Getting to Net Zero Carbon Emissions – and Even Net Negative – Is Surprisingly Feasible and Affordable

Net Zero Carbon Emissions 2050

Regardless of the pathway we take to become carbon neutral by 2050, the actions needed in the next 10 years are the same. Credit: Jenny Nuss/Berkeley Lab

New analysis provides detailed blueprint for the U.S. to become carbon neutral by 2050.

Reaching zero net emissions of carbon dioxide from energy and industry by 2050 can be accomplished by rebuilding U.S. energy infrastructure to run primarily on renewable energy, at a net cost of about $1 per person per day, according to new research published by the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), the University of San Francisco (USF), and the consulting firm Evolved Energy Research.

The researchers created a detailed model of the entire U.S. energy and industrial system to produce the first detailed, peer-reviewed study of how to achieve carbon-neutrality by 2050. According to the Intergovernmental Panel on Climate Change (IPCC), the world must reach zero net CO2 emissions by mid-century in order to limit global warming to 1.5 degrees Celsius and avoid the most dangerous impacts of climate change.

The researchers developed multiple feasible technology pathways that differ widely in remaining fossil fuel use, land use, consumer adoption, nuclear energy, and bio-based fuels use but share a key set of strategies. “By methodically increasing energy efficiency, switching to electric technologies, utilizing clean electricity (especially wind and solar power), and deploying a small amount of carbon capture technology, the United States can reach zero emissions,” the authors write in “Carbon Neutral Pathways for the United States,” published recently in the scientific journal AGU Advances.

Transforming the infrastructure

“The decarbonization of the U.S. energy system is fundamentally an infrastructure transformation,” said Berkeley Lab senior scientist Margaret Torn, one of the study’s lead authors. “It means that by 2050 we need to build many gigawatts of wind and solar power plants, new transmission lines, a fleet of electric cars and light trucks, millions of heat pumps to replace conventional furnaces and water heaters, and more energy-efficient buildings – while continuing to research and innovate new technologies.”

In this transition, very little infrastructure would need “early retirement,” or replacement before the end of its economic life. “No one is asking consumers to switch out their brand-new car for an electric vehicle,” Torn said. “The point is that efficient, low-carbon technologies need to be used when it comes time to replace the current equipment.”

The pathways studied have net costs ranging from 0.2% to 1.2% of GDP, with higher costs resulting from certain tradeoffs, such as limiting the amount of land given to solar and wind farms. In the lowest-cost pathways, about 90% of electricity generation comes from wind and solar. One scenario showed that the U.S. can meet all its energy needs with 100% renewable energy (solar, wind, and bioenergy), but it would cost more and require greater land use.

Carbon Neutral Infrastructure Transition

In the least-cost scenario to achieve net zero emissions of CO2 by 2050, wind, solar, and battery storage capacity will have to increase several-fold (left chart). Vehicles will need to be mostly electric, powered either by batteries or fuel cells (middle charts). Residential space and water heaters will also need to be electrified, powered either by heat pumps or electric heaters (right charts). Credit: Williams, et al., 2021

“We were pleasantly surprised that the cost of the transformation is lower now than in similar studies we did five years ago, even though this achieves much more ambitious carbon reduction,” said Torn. “The main reason is that the cost of wind and solar power and batteries for electric vehicles have declined faster than expected.”

The scenarios were generated using new energy models complete with details of both energy consumption and production – such as the entire U.S. building stock, vehicle fleet, power plants, and more – for 16 geographic regions in the U.S. Costs were calculated using projections for fossil fuel and renewable energy prices from DOE Annual Energy Outlook and the NREL Annual Technology Baseline report.

The cost figures would be lower still if they included the economic and climate benefits of decarbonizing our energy systems. For example, less reliance on oil will mean less money spent on oil and less economic uncertainty due to oil price fluctuations. Climate benefits include the avoided impacts of climate change, such as extreme droughts and hurricanes, avoided air and water pollution from fossil fuel combustion, and improved public health.

