The council tried to turn dumb bins into smart ones, but it didn’t work very well

Over six months last year, Dublin City Council trialled sensors on street bins across the city centre, which could flag to council staff when the bins were almost full.

Council staff had hoped to slash how far staff had to travel around by a third, reducing carbon emissions, and saving staff the time checking bins that didn’t need to be emptied, said Barry Woods, a senior engineer with Dublin City Council.

But the trial found the tech didn’t achieve that. The design of Dublin’s bins doesn’t suit the device, and there were connectivity and battery-life issues, according to a council report.

The same sensor is used in bins in Madrid and San Francisco, but it just wasn’t compatible with Dublin’s litter bins, said Woods.

The council is still open to exploring smarter bins, he told counillors at a meeting of the Climate Action, Environment and Energy Strategic Policy Committee on 31 January.

“We are not giving up on this technology but any other product we trial in this space has to be fit for purpose for that standard public litter bin that we have in Dublin City,” he said.

Looking for better

Dublin City Council has around 3,300 bins on the streets of the city.

About 380 of those are solar-powered smart bins throwing out real-time notifications to council staff by email when they are full.

This works quite well so the council decided to look at ways to convert standard bins to smart bins, says a report to councillors on the committee.

They decided to trial sensors, the report says, to understand what they could do and how suitable they were.

Sensors would remotely ping council staff to tell them whether a bin needed emptying, saving staff from visiting bins that weren’t full yet, said Woods, when he launched the project in December 2022.

The council piloted a sensor, used in other cities, which is designed by the Danish company Nordsense, says Woods.

It started the trial early in 2023, fixing sensors to around 130 litter bins in the city centre, and training staff, says the report.

They did some tweaking of sensors and how staff emptied the bins between January and May as data came in, the report says.

Several problems cropped up with the technology and the type of litter bin, said Woods at the meeting.

Sensors had to be installed off-centre in bins with ashtrays so that they faced the bin at an angle, he said. In some bins, chutes along the side got in the way too.

Also, “The platform wasn’t able to send automatic email notifications back to the crew and this was something that was needed,” says Woods. Instead, the council had to filter the routes and print off reports to give to staff members, the report says.

The platform worked on 2G and had connectivity issues, said Woods, and the batteries quickly ran out too. At the end of the six month trial, 75 percent of the sensors had suffered battery issues, says the report.

Roar Bolt-Hansen, chief commercial officer with Nordsense, the company that makes the sensors, says that when the trial began in 2023, the device was not compatible with 4G in Ireland, but it is now.

He says the connectivity issues also arose because the bins being used were made of cast iron, which made it harder to establish a connection, and this also drained the batteries.

At the same time, the company did get a batch of faulty batteries, he says. “The faulty batteries were replaced with new sensors during the project but typically battery life for the sensors is between 3 to 5 years,” he said by email.

The council also requested reports four times a day, whereas the company recommends once per day, says Bolt-Hansen, which was also a drain on the batteries.

The council report says that despite findings looking positive at first, the limitations of the technology meant the cost of rolling it out wouldn’t be justified.

The technology has merits but the product trialled didn’t work well, said Woods. The council may look into other options in the future, he said.

When it announced the pilot in December 2022, Dublin City Council wouldn’t answer a question about the cost of the technology, saying that it was commercially sensitive.

[UPDATE: This article was updated at 13.43 on 7 February 2024 to correct an editing error, and make it clear that the tech not working on Dublin’s bins was a finding of the trial, rather than the trial flopping.]