The Clean Tech Opportunity Cost of Mine Opposition

Quantifying the potential climate benefits of two stalled mines in Minnesota

The Clean Tech Opportunity Cost of Mine Opposition
A former iron mine in Minnesota's iron range. Adobe.

During the last world war, Americans intimately understood the connection between raw materials and the tools necessary for national victory. The head of an old shovel could supply the metal for four hand grenades, while a broken radiator might contain enough steel for seventeen rifles. At a strategic scale, iron mines like those of Minnesota’s Iron Range supported the production of armies’ worth of tanks and the largest naval fleet in the history of mankind.

People in Northern Minnesota have not forgotten the role that previous generations of Minnesotan miners played in fighting for a more hopeful and just world, but misguided mining opponents and anxious policymakers seem determined today to keep the state’s wealth of clean energy metals in the ground rather than putting them to work in the clean energy transition. The valuable copper and nickel contained in Minnesota’s long-stalled NewRange Copper Nickel (NewRange) and Twin Metals Minnesota (Twin Metals) mine projects—and the batteries, solar panels, and wind farms they could support—represent a missed opportunity to support climate efforts.

Assuming that even just 25% of the annual copper production from these two projects went to support either solar or wind farm construction, the cumulative emissions benefits of the resulting solar and wind capacity could be on the order of 800 to 1500 million metric tons of CO2 over a 20-year period.

For comparison, should the state achieve its 2030 target of 50% emissions cuts relative to 2005 levels and continue that pace of reductions over the following decade, cumulative Minnesota emissions from 2020-2040 would total 1800 million metric tons of CO2. This suggests that the additional climate value of the clean energy infrastructure that these two Minnesota nickel projects could support may be on the order of 40%-80% of the state’s total emissions over roughly the next twenty years.

Another 25% of annual nickel production from the NewRange and Twin Metals projects would in turn help supply roughly 2.43 million electric vehicle batteries over 20 years, adding a further emissions benefit of around 78 million metric tons of CO2.

Both copper and nickel are increasingly important clean energy minerals facing growing global demand driven not just by accelerating deployments of solar farms and batteries but also by general societal needs like wiring, electronics, and stainless steel. With opposition to mining in democratic, well-regulated countries effectively encouraging more carbon-intensive, polluting, and socially irresponsible mining overseas, American production of our fair share of energy transition copper and nickel is not only the duty of a wealthy developed nation responsible for climate change, but likely better for people and the environment.

Just as recycled shovel heads alone cannot produce an armada of ships, the energy transition cannot advance—let alone succeed—on just recycling and no new mining. Constrained supplies of copper and nickel could raise the cost of solar panels, electric cars, hydrogen electrolyzers, electric heat pumps, and numerous other technologies important for climate efforts. Policymakers should consider how they plan to meet future demand for clean energy minerals, and think deeply about how projects like NewRange and Twin Metals could help.

Figure 1: Potential cumulative avoided emissions from mining-enabled deployment of either solar, wind, or electric vehicle technologies over 20 years of mine project operation. Wind energy deployment exerts the highest impact, delivering possible climate benefits of up to 80% of Minnesota's cumulative emissions from 2020-2040
Figure 2: Minnesota’s cumulative emissions based on state climate targets over the 20-year period of interest, compared against US economy-wide emissions in 2022. A rough estimate of Minnesota’s 2020-2040 emissions assuming achievement of Minnesota’s 2030 CO2 target is around 30% of current U.S. emissions in a given year.

A tale of two long-suffering mine projects

Twin Metals

The push to develop the Twin Metals project regained speed in 2012 when Antofagasta, a mining firm, applied to renew long-idled project leases acquired from the company’s predecessor, International Nickel Company. Over ten years later, the proposed underground mine still has no clear path forward—not because of a lengthy environmental review or lawsuit, but instead because different administrations have flip-flopped back and forth on the project. Federal administrations possess unusual authority in this case because unlike most hardrock mining projects, the jurisdiction of the land Twin Metals hopes to develop falls under a lease system rather than a mining claim system. The key difference? Leases must be renewed.

