Unpacking the PUC’s recent decision on the carbon free standard

The Minnesota Public Utilities Commission's recent vote on Minnesota’s Carbon Free law may have opened the door to allowing technologies that are not good for the climate to qualify as “carbon-free.” But what does that really mean? And what happens next?

A satellite view of North America on October 7, 2024, showing wildfire smoke from the west snaking across the middle of the continent, and a Category 5 Hurricane Milton churning in the Gulf of Mexico. (Image credit: Cooperative Institute for Research in the Atmosphere, Colorado State University) 

The climate emergency is real, and swift action to reduce our climate pollution is needed. That’s why the Minnesota Legislature passed the 100% clean energy law in 2023. We don’t have to speculate on whether the climate emergency is happening, we can see it with our eyes and smell it with our nose. The rapid intensification of Hurricane Milton over the record-hot waters of the Gulf of Mexico and the multiple years of widespread wildfires across the western U.S. and western Canada are just two recent examples of how the climate crisis is at our doorstep. 

That’s why MCEA is focused on the fastest possible adoption of carbon-free electricity under the 100% law. We simply don’t have time or money for false climate solutions. On September 26, the Minnesota Public Utilities Commission issued a decision on the implementation of the 100% law that may have opened the door to allowing technologies that are not good for the climate to qualify as “carbon-free,” particularly the burning of trash and biomass to generate electricity, even though both emit large amounts of carbon dioxide. 

This piece answers some of the questions we’ve heard from supporters and members about the decision:

What was the Public Utilities Commission (PUC) deciding, and what was MCEA’s position? 

The issue in front of the PUC in September was to consider how to define “carbon-free” under the 100% carbon-free law passed by the Legislature in 2023.    

MCEA, representing itself and the Sierra Club, took the position that the carbon-free definition is clear and unambiguous. That’s because the law plainly states: “‘[c]arbon-free means a technology that generates electricity without emitting carbon dioxide.” That means that generating technologies that do emit carbon dioxide, like burning biomass or trash, should not be considered carbon-free.  

The PUC was also asked to determine how to assign partial compliance credit under the law for electricity generated from a  facility that uses “carbon-free technologies,” but only “for the percentage that is carbon free.”  The legislative history makes clear this section of the law was intended for technologies that reduce overall carbon emissions attributable to a power plant, such as by co-firing with green hydrogen or adding carbon-capture technology. 

We should note that MCEA has significant doubts that green hydrogen and carbon-capture will ever be good climate solutions. These are simply the technologies this part of the law was intended to apply to.  MCEA argued that partial credit should be limited to technologies like these which, if fully employed at a power plant, could theoretically yield generation that is carbon-free as defined by the law, and not for technologies like burning trash and biomass, which can never yield carbon-free generation. 

What did opponents argue?

A powerful group of opponents (including the forest products industry, some local governments, the Department of Commerce, the Minnesota Pollution Control Agency, and many utilities) argued for far looser definitions of carbon-free. They claimed that generation from burning woody biomass and generation from burning trash should both be considered partially or even fully carbon-free, despite the fact that both emit a significant amount of carbon dioxide. 

The forest products industry argued that the carbon dioxide emitted from burning woody biomass should be considered carbon free because it originally comes from trees, and as trees regrow in the decades ahead they will reabsorb the carbon dioxide.  In other words, they said the process is “carbon neutral.” Even if the law allowed “carbon neutral” technologies rather than requiring carbon-free ones, the math still doesn’t pencil out.  Woody biomass facilities emit on average twice as much carbon dioxide per unit of electricity as a coal plant, and some emit four or five times more. In fact, studies show it would take decades of increased tree growth (i.e. planting of trees above and beyond current levels)  to offset a biomass facility’s high emissions just to get the plant to be on par with a coal plant’s emissions. We don’t have that much time to address the climate crisis. In addition, the assertion that burning biomass is carbon neutral relies on the assumption that when biomass is burned for power, someone will plant more trees than they currently are and that will offset the emissions from this one plant.  We think that’s wishful thinking. And those burning the woody biomass typically have no obligation to plant new trees, much less protect them for the decades it would take to reabsorb the carbon emitted by the plant.

