Turning Food Waste into Fossil-Free Fuel: Innovative Solutions to Complex Challenges

One of the primary goals of the National Grid Partners Innovation team is to encourage new technologies and business models that can support renewable energy and set us on the path to net-zero emissions.

“Achieving those objectives requires us to think holistically, clearly, and critically about doing things in a different way,” said Sander Cohan, who led the project as NGP’s Head of US Innovation.

NGP knows downstate New York is a critical market where innovative solutions can help address the needs of National Grid customers, while also delivering on our fossil-free gas commitment. It’s an area with significant demand for energy, where local carbon emissions laws also require customers to manage their food waste. In NY this amounts to almost 3.9 metric tons of uneaten food goes to landfills or incinerators each year.

That presented the Innovation team with an ideal opportunity to test distributed, localized technology that will allow the generation of renewable energy at the customer level.

“The idea was: What if we can make renewable energy where the customer needs it, rather than having to ship it all over the country and all over the world?” Cohan said. “What technologies can help us meet this challenge and meet this need?”

With this goal in mind, the Innovation team hit on a creative way to create renewable natural gas using anaerobic digestion.

How It Works

Anaerobic digestion is a process—similar to a cow’s stomach—that turns organic waste into fertilizer and methane, which can be converted into energy. For biogas production, colonies of bacteria in sealed containers break down the organic matter, and the waste gas captured is transported via pipe and can be used to generate electricity and/or heat. Most commercial digesters are currently installed on farms and at landfills, where large amounts of waste are centralized in a single location. These digesters are massive in size and cost millions of dollars to construct and install, making them impractical for widespread use in urban areas like New York City.

To address these challenges, NGP is working with a Seattle-based company, Impact Bioenergy, which manufactures portable bioenergy systems that fit inside a shipping container. The smaller size drives down costs and makes it easy to deliver and install the units wherever they might be useful.

These bioenergy systems can reduce the environmental footprint of even a single cafeteria or restaurant by creating a circular economy in which waste, fuel, fertilizer, and food don’t have to be trucked from one community to another. Instead, recycling organic materials allows communities to create renewable energy locally. Multiple bioenergy units can also be linked together to expand the capacity of the system.

National Grid is currently looking for two pilot sites – one in New York and one in Massachusetts – to develop the proof of concept.

“This is like rooftop solar for the gas business,” said Arnaldo Arnal, who developed the business case as part of NGP’s Innovation team and is now working to deploy similar pilots as part of National Grid’s Customer organization. “Imagine people generating their own gas and electricity. In the future, everyone could have a small digester like this in their home.”

Leading the Way and Delivering Impact

Conversations around climate change and the need to achieve net zero have taken on a new sense of urgency, particularly in the wake of last fall’s COP27 United Nations climate conference. That’s heightened the need for creative technological solutions.

NGP sees localized bioenergy systems as part of a constellation of technologies that can help reduce our reliance on fossil fuels. It’s not a silver bullet, but rather part of a “silver buckshot” approach in which various energy sources work together. By applying technology and smart business innovation, NGP is showing it’s possible to generate and harness renewable energy in a secure and distributed way.

Ultimately, National Grid and NGP believe this technology can provide renewable natural gas to tens of thousands of customers—the equivalent of taking hundreds of thousands of vehicles off the roads.

“We see the possibility of this scaling and delivering benefits to customers throughout our network,” said Helen Burt, Chief Customer Officer at National Grid. “It can provide extra flexibility for our gas distribution system and give our customers extra tools they didn’t have before to produce renewable energy from food waste.”