The economic costs of the scenarios are almost exclusively capital costs from building new infrastructure. But Torn points out there is an economic upside to that spending: “All that infrastructure build equates to jobs, and potentially jobs in the U.S., as opposed to sending money overseas to buy oil from other countries. There’s no question that there will need to be a well-thought-out economic transition strategy for fossil fuel-based industries and communities, but there’s also no question that there are a lot of jobs in building a low-carbon economy.”

The next 10 years

An important finding of this study is that the actions required in the next 10 years are similar regardless of long-term differences between pathways. In the near term, we need to increase generation and transmission of renewable energy, make sure all new infrastructure, such as cars and buildings, are low carbon, and maintain current natural gas capacity for now for reliability.

“This is a very important finding. We don’t need to have a big battle now over questions like the near-term construction of nuclear power plants, because new nuclear is not required in the next ten years to be on a net-zero emissions path. Instead, we should make policy to drive the steps that we know are required now, while accelerating R&D and further developing our options for the choices we must make starting in the 2030s,” said study lead author Jim Williams, associate professor of Energy Systems Management at USF and a Berkeley Lab affiliate scientist.

The net negative case

Another important achievement of this study is that it’s the first published work to give a detailed roadmap of how the U.S. energy and industrial system can become a source of negative CO2 emissions by mid-century, meaning more carbon dioxide is taken out of the atmosphere than added.

According to the study, with higher levels of carbon capture, biofuels, and electric fuels, the U.S. energy and industrial system could be “net negative” to the tune of 500 million metric tons of CO2 removed from the atmosphere each year. (This would require more electricity generation, land use, and interstate transmission to achieve.) The authors calculated the cost of this net negative pathway to be 0.6% of GDP – only slightly higher than the main carbon-neutral pathway cost of 0.4% of GDP. “This is affordable to society just on energy grounds alone,” Williams said.

When combined with increasing CO2 uptake by the land, mainly by changing agricultural and forest management practices, the researchers calculated that the net negative emissions scenario would put the U.S. on track with a global trajectory to reduce atmospheric CO2 concentrations to 350 parts per million (ppm) at some distance in the future. The 350 ppm endpoint of this global trajectory has been described by many scientists as what would be needed to stabilize the climate at levels similar to pre-industrial times.

Reference: “Carbon‐Neutral Pathways for the United States” by James H. Williams, Ryan A. Jones, Ben Haley, Gabe Kwok, Jeremy Hargreaves, Jamil Farbes and Margaret S. Torn, 14 January 2021, AGU Advances.
DOI: 10.1029/2020AV000284

The study was supported in part by the Sustainable Development Solutions Network, an initiative of the United Nations.

10 Comments on "Getting to Net Zero Carbon Emissions – and Even Net Negative – Is Surprisingly Feasible and Affordable"

  1. The article speaks to costs in dollars to ramp-up significant changes in infrastructure. However, the point of the exercise is to reduce CO2! What appears to be missing from the analysis is the ‘cost’ in increased CO2 emissions during the build-out phase resulting from mining, processing, fabricating, and transporting the materials needed to replace existing power sources. There is also no mention of the esthetic and economic costs of modifying huge areas of land to support low energy-density sources like PV panels and wind turbines, and the associated transmission lines. It strikes me that high-density sources like nuclear or thermonuclear would have less impact on the land.

    Batteries for EVs will put a severe strain on the available resources for elements like cobalt. The ‘woke’ illiterati are even now complaining about its production by artisanal miners, using child labor. It is inevitable that the cost of cobalt, and subsequently the batteries, will increase. Wind turbines require Rare Earths, currently monopolized by China. If they would even sell us the quantities needed, the price could become prohibitive. I wonder if this was considered?

