MN PUC ponders the meaning of “carbon-free”

Will wood make the carbon-free cut?

As the Minnesota Public Utilities Commission (MPUC) works to implement the state’s mandate for 100 percent carbon-free electricity by 2040, many questions must be answered along the way.

On Thursday, the Commission took up the threshold question of “what is ‘carbon-free’?” The answer is of far more than mere academic interest. The answer will impact all electric utilities in the state and will make or break a number of alternative energy industries.

The statute passed in 2023 is of limited assistance, Minnesota Statutes 216B.1691 Subd. 1(b) currently reads,

(b) “Carbon-free” means a technology that generates electricity without emitting carbon dioxide.

Simple enough, or is it? The commission staff briefing papers explaining all the implications of the question runs to 104 pages.

The MPUC docket on this question drew initial comments from 52 institutions, mostly utilities, environmental nonprofits, and renewable energy concerns. 26 filed reply comments. That doesn’t include the hundreds of public comments.

Energy sources under consideration included the following,

Apparently, No. 6 is not a joke. Commission staff explain (p. 42),

What did the Commission make of all this? Walker Orenstein at the Minnesota Star Tribune reports,

Minnesota regulators on Thursday said burning wood or trash to generate electricity could be considered carbon-free under the state’s landmark 2040 climate law, depending on how emissions are counted.

So, burning carbon (wood, C + O₂ = CO₂) could be considered “carbon-free,” depending on the timeline considered.

We are just getting started on this question of how many carbon atoms (atomic number 6) can dance on the head of a pin.

Orenstein reports that carbon capture technologies may be eligible for partial credit under the law.

Next year, the Commission will take up the issue of under what circumstance (high prices, system reliability, etc.) the carbon-free mandate can be suspended or delayed.

The lives of millions hang in the balance.