3 reasons why environmentalists can cheer the launch of the Petra Nova CCS project

Earlier this week, the energy company, NRG, announced that its CO2 capture and storage (CCS) project at a coal-fired power plant in Texas had begun commercial operation. If history is any guide, many environmental groups are likely to dismiss this CCS project as an environmental distraction (see Greenpeace, for example). But there are a number of reasons why even the staunchest environmental advocates can applaud this project as a critical stepping stone to solving the climate challenge.

Here’s the context:

NRG has partnered with JX Nippon and the US Department of Energy to fund their “Petra Nova” project: a retrofit of NRG’s “WA Parish” coal-fired power plant outside of Houston, Texas with a post-combustion CO2 capture and storage (CCS) system. The CCS technology installed on this power plant will separate and compress CO2 from 240 MWs worth of the plant’s exhaust stream. NRG will then pipe that compressed CO2 80 miles to an oil field, where the CO2 will be injected into an old oil reservoir. The pressure from the injected CO2 will breathe new life into that oil field by pushing oil to the surface for collection. The injected CO2 then will take the oil’s place trapped in the rock below, where it will slowly mineralize into rock itself over the course of millennia. At the end of this process, would-be CO2 emissions from the coal power plants are trapped underground, resulting in a large reduction in the power plant's impact to the climate.

 Above: diagram of the oil recovery + CO2 sequestration process employed by the Petra Nova project.  Source: US DOE

Above: diagram of the oil recovery + CO2 sequestration process employed by the Petra Nova project. Source: US DOE

The Petra Nova project (and CCS technology more generally) won’t come without challenges in the future, and it is far from a long-term “silver bullet” solution to climate change that will enable us to continue the widespread use of fossil fuels indefinitely. But this project and ones like it are very valuable for the fight against climate change.  

Here are three reasons why environmentalists concerned about climate change can support CCS projects like Petra Nova:

1. CCS projects like Petra Nova can enable a cost-effective, fast, and fair transition to a decarbonized economy, but NOT to an indefinite future of expanding “clean coal” power generation. The fact of the matter is that there is a lot of existing coal power around the world whose CO2 emissions needed to be eliminated as soon as possible if we want to meet climate goals. To accomplish this feat, we have two options: 1) shut down coal power plants before their useful lives are up, and/or 2) install CCS and let these power plants continue to use coal -- but with a fraction of the climate impact -- until they become obsolete. While coal retirement campaigns like the Sierra Club’s Beyond Coal campaign have gained some traction with the first approaches, there is still a massive amount of work to be done to eliminate CO2 emissions from coal power plants across the globe. This is not to say that environmental campaigners should ditch all existing efforts around closing coal power plants in favor of advocacy for CCS -- instead, CCS can provide another valuable option for which these campaigners can advocate in contexts where the rapid shutdown of coal is undesirable and/or politically infeasible.

And how can environmental advocates trust that advocacy for CCS is actually a bridge to a coal-free future and not an indefinite license to burn coal? For one, natural gas is beating out coal as the most economically viable fossil fuel for power generation in North America, and renewables -- even when coupled with demand side management tools (e.g. battery storage, load response) -- are getting effective enough to compete against coal for new power plant capacity around the world. As President Obama recently noted in his article in Science, “the irreversible momentum of clean energy” will be difficult to overcome -- it just might take a while for this momentum to build to the point where the discussion on clean v. dirty energy is moot due to the favorable economics of clean energy alone. As a result, CCS projects like Petra Nova offer a potential lifesaver for the planet in the interim.

2. The technology pioneered at the Petra Nova project is relevant for controlling emissions from other types of fossil power generation (e.g. natural gas) and from other difficult-to-decarbonize heavy industrial sources (like cement, steel, and chemical factories). While CO2 emissions from coal power plants is a significant part of the climate problem, we will also need to eliminate CO2 emissions from other sources within the next few decades to meet climate targets. Transitioning all of these projects to renewables will be even harder than the transition from coal power, which means that CCS technology will be highly valuable for reducing CO2 emissions from these projects in the near future. Because CCS technology like that deployed at Petra Nova can be adapted for CCS at other industrial sources of CO2, projects like Petra Nova can generate valuable lessons that help us reduce costs, develop fair environmental and safety regulations, and increase investor experience for CCS projects in all sectors of the economy in the future.

  Box 4.1 of the US Midcentury Deep Decarbonization  Strategy makes it clear how important CCS is beyond coal power.

Box 4.1 of the US Midcentury Deep Decarbonization Strategy makes it clear how important CCS is beyond coal power.

3. Fossil CCS projects -- even those that use captured CO2 to produce oil -- can help pave the way for negative emissions in the industrial sector in the future. As the former NASA scientist Jim Hansen recently told Rolling Stone: “We are at the point now where if you want to stabilize the Earth's energy balance, which is nominally what you would need to do to stabilize climate, you would need to reduce emissions several percent a year, and you would need to suck 100 gigatons of CO2 out of the atmosphere, which is more than you could get from reforestation and improved agricultural practices.” The implication: in addition to rapid reductions in CO2 emissions from fossil fuel use, we’ll likely need big industrial CCS processes to generate negative emissions via approaches like sustainable bioenergy coupled with CCS and/or direct air capture (DAC) + sequestration to make our climate goals a reality. Because there are no good markets for these industrial negative emissions projects today, the only viable way for companies to develop and test the components for these solutions today is through CCS projects like Petra Nova (e.g. on a coal power plant with the CO2 utilized to drill for more oil). Is coal power for oil production a good long-term vision for CCS technology? No. But until better markets and regulations exist for negative emission technologies, these types of projects are the only viable way to improve negative emissions technology components in the meantime. 

In conclusion:

At the end of the day, the Petra Nova CCS project offers an all-too-rare example where environmentalists can genuinely applaud big energy companies for developing and deploying tools for the climate solution toolkit. CCS doesn't need to be the long-term climate solution of choice for environmentalists, but efforts like Petra Nova can be commended by all for advancing technology that will be extremely valuable in the fight to solve the climate challenge.


NGO Spotlight: Bellona

Here at the Center for Carbon Removal, it is Bioenergy with Carbon Capture and Storage (Bio-CCS) theme month, so we are particularly excited to turn our spotlight on EU-based NGO Bellona. Bellona has been a leader in the Bio-CCS field for many years -- what follows is a recap of an email exchange with Bellona Bio-CCS expert Marika Andersen to share more about their work and their views of the importance of Bio-CCS in meeting climate goals. 

Q: Who is Bellona?

A: Bellona is an independent non-profit organization that aims to meet and fight the climate challenges, through identifying and implementing sustainable environmental solutions. Our slogan sums up our optimism: From Pollution to Solution! Bellona is engaged in a broad spectrum of current national and international environmental questions and issues around the world. Our area of expertise is broad, and the staff is comprised of individuals with a wide range of professional backgrounds. With close to three decades of experience, we have established a unique network both nationally and internationally.