    The authors promote increased use of heat pumps. For starters, their efficiency declines with cold weather (as do EV batteries), and they can become parasitic, resistive loads and contribute to bringing down the grid during cold snaps, while providing no benefit to the owners. Not everyone either has enough land, soil deep enough, or unobstructed access to the field to install the piping. Then, there is the cost of installation and maintenance!

    Lastly, it seems that the report was written before the Texas debacle of February 2021 and the lessons learned about the tradeoffs with reliability by relying on so-called sustainable energy.

  2. The USA can’t stop Climate Change alone. Only China, India, etc., can stop climate Change. And they aren’t going to cooperate. Its not the technical problem. Rather, its the political problem. Changing the selfish behavior of 7 billion people, increasing to 10 billion people, and the politics of 100 Nations to stop climate change would to be a miracle, even Bill Gates has said so. China is going to pursue Chairman Xi`s dreams. India is going to build housing, provide electricity, and air conditioning to their billion. And the worlds population and consumption is increasing. A Malthusian Collapse is far more probable that stopping climate change

  3. So many elephants in the room

    Total US annual energy use is 100XJ or about 96Quads for BTU people.

    Per capita US energy use is 10KW of primary energy or 300GJ/yr. One 250W PV panel makes only 1GJe yr in the US NE with battery backup for daily cycle.

    Search “Energy Flow Graph LLNL”, and “Per Capita Energy use” on Wikipedia, and read the David MacKay book, “without the hot air”.

    These folk don’t seem to understand some basic physics. You must have storage in the system, either upfront in fossil fuel, hydro, or uranium inputs which is trivial to store and then convert to electricity at desired rate. Typically 1gal of fuel is 30KWhr of chemical energy equivalent to 10KWhr(e) costs maybe $1 per gallon to store so 10c/KWh(e) but storage is completely in front of generation.

    Or you start with completely intermittent electrical inputs and then try to store maybe half of that in electric batteries after generation, so $400/kWh in a Li ion battery which is 4000 times that of chemical storage. For uranium, the ratio is in the billions. Or if you don’t want to store electrical energy, you just use natural gas on demand for backup and stay dependent on fossil fuels, something like 70% fossil with 30% intermittents and the CO2 elephant is ignored.

    Or you convert electrical to chemical and back to electrical for round trip efficiency of maybe 15%. That forces energy production inputs of intermittents to be increased at least 50% or more so energy can be stored over months. The issue of losses for chemical to electricity conversion seems terrible to greens but they completely miss it when they think of 2 conversions for free in a bid for the pure electric economy. They are smitten with the fantasy of an Apple, Tesla wonder world where new technology has almost no new energy inputs. When steel is replaced with aluminum for electric car bodies, the energy content is 6 times greater. It is almost certain that any electric car has at least 50% more energy invested in it. A VW gas car has about 50k miles on the odometer for energy inputs when new i.e. 17MWhr. Will Tesla tell us what a Model 3 energy content is?

    The US Navy did a research project to extract CO2 from the oceans, the best place to scrub CO2. The electrical energy needed to remove ocean CO2 is exactly the same as the energy gained when the CO2 was first released from the fossil emitting power plant decades before. Can anyone see this elephant in the room, methane and coal was converted to useless CO2 and later recovered with no net energy produced.

    If we had 1000GWe of totally clean energy to replace the current 3000GW of primary energy use, we would need to triple that for the next 50 years to offset the last 100years of 50ppm CO2 increase using the entire excess 2000GWe just to get the old CO2 out of the system. If there is a more efficient CO2 scrubbing process than the Navy project, I’m sure they would like to know what they got wrong. Everyone will have to get onboard, more trees will help a bit.

    We should be looking at Molten Salt and Sodium cooled reactors. Moltex has a design they claim can be built for $1B at 1GWe scale vs the usual $5B for PWRs. The reason is simple, it has no pressure in the coolant loop and fully decouples the NRC regulated nuclear heat plant from the generators which can drive the grid at perhaps 0.3GWe to 3GWe until the daily heat pool is used up. It would mostly be running near 1GWe to match the 2GWth produced. The reactor building is about 50x smaller than a conventional PWR building since it needs no containment.

