How this North Salt Lake plant will turn table scraps into natural gas

The University of Notre Dame installed three Grind2Energy systems, which aims to reduce the amount of food waste from the campus’ dining halls. The systems process the waste and send it to a local dairy farm where they break down the material to produce biogas that is used to generate electrical power for 1,000 homes each day in Plymouth, Indiana. While not everyone at the university has committed to the sustainability efforts, these systems can be scaled to be used on other college campuses.

According to the United Nations, approximately 1.3 billion tons of food is wasted every year, which is costly to the environment and the economy. In Seoul, technological waste bins calculate the weight of the garbage against a set limit, and if the disposal is too heavy there is a fee. To reduce landfill deposits, Seoul has also composted food waste by turning it into animal feed, fertilizer, and electricity generation.

What started as a small group of people taking pictures of waste in their communities and tagging it on Instagram with the hashtag #Litterati, turned into a global effort, and even an app, to map and dispose of trash. Users can upload to the app an image of trash and machine-learning algorithm can tag it location, material, and company who made it. The city of San Francisco asked the makers of the app for help documenting cigarette butts and tobacco products on its streets and ended up winning a legal victory over the tobacco industry to increase the taxes on their products.

Finding ways to implement circular systems reduces the environmental impact of festivals. The London-based nonprofit, a Greener Festival, works with festival planners across Europe to make events more sustainable. In addition to recycling and moving toward plant-based food options, a Greener Festival also leverages its partnerships to collect and reuse catered food through its EighthPlate initiative.

In South Korea, a combination of grassroots movements and government campaigns have dramatically reduced the country's food waste by 95% (about 400 metric tons a day). Residents are required to buy special biodegradable bags, which serves as a tax that finances 60% of the city's food processing. It's a pay-as-you-waste tactic that also prompts citizens to find creative ways to recycle and compost, and special weighing machines encourage them to extract the moisture first, saving even more money on collection costs.

After seeing prayer flowers wasted week after week, one church in Mumbai, India, implemented a new biologically-sustainable solution. The church now creates its own biogas, reducing waste and creatively producing energy alternatives.

Rotterdam, a port city once at the center of trade and commerce, is now threatened by climate change. The city has responded to this threat by totally transforming itself into a hub for sustainable design. It embraces crazy, environmentally friendly solutions. From a floating dairy farm to a home enclosed in a greenhouse to basketball courts that soak up rainwater, Rotterdam has established itself as a leader in sustainable urban design. By 2025, the city plans to be completely climate-proof.

Loyola University Chicago's Searle Biodiesel Lab converts approximately 9,000 gallons of used cooking oil annually from campus dining halls and local institutions into 8,000 gallons of cleaner-burning biodiesel, which powers eight campus shuttle buses and produces 1,500 gallons of hand soap as a byproduct. Since 2013, the lab has created learning opportunities for students and operated as a financially self-sustaining enterprise.

Green Era's biodigester facility processes food waste in a closed, oxygen-free system that captures methane and converts it into renewable natural gas while producing compost. The system, which launched in spring 2025, accepts packaged food waste from restaurants, food banks, grocery stores, and residential composting services. The facility diverts approximately 85,000 tons of food waste annually from landfills and supplies enough renewable natural gas to Peoples Gas to power up to 3,000 homes.

Lithium-ion battery recycling, spearheaded by companies like Redwood Materials, collect and process batteries from electric vehicles and consumer electronics, recovering critical minerals and reducing reliance on damaging mining practices.