Q: Why is Bellona interested in Bio-CCS?

A: The scale of the climate change challenge requires that we roll-out all available solutions, including Bio-CCS. Limiting global warming to 2°C will require a tremendous effort in transforming the economy into a low carbon economy. This can only happen quickly enough through a combination of an unprecedented increase in energy efficiency, massive deployment of renewable energy technologies, accelerated deployment of CCS and application of Bio-CCS to achieve carbon negative emissions. The use of sustainable biomass in a plant fitted with CCS produces a double climate benefit that we cannot afford to ignore: Emissions from combustion of fossil fuels are prevented from entering the atmosphere and the CO2 contained in the biomass is captured, thereby removing CO2 from the atmosphere. The Intergovernmental Panel on Climate Change 5th Assessment Report is clear that the need for Bio-CCS will only increase the longer we wait to take action: “Delayed mitigation further increases the dependence on the full availability of mitigation options, especially on CDR [Carbon Dioxide Removal] technologies such as BECCS [BioEnergy with CCS]” (IPCC, 2014).

Q: What do you see as the biggest challenges to getting Bio-CCS off the ground?

A: The technical solutions for Bio-CCS exist. The challenges are on the one hand, making the political and industrial decision-making process on CCS more efficient, and on the other hand, to re-build confidence in sustainable biomass production and use. Bellona is involved in developing the sustainable biomass component of Bio-CCS, especially focusing on advanced sources that do not compete with land and food, such as the integrated solutions presented by Ocean Forest and Sahara Forest Project. Regarding CCS roll-out, it’s important to note that Bio-CCS is in many ways a low-hanging CCS fruit: The cost of CO2 capture from biofuel production such as ethanol fermentation, is generally very low, as the CO2 by-product streams are often of high purity. The pure stream of CO2 negates the need for additional separation equipment, with only driers and compression units necessary to prepare the CO2 for transport to a storage site. And speaking of storage: This is the linchpin of both fossil and Bio-CCS. Without storage capacity, capture is futile. This is why Bellona is also working to speed-up storage site development.  

Q: What is the outlook in the EU for Bio-CCS over the next few years?

A: In Europe, upheavals in the energy system caused by expansion in renewables and outdated business models, coupled with concerns about energy security, have led to renewed emphasis on the role of fossil power and CCS. On the matter of energy security, Bellona is clear that any enhanced use of indigenous fossil resources must be coupled with CCS and that opportunities for Bio-CCS must be scoped out. But of perhaps greatest importance, is the current lack of incentives to apply CCS to biomass facilities. This is because the EU focus remains on zero, not negative, emissions. As biomass is already counted as carbon neutral in the EU Emission Trading System (ETS), there is no incentive for someone using biomass to add CCS and bring their emissions below zero. A debate on reform of the EU ETS is due to begin in 2016. Bellona has already published some ideas on rewarding negative emissions in the EU ETS and will engage in this debate.  

Q: What are you planning to do at COP21 to raise awareness for Bio-CCS?

A: Bellona will be heavily present at COP21 with a pavilion that we have named Action Through Connection and are hosting jointly with the Norwegian climate research institute CICERO. Here we will host a number of events and gatherings throughout the two weeks, including two events specifically addressing Bio-CCS. The first will address why the world’s foremost climate scientists agree on the need for Bio-CCS, while the second will aim to place Bio-CCS in perspective with other carbon removal technologies and ask what we can do to get the roll-out of this vital climate technology to move faster.

Q: What publications have you released about this topic?

A: Bellona led the work of the Joint Task Force Bio-CCS of the Commission’s Technology Platforms for CCS and biofuels, ZEP and EBTP respectively, to develop a report on the Bio-CCS potential of Europe – Biomass with CO2 Capture and Storage (Bio-CCS), the way forward for Europe. Furthermore, Bellona’s CCS Roadmap for Romania – Our future is carbon negative: A CCS roadmap for Romania – addresses the country’s carbon negative potential. In the lead-up to the EU’s debate on reform of its Emission Trading System, we have released a short brief on incentivizing negative emissions – BellonaBrief: The Carbon Negative Solution – Incentivising Bio-CCS in Europe


Thanks again Marika and the Bellona EU team!

Recap: 6th Carbon Sequestration Leadership Forum Ministerial Meeting

The Center for Carbon Removal just returned from presenting at the Carbon Sequestration Leadership Forum (CSLF) Ministerial meetings in Riyadh. We went to the meetings to encourage the CSLF members to widen their focus to include carbon removal. In the process we got great feedback and learned a lot of interesting things about the state of the carbon capture and storage (CCS) field. The recap below delves into the key details and takeaways from the meetings.

What is the CSLF?

The Carbon Sequestration Leadership Forum (CSLF) is a consortium of energy ministers from 25 (mostly developed) nations, and a group of stakeholders that includes energy-focused companies and NGOs. The CSLF’s mission is to foster the development of carbon capture and storage (CCS) technologies for the energy and industrial sector—that is, technologies that separate CO2 from the exhaust streams of power plants and other manufacturing facilities, and then store the resulting CO2 deep underground in impermeable rock formations. The CSLF’s technical and policy working groups meet semi-annually to share best practices and develop recommendations for energy ministers, who gather every two years to share updates. The US chairs the Forum, and has played a large role in the organization since its formation in 2003.


What was the CSLF meeting that just took place from Nov. 1-5 in Riyadh?

The Riyadh meetings were the 6th ministerial-level gathering of the CSLF, bringing in high-ranking energy and climate change officials from the CSLF member nations, as well as business and NGO experts in CCS that contributed to Policy, Technology, and Stakeholder working group meetings. The US Secretary of Energy co-chaired the event with the Minister of Petroleum and Natural Resources from Saudi Arabia. Major NGOs and companies that attended included:

Why was this CSLF Ministerial meeting important?

The CSLF Ministerial meetings help set the direction for research and policy priorities related to CCS around the globe. Energy ministers—as well as the major energy companies, government research units, and NGOs that participated in this meeting—have significant power to shape national and international action to develop CCS technologies. With mounting evidence that CCS will provide a critical tool to not just stop emissions, but to also clean up carbon that has accumulated in the atmosphere, it is increasingly urgent that the CCS community get the support it needs to develop swiftly and effectively.

How did the conversation at the meetings relate to carbon removal?

The CSLF meeting provided interesting insight into the zeitgeist among influential energy ministers, companies, and NGOs about the role that CCS—and fossil fuel use more generally—will play in a world increasingly committed to curtailing climate change.

