Food waste is a major problem in the developed world. People new to buying organic food are annoyed at how quickly it spoils but what if that wilted brown lettuce could be converted into energy?

Anaerobic digestion hasn't been done on a large scale, the numbers don't work, but academics say it could. In a numerical model. The authors looked at supply chain logistics - potential sites, transportation, production, and facility costs, as well as revenue and return on investments.

Anaerobic digestion is a biological process that decomposes organic feedstock using rich organic materials such as wastewater sludge, animal manure, or yard waste. The resulting methane can be used to produce electricity, which can be transported to consumers via regional power grids. The process also yields additional bioproducts, including biofertilizer and animal bedding materials that can be sold to agricultural producers.

Their simulation leads them to believe that installing anaerobic co-digesters at wastewater treatment plants with a total annual capacity of 9.3 million metric tons could generate an 8.3% return on investment while reducing carbon dioxide by approximately one million metric tons annually. The most significant factors influencing the results were capital investment, operational cost, and tipping price, which is a service charge for waste disposal.

It sounds great, and the private sector would have done it if it were true. In California, politicians listened to academic studies claiming composting would save money and emissions, and are now $5 billion in the red due to the costs of sorting and shipping garbage. Emissions have gone up due to the energy needed for rapid composting. For methane from food waste to work there needs to be a plant every 10 miles, and in states like Illinois, California, or New York, environmental lawsuits will prevent that from happening.

Companies know that even if academics create a closed system for their models. Government would have to prop up the industry the way they do solar and wind, and with high inflation and an economy teetering on recession government can't waste any more money.