Mars, industrial giants advocate new carbon math for renewable thermal

A large thermal power plant.

A decade ago, when Mars Inc. doubled down on embracing sustainable business practices, the greenhouse gas (GHG) emissions related to its electricity load accounted for about 61 percent of the company’s operational carbon footprint.

The remaining 39 percent came from its thermal loads: primarily the fuel used for running boilers to process food or sterilizing and cleaning, estimated Kevin Rabinovitch, vice president of sustainability for Mars.  

Today, through a combination of energy efficiency measures and a sophisticated clean power procurement program, Mars has removed more than half of the footprint associated with its electric load. But its progress on the thermal side has been minimal: a mere 1 percent reduction, thanks to discrete investments at some of its factories, Rabinovitch estimated.

That gap underscores a dilemma for renewables-friendly companies, particularly those with manufacturing or industrial facilities: In order to meet aggressive greenhouse gas emissions reduction targets, they need to step up investments in thermal options.

Consider that industrial heat applications account for almost two-thirds of global industrial energy demand and a large majority of the sector’s emissions, according to data from the International Energy Agency. Demand for renewable thermal energy grew at an annual rate of about 2.3 percent between 2007 and 2014, the IEA figured. In comparison, the growth rate for renewable electricity resources was about 6 percent.

"We want the renewable thermal [growth] curve to look like the electrical [growth] curve," Rabinovitch said.

One big challenge in getting there, however, is how to justify and account for the impact of renewable thermal options — such as biomass systems, ground source heat pumps or recovered heat — on carbon emissions.

"Without clarity about the impacts of different thermal energy projects, due in large part to inconsistency in the way companies are calculating emissions, this sector is lagging in deploying new purchasing options," said Bryn Baker, deputy director of renewable energy at WWF.

Here’s the problem: While the methods of "accounting" for switching to solar or wind power largely have become standardized, the same cannot be said of the thermal world. The process is especially complicated when any options being considered uses bioenergy such as wood waste or industrial residues. That raises all sorts of questions, such as: How much better from an emissions standpoint, for example, is a biomass system if it causes deforestation? How should land use factor into the equation?

"The only way we can progress is by solving for this," Rabinovitch said.

The quest for a standardized methodology was one underlying motivation for the creation last year of the Renewable Thermal Collaborative (RTC), an initiative that is part of the Renewable Energy Buyers Alliance. Mars is a member of the collaborative, alongside Cargill, General Motors, Kimberly-Clark, P&G, L’Oreal and the city of Philadelphia. The group is facilitated by the World Wildlife Fund, the Center for Climate and Energy Solutions and David Gardiner and Associates.

Its first "deliverable" is a new report that recommends ways to standardize the methodologies for six types of projects: wood chips from virgin forests; wood chips from forestry residue; wood chips from industrial residues; biomethane; heat from the ground; and recovered heat. (The title is "Renewable Heating and Cooling for Industrial Applications: Guidance for Carbon Accounting (PDF)."

Again, the biggest controversy surrounds bioenergy projects, because there is no commonly accepted standard. The most comprehensive approach for calculating their impact today is the BioGrace-II methodology, developed in Europe.

"The debate is primarily focused on the combustion of virgin wood, rather than wood wastes or residues," said Jeroen De Beer, associate director for Navigant, which produced the RTC report. "We therefore recommend that companies take a precautionary approach in their use of biomass and utilize wood wastes for renewable heating and cooling."

For ground source heat pumps and recovered heat, the analysis recommends using the widely used GHG Protocol for keeping an inventory of emissions — and commonly used by companies that report their sustainability metrics to CDP — to account for impact.

Where do things go from here?

Bryn Baker, deputy director of renewable energy at WWF, said the group’s focus in coming months will center on how to consider land use changes. The Intergovernmental Panel on Climate Change (IPCC) is set to issue updated, high-level guidance on this area by 2019. That should help the sector move one step closer to consensus.

"The list of who needs this is much longer than the list of people that realize they need this," Rabinovitch said. "There are a lot of people who haven’t quite appreciated how important this issue is."