To start, nearly all of the CSLF meeting participants were bullish on the outlook for fossil fuel consumption, expressing the view that fossil use would increase over the next several decades due to a combination of demand factors (e.g. population and economic growth) and supply factors (e.g. lack of cost-competitive renewable energy). While many outside the CSLF group do not see prolonged fossil energy use as an inevitability, that opposing viewpoint was not voiced at this CSLF meeting.

In addition, the meeting participants voiced a very narrow conception of “carbon sequestration” that was almost entirely confined to technologies that capture CO2 emissions from fossil fuel use coupled with underground geologic CO2 storage—and did not include other carbon removal approaches. This narrow interpretation of the term “carbon sequestration” is striking, as a much broader set of technologies and processes hold potential to capture and store carbon from the atmosphere, including:

  • In the energy sector: CO2 capture from non-fossil fuel sources, including bioenergy and ambient air; and storage via utilization in building materials
  • And outside the energy sector: Biological CO2 capture via photosynthesis and storage in ecosystems (e.g. forests, grasslands, wetlands, oceans) and/or agricultural lands (e.g. soils, biomass); and chemical CO2 capture via enhanced weathering of rocks that natural react (albeit quite slowly) with CO2 in the air.

The bottom line is that, in this influential community, the link between CCS via fossil energy and geological storage and CCS via other carbon removal approaches is largely non-existent.

How does the "CCS = fossil energy" paradigm impede the development of CCS systems?

The participants in the CSLF meetings repeatedly stressed that the problems facing CCS systems are not technological in nature, as the major components of CCS systems have been commercialized over decades of related fossil fuel refining and enhanced oil recovery activities. Instead, the CCS field faces a political problem: there are scant markets and government programs to support CCS projects.

 There was plenty of space at the CLSF Stakeholder table for more voices thinking about carbon sequestration beyond systems related to fossil energy with geologic capture.

There was plenty of space at the CLSF Stakeholder table for more voices thinking about carbon sequestration beyond systems related to fossil energy with geologic capture.

While there was considerable discussion of potential policy, regulatory, and communication tactics that could help build support for the CCS field,  there was no discussion of fundamentally re-framing the conception of CCS to one of “zero- and negative-emission energy (and non-energy) sector technologies.” Such a re-framing could expand CSLF stakeholders and advocates, bringing much needed support for CCS of all kinds. And while I'm proud to report that the CSLF stakeholders unanimously adopted the Center's recommendation to explore opportunities for expanding the definition of "CCS" to include non-fossil fuel sources, we still have a long way to go to make a broader, coordinated "carbon sequestration" discussion a reality.

Science Special — Intro to BECCS

Welcome to this week's edition of Science Friday! Because we are focusing on BECCS this month, our first Science Friday post will serve as an introduction to the technology. 

Our BECCS must reads:

This piece, published in Nature Climate Change, explores the need for BECCS technology in accordance with IPCC projections and assesses the challenges that accompany large scale negative emissions technology deployment. 

Also published in Nature Climate Change, a UC Berkeley team shows how BECCS technology could help enable the transition to carbon negative power across western North America: "We show that BECCS, combined with aggressive renewable deployment and fossil-fuel emission reductions, can enable a carbon-negative power system in western North America by 2050 with up to 145% emissions reduction from 1990 levels."

Finally, this report from the Tyndall Centre for Climate Change Research explains the fundamentals of BECCS technology along with some important considerations to the applications of BECCS that will result in truly negative emissions. 

See you next week! 

Theme of the Month — November: BECCS

This month at Center for Carbon Removal, we will be featuring information on bioenergy with carbon capture and storage (also called BECCS or Bio-CCS). 

BECCS involves traditional bioenergy systems (biomass power or biofuels) coupled with carbon capture and storage (CCS) and has the potential to be a net-negative GHG emission technology. Since biomass feedstocks absorb carbon from the air, the joint use of CCS and sustainable bioenergy production prevents the carbon in the biomass feedstocks from escaping back into the atmosphere during energy production.

 Photo Source: Dan Sanchez et. al

Photo Source: Dan Sanchez et. al

The IPCC's fifth assessment report cites large deployments of BECCS by midcentury in order to keep warming below 2°C — "Mitigation scenarios reaching about 450 ppm CO2eq in 2100 typically involve temporary overshoot of atmospheric concentrations, as do many scenarios reaching about 500 ppm to 550 ppm CO2eq in 2100. Depending on the level of the overshoot, overshoot scenarios typically rely on the availability and widespread deployment of BECCS and afforestation in the second half of the century." (IPCC AR5 SPM). 

Because of its importance in climate modeling and its potential to produce negative emissions on a large scale, this month we will be featuring exciting research and information on BECCS. So share your thoughts about BECCS with us and stay tuned for updates! 

The Good, The Bad, and the Ugly of CO2 Utilization

The concept of CO2 utilization goes something like this: instead of releasing CO2 into the atmosphere through industrial processes, we could instead capture CO2 from smokestacks (and/or the ambient atmosphere) and use this CO2 to manufacture carbon-based products -- such as fuels, food, and construction materials. So what role might CO2 utilization play in fighting climate change? The outlook seems mixed, as explained below.

The Good:

Cost-effective CO2 utilization has a number of interesting implications. First, if CO2 capture costs could come down significantly, existing markets for carbon-based products could drive reductions in carbon emission without the need for pesky-to-implement large-scale GHG regulations. Even with today's CO2 capture and utilization technology, a number of companies are successfully turning would-be CO2 emissions into valuable end products.

Above: The Skyonic "Sky Mine" CO2 utilization facility in San Antonio, TX.

Companies like Skyonic, CarbonCure, Solidia, and Newlight Technologies all show the great potential for this field to drive GHG emission reductions without the need to monetize carbon savings through regulatory programs.

Above: Newlight Technologies has created plastic building blocks from waste GHG emissions from landfills.

The Bad:

The main problem with CO2 utilization today is economics. For one, CO2 from naturally occurring underground reservoirs costs about $10-$20/t, where as capturing would-be CO2 emissions from power plants costs 5x-10x that amount. Capturing CO2 from industrial facilities that produce goods like ethanol or ammonia is more cost competitive, but such industrial facilities can only supply a limited amount of CO2 compared to the 10B+t/year of CO2 that the power sector produces. Companies like Inventys are making great innovations to drive down these costs of capture, but technology still has a fairly long way to develop before it is competitive with naturally occurring CO2.

Another factor holding CO2 utilization back is that, even if CO2 was incredibly inexpensive to capture, it still might not be cost-effective to build products out of CO2. For example, right now, fuels remain considerably less expensive to extract from the ground than to synthesize from CO2. As a result, we will have to drive down not only the cost of CO2 capture (and transport), but also that of manufacturing processes that utilize CO2 in order to make CO2 utilization cost effective.