The flip-flopping began under the Obama administration when it cancelled the leases in response to public pushback, citing it had discretionary authority because production had yet to begin. It then initiated a mineral estate withdrawal as a final measure to ban mining in the region for 20 years. The Trump administration declared the cancellation invalid and reversed course on both actions. The Biden administration cancelled the leases again and finally completed the withdrawal. Twin Metals is appealing the lease cancellations, but is at the mercy of administrations to revoke the withdrawal. The project could still proceed if the leases are reinstated and grandfathered into the withdrawal area, though it is not clear if it would be feasible given the added restrictions of the surrounding area.

Aside from the subjectivity of lease renewals, the timing of the withdrawal efforts suggests political motivations. Any ecological considerations of the neighboring Boundary Waters region, the risks from mineral leases like Twin Metals, and thus environmental motivations for preemptively banning mining have existed for decades. So, the decision to pursue the withdrawal in response to a specific project moving forward implies that administrations were reacting to short term public pressures. Withdrawals are a valid policy tool in principle, but, in this case, their application superseded Twin Metals’s environmental review. Therefore, what was ostensibly environmental in motivation instead excluded any determination of the project’s actual environmental risk let alone the chance to mitigate those risks through public discussion.


The NewRange project’s delays, on the other hand, originate from avoidable agency procedural failures caused by poor coordination. The project started its environmental review in 2005, with the Environmental Protection Agency (EPA) subsequently warranting a supplemental review to address potential impacts to local water quality—an understandable concern given the open pit design of the mine and its wetland environment. As the review continued in tandem with consultation from local tribes and stakeholders, NewRange addressed the EPA’s concerns and completed its review in 2016.

State and federal agencies then began granting permits for functions such as tailings dam construction or water discharge. The EPA, however, failed to meet their legal obligations to notify the Fond Du Lac Band that the Clean Water Act permit issued by the Army Corps of Engineers (ACE) in 2019 could potentially impact them. So the Fond Du Lac Band sued the EPA, which in turn urged the ACE to suspend the permit until a separate hearing could discuss the Band’s concerns. The Band argued that the water management of the project was insufficient to meet its water quality standards, which are more stringent than the state’s and a key concern given that the Band lives downstream of the site. Ultimately, the ACE revoked its permit in 2023 based on the Band’s substantive concerns.

NewRange is free to revise their plans to accommodate the Fond du Lac Band’s concerns, but cannot recoup the time lost from agency miscoordination. The EPA’s failure to notify the Band alone delayed any revisions until 2.5 years after the ACE originally issued its permit, thanks to court proceedings and agency deliberation. Furthermore, the Band was serving as a cooperating agency throughout the initial environmental review process, in which water quality concerns were well known. So one can only condemn the EPA, ACE, or state for failing to mediate these concerns in real time over the previous 15 years.

Our analytical approach

We adopted expected mine production rates for copper and nickel for the first 20 years of operation based on the production schedule presented in a for the Twin Metals project for the NewRange project, as well as estimated production rates published in a recent promotional report for the Twin Metals project. We then assume that only 25% of copper or nickel production from these projects enters clean technology supply chains—a percentage that could be much higher or lower based on market factors or direct supply agreements with downstream clean tech customers. We think of our wind copper case, our solar copper case, and our EV battery nickel case as independent scenarios, although they are not necessarily mutually exclusive in practice.

To convert these production rates into gigawatts of solar or wind capacity and units of electric vehicle batteries, we assumed a copper intensity of 2840 tons/GW for utility-scale solar PV installations and 2369 tons/GW for onshore wind facilities, based on the National Renewable Energy Laboratory’s 2023 Renewable Energy Materials Properties Database and cross-referenced against a recent Bloomberg New Energy Finance analysis in the case of solar. For electric vehicles, we assumed a nickel demand of 39 kg in the cathode active materials for a 60 kWh nickel-manganese-cobalt 811 electric car battery. (Although not considered here, such a battery would also contain 5 kg of cobalt, 5 kg of lithium, 5 kg of manganese, 20 kg of copper, and 30 kg of aluminum in its battery cell components alone, based on a 2021 European Federation for Transport and Environment report).

These assumptions yield average production equivalent to 6.46 GW/yr of solar PV, 7.75 GW/yr of onshore wind, or 122,000 electric vehicle batteries/yr. Over the hypothetical 20-year timeframe, the total production quantities result in 129 GW of solar capacity, 155 GW of wind capacity, or 2.43 million electric vehicles.