    Around 800 of these Moltex plants replacing all US fossil energy and most intermittents would remove the CO2 and battery problem in a stroke for perhaps $800B. Most of them wouldn’t even make electricity, instead they would make hydrogen for synfuels.

    A 2GWth MSR could produce hydrogen at 1GW of hydrogen power with the catalytic S-I process replacing S-I chemical plants for generators for about $1B. With PV electrolysis, it would be more like $100B assuming the input is constant power but I can only find 1KWe electrolyzers for cost comparison.

    The nuclear hydrogen program would be near 100% capacity factor plants. The Solar or Wind hydrogen plants would be the same capacity factor as the energy sourced or much worse. If energy is used for the grid first, when in demand, then excess energy has an even lower capacity. For a mostly solar grid, about 1/2 of all summer solar could go to hydrogen production, perhaps in winter it might run in reverse if fuel cells are used.

    These catalysts cost resp per ton, Sulfur $50, Iodine at $26K, Platinum $40M.

    And finally think of the eWaste, about 8% of the US land surface covered with low energy density hardware that lasts maybe 15-25 years while 800 MSRs would be all but invisible.

    Personally I don’t expect the country go this way because AOC and her kind have no clue about electrical engineering or basic science.

    • “These catalysts cost resp per ton, Sulfur $50, Iodine at $26K, Platinum $40M.”

      These different catalysts require different amounts to work properly. I think that it would be more objective to normalize the requirements in terms of $/kw-hrs or installation, rather than $/ton.

      • You are correct, I don’t have access to the internal designs and costs of said electrolyzer using platinum, or S-I chemical reactors for nuclear heat to know how much catalyst they each need for similar hydrogen output, but platinum is still 2000 times the price of iodine. I would love to see the cost projections of such plants at the same scale though. I know the Chinese LFTR/TMSR project is developing the S-I procees but starts with nat gas instead of MSR heat.

      • I forgot, the overriding factor is that a dedicated high temp MSR reactor with an S-I chemical plant will be near 100% capacity factor, while solar or wind with excess peak energy picking will mean extremely low capacity factor, all that platinum will be mostly idle year round, less idle if it battery buffered first. I’m sure the future hydrogen plant designers would choose the much higher capacity design in a heartbeat.

  4. John Jakson, the elephant in the room may be you. Many fine suggestions toward solving the problem, but shooting barbs at the people actively trying to help the situation is usually a typical cynical and unhelpful American elephant idiosyncrasy. Are you actively helping, or just bloviating more greenhouse gas?

    • Of course I am cynical, we have some great and very mature technologies available that can provide base load power and they are all nuclear based. No need to develop vast scale batteries for this.

      At the same time the folks that love solar and wind and dismiss nuclear are chasing their tails after magical new battery technologies to avoid looking at nuclear but are quite happy to use nat gas for buffering, so only giving a small reduction in CO2 but an unknown amount of methane leaks that probably cancels any advantage over coal.

      We only have to look at the massive elephant in Germany, they shut down half their nuclear fleet and went full on brown coal to buffer intermittent energy. The CO2 emmisions never went down, all the CO2 savings they claim from solar, wind were taken away from nuclear. I hear they just had a “conversation” about this, they might yet decide not to shut down their remaining reactors which Angela Merkel promised a decade ago to do in 2022.

      Here in MA, we are looking forward to losing the last nuclear plant left in NE, by folks that will switch it for nat gas because the Dems can not accept science in engineering. The local fancy folks MA Sudbury have road signs that say no new powerlines for no growth, so much for the all electric economy.

      California is doing the same, gov Newsom has said as much, CA will be nuclear free by 2024

      You bet I’m mad as hell. My 3 daugters in college have no idea what is coming to them by 2050 when climate change really clobbers the whole system.