Without cost reductions in CO2 capture technologies, CO2 utilization is only likely to make a small dent in annually GHG emissions. But while these economic challenges are significant, large-scale R&D programs for innovative CO2 capture technologies could change these economic fundamentals in a major way. The field of CO2 utilization seems similar in many way to the field of solar energy back in the 80s: in the 80s, we had solar technologies that worked, but they made poor businesses in most cases. 30 years of aggressive R&D later, solar is now challenging fossil fuels on an unsubsidized basis in many regions -- CCS could follow a similar trajectory with the right investments in R&D and regulatory support.

The Ugly:

Where it just doesn't seem like the numbers will ever truly be in the favor of CO2 utilization is when it comes to carbon dioxide removal (CDR). With CDR growing increasingly necessary, it would be great if CO2 utilization in carbon-sequestering end products (e.g. products that we make with CO2 and then don't turn immediately back into CO2 emissions) could provide significant negative emissions potential.

CO2 utilization venn
CO2 utilization venn

The potential for CDR from such carbon-sequestering end products, however, looks fairly limited today. The markets for three of the major carbon-based products -- cement, plastics, and timber (when sustainably harvested and used for other purposed besides energy production) -- are fairly modest in overall size in comparison to the prodigious ~35B tonnes of CO2 we emit into the atmosphere annually as "waste."

Carbon Mass
Carbon Mass

The above graphic show how much CO2-equivalent is consumed each year with these various end products. The graphic below translates this into the potential for these as a CO2 sink today and in 2100 (assuming 2% annual growth):

Amount of CO2 potential
Amount of CO2 potential

Links to sources: cement, plastics, timber.

The bottom line is that by the end of the century, we will need a lot more than just carbon-sequestering end products to prevent climate change -- we'll also need large scale decarbonization of the economy. Such decarbonization might rely on CO2 utilization for fuel synthesis, but it also means that we will need to pursue other ways to sequester CO2 emissions, such as by storing carbon in soils through farming techniques or fertilizers, or injecting it underground to monetize potential carbon programs.

So while it looks like CO2 utilization will make incremental gains in the fight against climate change, it doesn't look like we will be able to innovate our way entirely out of our GHG emissions problem, and that some form of regulation will likely be needed to contain global warming.

Direct Air Capture Explained in 10 Questions

Direct Air Capture ("DAC") systems are an emerging class of technologies capable of separating carbon dioxide (CO2) directly from ambient air at large scale. Want to learn more about how DAC systems work and how they can help fight climate change and create a circular economy? We've got 10 Q's and A's below to get you started: 

1.      How do DAC systems work? DAC systems can be thought of as artificial trees. Where trees extract CO2 from the air using photosynthesis, DAC systems extract CO2 from the air using chemicals that bind to CO2 but not to other atmospheric chemicals (such as nitrogen and oxygen). As air passes over the chemicals used in DAC systems, CO2 "sticks" to these chemicals. When energy is added to the system, the purified CO2 "unsticks" from the chemicals, and the chemicals can then be redeployed to capture more CO2 from the air. Check out the video below explaining how Climeworks's DAC system works:

2.      What type of carbon management technology is DAC? DAC systems can be classified as carbon "recycling" or carbon "removal" technologies, depending on what happens with the purified CO2 that the DAC system produces.

  • Recycling: CO2 produced by DAC can be recycled into fuels or other products that release CO2 back into the atmosphere quickly after their use (such as greenhouses, carbonated beverages, etc.). As a carbon recycling tool, DAC systems can provide an important component of a circular economy, where the sky is mined for the raw inputs used in subsequent manufacturing processes.
  • Removal: CO2 produced by DAC that is sequestered in geologic formations underground or in materials that do not allow CO2 to escape into the atmosphere (such as cements or plastics) can generate negative carbon emissions.
 Above: a visualization of what a commercial-scale DAC plant might look like, via  Carbon Engineering .

Above: a visualization of what a commercial-scale DAC plant might look like, via Carbon Engineering.

3.      Are DAC systems classified as energy- or manufacturing-sector technologies? Unfortunately, DAC systems defy easy industry classification. DAC systems can be used to generate the inputs for manufacturing processes. But DAC systems also can operate in similar fashion to energy-sector carbon capture and storage (CCS) technologies. As a result, DAC systems can be considered an energy-sector technology, a manufacturing-sector technology--or both--depending on how it is used.

4.      What are the pros and cons of DAC as a carbon management technology?

  • Pros: Because DAC systems do not need to be sited directly at power plants, they can be sited close to sequestration/manufacturing sites, eliminating the sometimes costly CO2 transportation step associated. In addition, DAC systems take up a relatively small land footprint. A study by the American Physical Society showed that a square kilometer of DAC machines could generate around 1 million tons of CO2/year (meaning that 3 sq-km of DAC projects could offset the same amount of coal power that the Topaz Solar Field does using over 25 sq-km of land)
 The APS report shows that DAC systems can take up relatively little land compared to other renewable energy technologies such as solar or wind.

The APS report shows that DAC systems can take up relatively little land compared to other renewable energy technologies such as solar or wind.

In addition, DAC systems require no biomass inputs, so there is little competition for agricultural land (as there is with other leading carbon removal approaches).

  • Cons: High costs compared to other greenhouse gas abatement approaches.

5.      What organizations are building DAC systems today? The idea of separating CO2 from air is not new, and has been done on submarines and in space applications for decades (it would be impossible to breathe in these closed environments without CO2 capture from air). That said, large-scale DAC systems used for carbon management purposes are only beginning to emerge today, and there are no commercial-scale deployments of DAC systems as of this writing. Today, there are four leading commercial DAC system development efforts, along with one academic center pursuing DAC research:

a.      Carbon Engineering: Based in BC, Canada, Carbon Engineering is pursuing a liquid potassium hydroxide based system. They have a pilot plant in Squamish, BC set for an October, 2015 launch date.

b.      Climeworks: Based in Zurich, Switzerland, Climeworks is employing a novel sorbent coupled with a temperature swing to release the captured CO2. Climeworks has inked a commercial partnerships for CO2 recycling with Sunfire and Audi, and are building a 1,000 ton-per-year plant in Germany to supply a greenhouse with CO2 for its operations.

c.      Global Thermostat: Based in CA, USA, Global Thermostat is pursuing a DAC technology based on proprietary amine sorbents with a temperature swing for regeneration. Global Thermostat has a pilot plant up and running at the SRI headquarters in Menlo Park, CA.

d.      Infinitree: Based in NY, USA, Infinitree is using a humidity swing process for concentrating CO2. They are targeting the greenhouse market for initial customers. This technology is based on the DAC system developed by now-bankrupt Kilimanjaro Energy (formerly Global Research Technologies).

e.      Center for Negative Carbon Emissions at ASU: based in AZ, USA, this academic group headed by professor Klaus Lackner is developing a DAC technology based on a humidity swing process.

