export hay to drought reserves, was worth about 2.5 billion, according to lead researcher John Broster.

If one percent of that is lost to spontaneous combustion, that's $25 million, plus the impact on the farmer and property, Broster said.

It can be very devastating if they lose their crop, they lose income, they lose infrastructure.

Broster and his team attached sensors to a stack and burnt it to mimic an arson attack.

They collected data on how the fire spread, so they could compare it to spontaneous combustion in other bales they were monitoring.

The temperature is a symptom of what is going on with the moisture and its interaction with the sugars, Broster said.

He wanted to test where to place the sensors that measured temperature inside the bale.

The researchers and their partners said they hoped to roll out smaller sensors to farmers that would monitor temperature and report back to the farmers' mobile phones.

When their stack reaches a certain temperature, an alert will be sent to the farmer, according to Broster.

If we can understand that and get a farmer to adopt it under Australian conditions, that will mean they'll have more accurate warnings of the potential for a stack to spontaneously combust, and they'll be able to manage it. Myriota will connect the sensors to their satellite system so alerts can be sent despite poor mobile coverage in rural Australia.

Myriota representative Paul Sheridan said haystack fires happened in remote locations where there was normally no mobile phone connectivity.

Farmers around Australia are hoping that sensors can be placed into their bales to monitor whole stacks and warehouses for the risk of spontaneous combustion once it is connected to the satellite system.