Recyclers across the U.S. are struggling, hurt by a shortage of workers and rising costs that too often make recycling uneconomic. They are hoping, writes The Wall Street Journal (Nov. 9, 2023), that artificial intelligence can help turn things around and boost recycling rates.
How can AI help? By doing the sorting work that a dwindling number of people want to do—and doing it better. AI-driven robots pick up recyclable trash at around 80 pieces a minute; people can sort 50-80 pieces a minute. Optical sorters, a more established technology that’s growing more efficient thanks to improved AI, are much faster, sorting up to 1,000 pieces a minute.
Staffing shortages mean sorting sites can’t operate at full capacity. (Sites are often only 80% staffed and sometimes as little as 20%). In the long run, sorting machines are cheaper than human labor. Recyclers typically recoup their investment in robotic systems in two years. Around 32% of the sorting centers in the U.S. are now using robotics, up from less than 5% in 2019.
Optical sorting machines are in most of the large facilities. They use sensors and lights to rapidly find what is recyclable on a conveyor belt of mixed materials. When recyclable materials are identified, the machines fire a burst of compressed air at them to sort them into bins.
Waste Management, the biggest recycler in the U.S., is betting on AI as part of its goal to boost its recovery of recyclable materials 60% by 2030. It is investing $1 billion in recycling infrastructure including 40 recycling centers through 2026, with a big portion going to automation and AI. An automated WM plant has 4-6 people sorting along with the machines, compared with 50 employees at a nonautomated facility.
Republic Services, the second-biggest waste-and-recycling company, is investing in robots as part of its goal to recycle 40% more key materials by 2030, including cardboard, metal, paper and plastics. The company plans to have robotics at 20% of its 74 sorting centers in 2024, up from 10% today.
Still, AI brings its own challenges. Robots require upfront spending and equipment that needs frequent maintenance and upgrades. The cost for a single robot ranges from $150,000 to $300,000. Building or upgrading a recycling center around optical sorters is even more expensive than robots. Optical sorting systems cost $1-2 million each.
Classroom discussion questions:
- Recycling of municipal solid wastes has actually dropped in recent years. Why?
- What are the advantages and disadvantages of AI in this field?