 Global Thermostat's pilot plant in Menlo Park.

Global Thermostat's pilot plant in Menlo Park.

DAC for carbon management purposes is a relatively new pursuit because separating CO2 from air is challenging to do in an economically viable way. The main reason for this is that it takes a significant amount of energy and air to separate and concentrate CO2: CO2 exists in the atmosphere in very dilute concentration compared to other chemical elements (CO2 comprises 0.04% of the atmosphere compared to about 78% for nitrogen, and 21% for oxygen). Finding chemical agents that are sticky enough to bind with the few CO2 molecules that exist in the air—but are also not too sticky so that they will easily release the CO2 in the chemical regeneration step—has proven challenging.

6.      How is DAC related to other carbon capture and storage (CCS) systems? In many ways, DAC systems are quite similar to other CCS systems, especially in regards to the chemicals used to capture CO2. Capturing CO2 from ambient air, however, is thermodynamically more challenging than capture from energy systems, as coal power plants generate exhaust gas with around 15% concentration of CO2, natural gas power plants around 5%, and ambient air has around 0.04%. This relatively dilute stream of CO2 in the air requires DAC systems to deploy novel engineering designs, as traditional CCS systems would require a prohibitive amount of energy to capture CO2 directly from the air.

7.      How much energy is required for DAC? It depends on how efficient the air capture process is, and what ending concentration of CO2 is required. To get 100% pure CO2 stream at the maximum possible efficiency, the American Physical Society report cites that it takes approximately 497 kJ of energy to generate 1 kg of compressed CO2. In other words, for every million tons of compressed CO2 generated from a maximally efficient DAC system, a power plant running at 100% capacity factor of 10 MW is required. To get to the billion ton scale of CO2 capture viewed by many experts as climatically significant, DAC systems would thus require about 10 GW of power, equal to about 3 times the capacity of the largest nuclear plant in the US.

 A visualization of what an "artificial forest" of DAC machines might look like when coupled with renewable energy, via the ASU Center for Negative Carbon Emissions.

A visualization of what an "artificial forest" of DAC machines might look like when coupled with renewable energy, via the ASU Center for Negative Carbon Emissions.

8.      How much does DAC cost? At commercial scale, no one really knows. Estimates range from around $60/ton of captured CO2 at the low end (for only CO2 capture) to $1000/ton of CO2 at the high end (for both capture and regeneration) according to a recent National Research Council study (on page 72). The eventual cost of DAC systems will likely depend on how efficient manufacturing for DAC systems becomes. Because there are no commercial scale deployments of DAC systems, however, it is very difficult to estimate how quickly costs will come down. It is likely that the first commercial-scale DAC projects will cost several hundreds of dollars per ton of concentrated CO2, but as manufacturing improves over time, these costs are likely to come down significantly, especially if DAC is manufactured modularly like many startups are attempting to do. It is also likely that operating costs will come down overtime as novel chemical structures are developed that cost less and/or require less material than existing capture chemicals.

 DAC system costs are likely to come down with larger scale deployments, much like other clean energy technologies such as wind energy have, especially if DAC systems are manufactured modularly. 

DAC system costs are likely to come down with larger scale deployments, much like other clean energy technologies such as wind energy have, especially if DAC systems are manufactured modularly. 

9.      What are the revenue opportunities DAC? In the future, carbon markets or regulations can provide large sources of revenue for DAC system operators. Without carbon prices, DAC systems are likely to find the largest revenue opportunities by providing CO2 for manufacturing fuels, or for use in enhanced oil recovery (as many oil fields are located far from CO2 pipelines, making them ideal candidates for flexibly-sited DAC systems). Smaller, high value markets (such as greenhouses, carbonated beverages, etc.) can provide early revenue opportunities. 

 Audi's "e-diesel" uses Climeworks's DAC system. Transportation fuels can provide an early revenue opportunity for DAC companies.

Audi's "e-diesel" uses Climeworks's DAC system. Transportation fuels can provide an early revenue opportunity for DAC companies.

10.   Are there any policies related to DAC today? Very few. The US Federal government has provided a $3M solicitation from the DOE to support the development of DAC systems, and there is language providing $250k for research and development in the Senate Energy and Water Appropriations Bill report language. In addition, the provincial government of Alberta in Canada has provided grant support for DAC companies through the CCEMC. DAC will benefit from ongoing policy advances around the utilization and geologic storage of CO2, and potentially from the development of carbon markets that are considering traditional CCS as a compliance option. Nevertheless, DAC systems would likely require specific policy treatment in any carbon regulatory system, and so far there has been very little discussion about how to incorporate DAC into any of these existing/potential policy structures.

Bonus question: Want to learn more? Check out our list of links related to DAC, and share your own favorite resources in the comments section!


Thanks to Avi Ringer, Matt Lucas, and Daniel Sanchez for helping to prepare this post.

Theme of the Month - September: Direct Air Capture

This month at the Center for Carbon Removal, we will be featuring the work of a number of innovators building direct air capture machines. Direct air capture technologies are capable of separating carbon dioxide directly from ambient air. The concentrated carbon dioxide that these systems produce can then be used to build carbon-based products (such as cements, plastics, and fuels), or buried deep underground to receive carbon credits.

Over the next month, we will be highlighting some of the different approaches direct air capture innovators are pursuing, and highlighting innovative direct air capture companies such as:

We will also be taking a closer look at some of the academic centers pursuing carbon removal solutions, such as the Center for Negative Carbon Emissions at Arizona State University, and we'll be highlighting technical work related to direct air capture all month during our weekly Science Friday blog posts.

So share your thoughts about direct air capture with us, and we look forward to highlighting interesting stories in the field all month long!

Carbon Removal Dialogue: Fossil CCS as a bridge technology?

Welcome to the "Carbon Removal Dialogue," a new feature on the Center For Carbon Removal blog where we ask experts to share their thoughts on important questions related to carbon removal. We'll consolidate the responses into a single post, and we hope that the dialogue continues in the comment section, below.

Thanks to all of the experts that have responded, and without further ado, our first Carbon Removal Dialogue...


Can fossil energy with carbon capture and storage (CCS) be a bridge to net-negative CCS systems, including bioenergy with CCS and direct air capture and sequestration? If so, how; and if not, why not?

Can fossil energy with carbon capture and storage (CCS) be a bridge to net-negative CCS systems?


Brent R. Constantz, Ph.D.

Chief Executive Officer

Blue Planet Ltd.