      Here is another wierd thing about coal, of course it’s a bad source of energy for so many reasons, but as soon as we shut it down, the sulphates it emits will quickly stop covering up half the CO2 warming we should have seen already.

      When ordinary Texas folks don’t seem to know how to turn off the water mains in their homes, how on earth can they be expected to know anything about energy policy.

      I’m not the elephant in the room, I’m the invisible mouse.

      The elephants in the room are the dems shutting down nuclear and the gop dissing climate change and the green activists that didn’t take science or math classes, a pox on all of their houses.

      So as a fellow engineer, what solution are you offering?

      • John
        You remarked, “When ordinary Texas folks don’t seem to know how to turn off the water mains …”

        From what I have read, when some of the communities went to smart water meters as a way of encouraging saving (?) water, some bureaucrat decided that access to the meters and valves should be locked to protect the expensive electronics. So, it was the fault of someone who had an inability to think outside the box and was focused on costs. However, the common impression held by many, that children in the future would not know what snow was like, may have contributed to downplaying the risk of future cold weather.

        You also said, “My 3 daugters in college have no idea what is coming to them by 2050 when climate change really clobbers the whole system.” I think that you are overly pessimistic. We are constantly bombarded by apocalyptic forecasts from the Media and well-meaning, but overly excitable, young scientists. The science behind such concerns is rather poor. Simplistically, all the Global Circulation Models (GCM) run warm, and present us with an average when the bulk of the historical increases are at night and in the Winter. The models are claimed to be based on physical principles. However, they are ‘tuned’ to the past using fudge factors, hoping that the forecasts will then be correct. If one starts with an equation that is correct, but then adds a factor that is subjective, then it is no longer based on physical principals! Clouds cannot be handled at the spatial resolution of the GCMs, so they are ‘parameterized.’ That means that the GCMs have a model embedded in them that is the best guess of the behavior of energy exchanges taking place in the clouds. I could go on easily for an hour to bend your ear because there are so many problems with the modeling. Because you are an engineer, I would strongly encourage you to do a ‘deep dive’ into the issues because most of them are beyond the ability of the typical person to understand. Perhaps one of the key issues is that when even peer-reviewed research is published, the authors often leave out error bars on their numbers and carry more significant figures than are warranted. Until recently, NASA was publishing tables of monthly ‘anomalies’ with three significant figures to the right of the decimal point, when the original data was typically no better than 0.1 deg F. They rationalize that with several excuses, such as the Law of Large Numbers, that don’t hold up to scrutiny. It is generally accepted in metrology and statistics that the standard deviation can be reduced in proportion to the square root of the number of readings. That addresses random measurement errors. However, that requires taking many readings at a weather station when the temperature varies with every little gust of wind. Thus, there is only one chance to take a reading at a particular time. Furthermore, it requires that all global readings be taken with the same calibrated instrument. If you really dig into this, you will discover that the “king has no clothes.”

        • We obviously seem to agree on energy policies and thats what matters most, nuclear energy at base loads means potentially low energy prices no matter the weather conditions and higher quality of life for all as well as taking out fossil fuel polution besides CO2.

          We can disagree on climate modelling though, but in the 20 years of retiring in MA, the snow levels have dropped greatly year on year with occasional reminders of the stuff.

          Actually the 3 girls 2050 remark alarmism is mainly focussed on a German style energy policy coming our way where energy starvation will be very real for poor folks, when the cost of each KWhr will be $1 or more most of the time when the sun don’t shine and wind don’t blow. Energy storage on the grid side of the eqn is 1000s times the storage at front before the energy source is used. And ofcoure Germany never saw the CO2 reduction they were promised.

          The king has no clothes remark really and very obviously applies to all the non engineers trying to make the RE model work, it’s even worse when many educated climate scientists get out of their expertise area and jump on RE. I am all in with James Hanson on this, and if we go full nuclear, it doesn’t matter diddly squat if we are wrong on CC.

          regards

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