Our opponents also argued that if woody biomass waste – such as industrial waste from paper mills and the branches leftover from logging  –  isn’t burned to make electricity, it would just be left on the ground to rot, releasing the same carbon dioxide, or it would be landfilled, creating methane, a more potent greenhouse gas.  Even if this was a relevant consideration under the law, this claim assumes that the climate-damaging waste management practices of the past will never be improved upon.  In fact, if we are to achieve our statutory goal of net-zero greenhouse gas emissions economy-wide by 2050, the forest products industry – like all industries – will have to find ways to actually reduce its carbon emissions.  For example, waste wood could be composted or turned into biochar, or the industrial practices could be changed to reduce the amount of waste biomass created in the first place.  

Trash incineration also has an extremely high carbon intensity.  A national study found these facilities emitted 1.7 times as much carbon dioxide per unit of electricity as a coal plant.  But proponents of trash incineration argued, like the forest industry with its own waste, that if they did not burn the trash, it would be landfilled, causing methane emissions  This either-or argument was explicitly rejected by the chief House author during the legislative debate, who stressed the need for more recycling, composting, and waste reduction.  Many communities have already committed to advancing these cleaner approaches to waste management to protect our air and water; doing so is also critical to protect our climate. 

What was the decision of the PUC with regard to biomass and trash burning?

The PUC’s decision is complicated. Instead of simply deciding that burning biomass or trash do or do not qualify under the law, commissioners decided that both could qualify as carbon-free if they emit fewer greenhouse gasses than alternative means of handling the waste in question, such as landfilling. What share of the technologies’ generation can be considered carbon-free will depend on a “life-cycle analysis,” with the more detailed requirements for such analyses to be decided in additional proceedings. Commissioners also decided that the amount of credit each technology will receive will be based not on its carbon dioxide emissions, but rather on how it compares to the carbon footprint of other waste disposal methods, and possibly on a consideration of future forest regrowth. 

This goes well beyond most life-cycle analyses. Such analyses typically consider a facility’s direct emissions and some share of the emissions related to its supply chain, but they do not then offset those emissions by considering other emissions that “might have been” under other scenarios.   

Comparing waste incineration to landfills - the worst and least controlled waste disposal method available - misses the point. Curbing the climate crisis and reaching our goal of net zero emissions economy-wide by 2050 requires innovation and progress in every sector that currently emits greenhouse gasses, including waste management and the forest products industry. It’s a false dichotomy to tell the public we have to allow trash and biomass incineration under our new carbon free law simply because landfilling releases greenhouse gasses. There are many other options, including more composting of organics, more recycling, and more innovation around reducing the amount of waste created in the first place. 

What happens next?

First, the PUC has to issue a written order summarizing the actions taken at the September 26th meeting. Then, once the PUC issues a written order, parties can ask the PUC for reconsideration of their decision. If the PUC’s decision stands, it will begin a year-long process of establishing the requirements for investigating the “life cycle” of various qualifying fuel sources, including trash and biomass. 

In other words, the decision in September is not the final word on what the 100% clean energy law means, or how the PUC will apply it to specific facilities. 

We’re on the case

The passage of the 100% carbon-free law was an important moment in Minnesota’s efforts to address the climate crisis. But the law itself is not a panacea for decarbonizing the energy sector - how it is interpreted and implemented will require ongoing advocacy. This docket is the first of many ways special interests are going to try and work around the requirements of the law. Today, burning biomass and trash are  very small overall contributors to our electric grid or to greenhouse gas pollution. But as we have seen elsewhere (such as in the European Union), biomass can become a major loophole in efforts to reduce greenhouse gas pollution from electricity. And both biomass and trash burning emit dangerous air pollutants, beyond greenhouse gasses, that impact nearby communities. 

MCEA is paying attention, and we will keep you informed as Minnesota develops the infrastructure to ensure that our electricity is 100% carbon-free by 2040, as the law requires.