CCS depends on purifying CO2 from fossil flue gas from coal and natural gas fired power plants and cement plants. The step of extracting and purifying the CO2 from a dilute state (12 - 15% for coal, 3 - 5% for natural gas, and 20 - 30% for cement) is the most significant problem with CCS because of the very large energy demand to purify it to near 100% for compression and liquification, transport, storage and monitoring. No process that requires a high energy demand purification step using conventional methods will ever, even at the theoretical best, lead to any sustainable carbon removal solution due to the energy required for the purification step. I don’t see a need for purification in net-negative systems, and if they would include the purification step, they would have to have a new novel approach (such as Blue Planet) that is different from the purification step processes currently being developed and funded. In general, I don’t think continued efforts on the conventional carbon dioxide purification processes being pursued for compression and liquification will help bridge to net-negative CCS system (or CCUS).


Roger D. Aines

Fuel Cycle Innovations Program Leader

Lawrence Livermore National Laboratory

The 10 million tons of CO2 placed in underground storage by the US CCS demonstration programs demonstrates that we can put CO2 out of reach of the atmosphere, a critical requirement for any carbon dioxide removal method. These kind of technology innovations and demonstrations will pave the way for bio-CCS and atmospheric capture.

  A diagram illustrating CCS technology. Photo credit: 21st Century Technology

A diagram illustrating CCS technology. Photo credit: 21st Century Technology

George Peridas

Scientist - Climate & Clean Air Program

Deputy Director - Science Center Program

Natural Resources Defense Council

Combating climate change requires us to reduce carbon pollution significantly, and to do so fast. In an effort to quantify how much more carbon the atmosphere can tolerate while giving us a decent chance of avoiding dangerous climate change, researchers talk about “carbon budgets.” Between now and 2050, the budget is around the 500 billion metric tons of CO2 mark, and a little under double that by the end of the century. The problem is how we use fossil fuels today. Collectively, the world’s proven fossil fuel reserves as we know them today would generate close to 3,000 billion metric tons of CO2 – many times over the safe limit. Clearly, we cannot use these fossil fuels reserves without frying the planet. Moreover, almost 35% of the world’s installed capacity of coal-fired power plants – the worst cumulative carbon perpetrators – is ten years old or less. These plants are commonly worth upward of a billion dollars, and have a projected lifetime of several decades. Alone, they will take up the lion’s share of the allowed carbon budget. We need a means of substantially reducing their carbon emissions.

That’s where Carbon Capture & Sequestration (CCS) comes in. This is a technology that is ready to be used today at scale, but needs a cheaper price tag to become more widespread – something that targeted deployment programs will take care of if governments pursue them seriously. Will it actually be used, and will it be enough? A prudent approach does not assume that the answer is “yes”. Finding ways to remove carbon directly from the atmosphere, whether they are based on biomass or direct engineering, could enhance our capabilities and options if we delay emission cuts, or blow our carbon budget. Open questions remain today, however, on the economics, scalability and life cycle carbon footprint for many processes that remove carbon directly from the atmosphere. Achieving progress in this area would be very beneficial. It is not clear whether conventional CCS is a pathway to commercializing atmospheric removal technologies. To the extent that the latter rely on geologic sequestration to achieve an overall negative carbon footprint, then CCS can fast track the development of injection sites and experience in operating these. Beyond that, at this point the approaches strike me as sufficiently distinct that the fate of one is not tied to the fate of the other. However, both are worth pursuing independently: CCS as a climate mitigation measure that could begin reducing emissions meaningfully today, and atmospheric removal approaches as processes that need to be further developed, tested and refined so that they establish themselves as affordable, scalable and effective approaches to achieving net-negative emissions.


Daniel L. Sanchez

Ph.D. Candidate, Energy and Resources Group

University of California-Berkeley

Absolutely. Fossil CCS is not just a bridge to BECCS and other carbon-negative energy systems, but an essential part of their path to commercialization. Not only do advanced fossil and advanced biomass conversion systems share common characteristics, but co-conversion of coal, natural gas, and biomass enables producers to meet a variety of cost, performance, and carbon-intensity goals. This optionality is key to any path to market for BECCS.

There are some notable exceptions, however: biomass resources are more distributed than fossil resources, and transportation can be costly and complex. Biomass combustion and gasification is also more complicated than similar processes for coal and natural gas.

More broadly, carbon dioxide removal shares many characteristics with other carbon management techniques: this applies to both chemical and biological strategies to remove CO2 from the atmosphere. This means that any future "carbon removal" industry and "carbon management" industry can work together to both reduce emissions of CO2 to the atmosphere, AND concentrations of CO2 in the atmosphere.

Dan Miller

Managing Director

Roda Group

I agree we are going to need net negative emissions because CO2 levels are already too high (and they will go higher). When it comes to fossil CCS, the need is obvious.  Since CO2 lasts in the atmosphere for a very long time (100’s to 1000’s of years) it is the total cumulative amount of emissions that matter.  A ton of CO2 that is captured and sequestered from a coal or natural gas power plant is one ton less that needs to be captured from the air or some other “net negative” scheme. And since capture from power plants and other “point sources” is far less expensive than air capture, it makes sense to focus CCS on power plants (fossil or bio) right now.  Yes, we should shut down coal plants and phase out natural gas power plants as soon as possible, but I don’t see that happening until way beyond the “too late” stage.

We need to commercialize CCS technology right away and that means fossil plants for now.  Air capture is still in the R&D stage and needs more work before it becomes practical and affordable. Also note that CCS technology is not the issue.  Incentives (and regulations) are.  Right now, power plant operators can pollute for free.  Until we change that, no technology that costs more than $0/ton will have widespread deployment.  The best way to implement the proper incentives is with a Fee and Dividend policy.  See my TEDx talk on that

As for bio-power plus CCS, it’s good scheme but I understand that the amount of bio material available for power production is limited compared to our power needs and the amount of CO2 we need to remove from the atmosphere.  We therefore need to also focus on wind and solar (and nuclear) for power generation and “mechanical” CCS and air capture.

As for paving the way, fossil CCS will give us experience with carbon sequestration and utilization (turning CO2 into something useful).  Also, point source CCS can be the “second stage” of an air capture system (and can be directly used in a bio-energy power plant).


  An explanation of how the planned BECCS plant in the UK will produce negative emissions. Photo credit: Drax Power

An explanation of how the planned BECCS plant in the UK will produce negative emissions. Photo credit: Drax Power

Victor Der

Executive Advisor

Acting General Manager- Americas

Global CCS Institute

CCS for not only fossil but also for other industries that have no other choice but CCS in removing carbon emissions is indeed a GATEWAY technology to net negative CCS systems such as BECCS. Bio energy as a renewable energy form  can provide near neutral emissions, but when combined with CCS, the result is net negative emissions.