Figure 3: Cumulative quantities of solar installations, wind installations, or electric vehicles that the NewRange and Twin Metals mines could support via 25% of projected production over 20 years of operation.

For the solar/wind capacity produced from the mines’ output in each year, we calculated annual generation output assuming a solar PV capacity factor of 24.6% and a wind capacity factor of 34.6%. We calculated total generation for either the solar case or the wind case only over the 20-year period of interest, considering 20 years’ worth of electricity generation from the wind/solar units produced in the first year, 19 years of generation from units produced in the second year, and so forth.

Multiplying the total annual generation in each scenario by an assumed carbon grid intensity in that year yields the avoided emissions for each year. We scaled our carbon grid intensity assumption down from a U.S. average of 450 g CO2e/kWh to a starting assumed carbon grid intensity of 350 g CO2e per kWh to coarsely reflect embodied life-cycle emissions and lower avoided emissions in operational practice. We then assumed this value decreases further each year by 2.78% as the grid decarbonizes.

To calculate cumulative electric vehicle emissions benefits, we similarly consider only the portion of electric vehicle usage contained within the 20-year time window of interest, based on a 10-year vehicle lifespan and an assumed lifetime mileage of 180,000 miles. This is again somewhat conservative, as it only considers two years of emissions benefits from an electric vehicle produced using nickel mined in the 19th year of our calculation, for instance. We assess the relative emissions-per-mile difference of an electric vehicle versus a conventional gasoline-powered car by assuming a lifetime CO2e footprint of 152 grams-per-mile for an electric car, and a footprint of 375 grams per mile for a gasoline car. This produces a full life-cycle benefit of 40.14 tons of CO2e for our representative electric vehicle, relative to a gasoline car.

We adopt Minnesota’s aspirational emissions trajectory from 2020-2030 consistent with the state’s 2030 emissions target, then extrapolate this 2020-2030 trend to derive statewide emissions for each year between 2030-2040 and calculate cumulative expected emissions for the 20-year period. Our visualizations using this cumulative emissions figure are by no means suggesting that Minnesota should think of copper and nickel mining as an alternative to statewide emissions goals, but rather serve as a yardstick for approximating the additional decarbonization value of the NewRange and Twin Metals mines’ metal production.

Putting context to copper and nickel numbers

The material value of the NewRange and Twin Metals mines in terms of their ability to support clean technology deployment is undeniably significant.

The value of mined copper in terms of solar or wind farms could be of comparable magnitude to one-half to three-quarters of Minnesota’s future state-wide emissions (see Figure 1). In comparison, the emissions benefits of the mined nickel in electric vehicle terms is much smaller, but still respectable at 78 million metric tons of CO2 avoided over the 20-year period.

The disparity between the decarbonization value of copper from the NewRange and Twin Metals projects relative to nickel simply results from the fact that these mines would produce 6.7 tons and 4.4 tons of copper for every ton of nickel, respectively. Indeed, while many pro-development political, labor, industry, and community leaders have emphasized the climate importance of the nickel from these projects, discussions to date have perhaps understated the significance of an even larger copper story.

Environmental opponents of these projects will likely continue to argue that the particular environmental risks associated with these mines are unique, and that expected increases in global copper and nickel demand does not mean these specific projects ought to proceed.

The problem is that environmental activists take similar stances of opposition against seemingly every proposed mine project. Frequently, activist groups show disinterest in finding innovative ways to address expressed environmental concerns, preferring instead to oppose projects under any and all circumstances. In practice, this long standing dynamic has helped push mining activities into many regions and countries where environmental activists cannot operate or face intense prosecution—with predictably poor environmental, social, and climate outcomes.

Rather than force upstream mineral supply chains out of sight and out of mind, it is time for advocates and policymakers to recognize that democracy, accountability, and transparency are strengths that can help America lead by example in crafting more just clean technology supply chains. A renewed appreciation of mining and metals industries can not only help ensure secure mineral supplies for a global energy transition, but help drive progress towards decarbonizing those industries themselves. Until policymakers start thinking seriously again about how to responsibly develop new mines in the United States, the country is abdicating important responsibilities for advancing decarbonization efforts.

If federal leaders are serious about making America “the arsenal” of clean energy technologies, then it would be wise to recall that there can be no arsenals without mines.

You can find supplemental materials here and here.