One of the key technical challenges for CCS is reducing its cost (primarily in capture) which requires research, development, demonstration and deployment so we can learn by doing.  A key challenges for bio energy is in reducing the energy and costs of gathering bio feedstocks to produce bio energy. These dual challenges are important to the large scale deployment of BECCS.  With CCS projects operating or under construction and many more at various stages, a solid foundation for CCS is being established that will allow it to be broaden to such applications as BECCS. For example, in the UK, there is the White Rose capture project that will burn wood chips and capture the carbon emissions for storage under the North Sea is a BECCS project. I refer you to the article in the New Scientist at

In addition the Climate Institute produced a BECCS report which the Global CCS Institute commissioned a year ago and is worth a read. With respect to direct air capture, which is in a nascent development stage and thus currently a longer range option, reducing the cost of CCS through transformational technologies is even more important to that application. The current focus of research on transformational technologies for reducing  capture costs in CCS is a high priority for the US Department of Energy given its recent announcement of 16 research projects on transformational capture technologies for fossil based systems.


Sasha Mackler

Vice President, Summit Carbon Capture

Summit Power Group, LLC

Fossil CCS offers a platform that will, over time, lead to numerous other forms of CCS across various technologies with ever increasing CO2 benefits. This holds true even with marginal technology overlap between existing forms of CCS that can be applied to power plants today and the sorts of carbon negative systems being envisioned in the future. This is because the regulatory frameworks, policy designs, supporting technologies, and intellectual capacity that are formed around fossil CCS will expand to include and eventually drive deeper reductions through other techniques to capture and store CO2. For example, it will take time to establish rigorous and workable CO2 storage regulatory regimes that include protocols for certifying long-term storage, methodologies for generating environmental credits, and commercial approaches for managing long-term storage liabilities. If these matters can be sorted out around fossil CCS projects now, then they can be leveraged to support more innovative carbon dioxide removal schemes later. The lack of such practical frameworks will serve as a barrier to innovation and commercial progress in the field of carbon removal.




Center For Carbon Removal

Not only do I think fossil energy with CCS can serve as bridge to bioenergy with CCS, but I think that it must serve as a bridge for either technology to gain widespread adoption. Here's why:

Bioenergy with CCS (bio-CCS) needs fossil energy with CCS. The more fossil energy with CCS projects that get built, the lower costs (such as technology, regulatory, project finance, etc.) become for many CCS projects. Because fossil energy with CCS is less expensive than bio-CCS, it is more likely to find economically viable market opportunities in the near-term. Without fossil CCS projects driving down bio-CCS costs, I worry that we will always see bio-CCS as too expensive an option, and we won't pursue the R&D investments needed to bring down costs to acceptable levels.

But fossil energy with CCS also needs bio-CCS. Many renewable energy advocates see fossil CCS as enabling “business as usual” for polluting energy companies, and thus do not throw their support behind programs to support early deployments of fossil CCS projects. “Renewable CCS” in the form of bio-CCS, however, is something that renewable energy advocates are naturally more inclined to support. If fossil energy with CCS projects can credibly commit to serving as a bridge to bio-CCS in the future (through agreements to ratchet up biomass co-firing, or by supporting RPS-like standards for bio-CCS in the future, for example), they are more likely to get the support they need to get early projects built and deployed.

Have an idea for a dialogue question? Email us ( or leave it in the comments below! 

The US EPA Clean Power Plan: What it means for carbon removal solutions.

On August 3rd, the Obama Administration released the Clean Power Plan (CPP) in an effort to regulate greenhouse gas emissions from the electric power sector in the US.  The CPP provides an important and necessary first step for the US to start reducing emissions from power plants. Yet the relatively modest climate ambition and scope of the plan makes it even more critical to expand the President’s larger plan to curtail climate change to include new measures that foster the development of carbon removal solutions today. Here's our take on what the CPP does (and does not) do to foster the development for carbon removal solutions, and what it all means for the carbon removal field.

First, some background:

The Clean Power Plan (CPP) relies on the authority of the Environmental Protection Agency (EPA) to regulate pollution (including the “carbon pollution” causing climate change) under Section 111(d) of the Clean Air Act (here's a great resource explaining the details of the CPP). Specifically, the CPP requires that states individually cut emissions from existing power plants by 2030. As a result, the CPP is limited to controlling emissions from only a small (but significant) subset of overall greenhouse gas emissions.  Because the CPP is limited to existing power plants, many carbon removal approaches in the agriculture, forestry, and mining sectors (for example) are likely out of scope of the CPP regulatory authority. 

  Sources of greenhouse gas emissions in the US, from the EPA . The electric sector emissions covered under the CPP represent a minority, but significant portion of total emissions in the US.

Sources of greenhouse gas emissions in the US, from the EPA. The electric sector emissions covered under the CPP represent a minority, but significant portion of total emissions in the US.

Modest climate ambition in the CPP = greater need for carbon removal solutions.

When implemented, the Clean Power Plan (CPP) will reduce emissions from power plants by 32% by 2030 from 2005 levels, accounting for about 10% of reductions of from total US emissions in 2005. However, the U.S. has pledged to reduce emissions by 26-28% from 2005 levels by 2025 in its internationally determined contribution (INDC) to the UN process, meaning that the US must make more than an additional 16% reduction from fuel efficiency standards, energy efficiency programs, non-CO2 greenhouse gas (e.g. methane, hydrofluorocarbons) reductions, and other components of Obama’s climate action plan in order to meet its INDC. So while the CPP may be political ambitious, it represents is only a small piece of what needs to be a more aggressive climate mitigation portfolio to align us with 2 degrees C warming scenarios that avoid dangerous climate change.

Because the emissions reductions proposed in the CPP are gradual and relatively modest, it is imperative that the US simultaneously develop and implement complementary policies that encourage the development of carbon removal solutions. Between now and 2030, we will continue to emit significant (albeit reduced) volumes of carbon dioxide emissions, and will likely need carbon removal solutions to clean up the carbon dioxide that accumulates in the atmosphere from this activity. 

So does the CPP do anything to incentivize the development of carbon removal solutions?

Not explicitly. The Clean Power Plan (CPP) likely would enable states to comply with their plan with carbon removal technologies that also produce power from stationary sources (e.g. bioenergy with carbon capture and storage (CCS)). But as mentioned earlier, it is unlikely that the CPP would enable compliance through non-power-sector carbon removal approaches like reforestation, direct air capture, and enhanced weathering, which are "outside the fence" of existing power plants and likely off limits for CPP regulation.

What's more, there are no special incentives for developing power-sector carbon removal solutions in the CPP. As a result, even though the CPP allows some carbon removal technologies such as bioenergy with CCS to comply with the CPP, it is unlikely that states will choose to deploy these technologies, as it likely will cost less for states to comply through the more established, less-expensive mitigation technologies listed as options for CPP compliance. In other words, it is unlikely that the CPP will provide the support that regulations such as PURPA or the PTC/ITC did for other renewable technologies (like solar and wind) back in the 80s and 90s.

Nevertheless, the CPP does help with the development of carbon removal solutions in two indirect ways:

1. Clearing up regulations around fossil energy with carbon capture and storage (CCS).

The Clean Power Plan (CPP) regulations do recognize the ability for fossil energy with CCS technology to help states meet their targets, but do not mandate it, citing high cost as a barrier to implementation across the entire industry. The EPA language states:

“Use of full or partial CCS technology should not be part of the BSER [best system of emissions reduction] for existing EGUs [electricity generating units] because it would be more expensive than the measures determined to be part of the BSER, particularly if applied broadly to the overall source category.”

Even by keeping the door open for fossil CCS projects (if not mandating the technology outright), the EPA has provided an opportunity for utilities and project developers to build fossil energy with CCS projects, and hopefully pave the way for carbon removal CCS techniques such as bioenergy with CCS and direct air capture and storage in the future. Early fossil energy with CCS projects can prove critical for examining uncertainties pertinent both to fossil CCS and carbon removal CCS (such as geologic storage concerns), as well as for helping to bring down costs related to the development of both fossil and renewable CCS projects.

2. Building a bridge to smart, sustainable bioenergy with CCS projects

Biomass energy under the Clean Power Plan is considered an emissions control technology, but the EPA has expressed concern with the sustainability of many biomass feedstocks. The EPA said it is

“not scientifically valid to assume that all biogenic feedstocks are ‘carbon neutral, but that the net biogenic CO2 atmospheric contribution of different biomass feedstocks can vary and depends on various factors, including feedstock type, production practices, and, in some cases, the alternative fate of the feedstock.’”

The EPA will consider this biomass accounting when approving each individual state’s CPP compliance plan, requiring each state to describe the types of biomass, how those proposed feedstocks should be considered, and measures for tracking and auditing performance. Thus, the EPA has the authority to deny any insufficient interpretation of sustainable feedstocks, but their execution in approving or denying biomass plans that do not result in emissions reductions is key.

This critical eye towards biomass lifecycle carbon account is important for ensuring carbon removal techniques such as bioenergy with CCS actually generate net negative carbon emissions in the future. Getting this accounting correct today for bioenergy projects without CCS will prove critical for the future of carbon removal.


It has become increasingly clear that the Administration's climate action plan, of which the Clean Power Plan is a critical part, is characterized by modest, gradual emissions reductions, that will likely be insufficient to curtail dangerous climate change without significant ratcheting in the near future. As a result, it is increasingly imperative that we also develop negative emissions technologies as part of our broader climate mitigation strategy. And while the CPP doesn't entirely exclude carbon removal approaches, it is unlikely to provide the regulatory tool needed to accelerate the development of these vital solutions.


Clean technology research and development is critical for curtailing climate change. But is it enough?

A number of leaders in the energy/climate field, from Bill Gates to a group of British climate experts, have recently called for governments across the world to significantly increase spending on research and development (R&D) for clean energy technologies. Implicit in many of these calls for R&D, however, is the misleading idea that the climate change problem can be solved mainly by investments in clean technology R&D. Take the Global Apollo Project report, for example:

"One thing would be enough to [make energy clean]: if clean energy became less costly to produce than energy based on coal, gas or oil. Once this happened, the coal, gas and oil would simply stay in the ground."


“One thing would be enough to make it happen: if clean energy became less costly to produce than energy based on coal, gas or oil. Once this happened, the coal, gas and oil would simply stay in the ground.”
— A Global Apollo Program to Combat Climate Change

While the statement above is true -- and while more publicly funded R&D into all greenhouse gas abatement strategies (including carbon removal) is almost certainly a positive thing -- focusing exclusively on this "one thing" to fight climate change is likely sub-optimal for a number of reasons:

  1. First, there is another way to keep fossil fuels in the ground: regulation. Governments can either impose taxes on carbon-intensive fuels, or simply restrict their use outright. In fact, such regulation would likely spur significant private-sector R&D into clean energy technologies, in the end accomplishing similar (or even deeper) cost reductions for clean energy technologies as compared to cost reductions from public-sector R&D efforts. Most governments have done a poor job of regulating carbon emissions to date -- and have found that climate regulation garners less political support than clean energy R&D -- but smart climate regulation is too valuable a tool to shelve for a focus only on R&D.
  2. Second, a focus on clean energy R&D buries the importance of a key variable in the fight against climate change: time. Cost reductions for clean energy technologies can take significant amounts of time -- event with massive R&D pushes. And we don't have time to wait for R&D to reduce the costs of clean energy, raising the importance of complementary strategies to reduce emissions.
  3. Third, the fact that not all fossil fuels cost the same amount to produce increases the challenges for clean energy systems. Take the oil supply curve, below, for example:

For clean energy to out-compete all supplies of oil on price alone, they can't just get below the current price of oil -- they will have to get below the lowest-cost oil supplies, which are very cheap. This level of cost reduction is hopefully possible to accomplish with massive investments in R&D, but there is significant risk that such cost reductions will not happen at the pace needed to curtail climate change. One strategy to reduce this challenge is to make the cost of these inexpensive fossil resources through smart regulation. Alternatively, policies that encourage the development and deployment of carbon removal systems could enable us to meet climate goals even if R&D efforts to reduce costs of clean energy systems didn't result in prices low enough to displace all carbon emissions.

The bottom line:

While something like a Global Apollo program for clean energy (and for other climate change abatement strategies too) is almost certainly a good idea, society risks moving too slowly to curtail climate change by focusing primarily on R&D. Instead, pursuing parallel policy pathways that increase the cost of extracting and using carbon-intensive fuels alongside clean technology R&D efforts can help ensure that we decarbonize as swiftly as needed to curtail climate change -- and that we do so in as economically-viable and sustainable a manner as possible. 

Three Lessons Carbon Removal Can Learn from the Low Carbon Energy Investor Forum

The state of carbon removal technologies in investment today is akin to the beginnings of other now well-known mitigation technologies like solar, wind, and energy efficiency. Scaled demonstration projects, industry and policy support, and an open dialogue on the potential for carbon removal technologies is imperative to preventing climate change

Throwing the Carbon Capture Baby out with the Coal Bath Water

The environmental advocacy group Greenpeace recently released a report lambasting carbon capture and storage (or "CCS") as "a false climate solution" that "[i]n no uncertain terms...hurts the climate." The Greenpeace analysis, however, made a number of assumptions that fit the conventional wisdom surrounding CCS, but when analyzed with greater scrutiny turn out to be deceptively misleading. Misleading Assumption 1: CCS requires that we prolong coal use. Can we have CCS without coal? From a technical point of view, of course. The California Energy Commission just held a workshop on natural gas power generation and CCS, a handful of companies and researchers are working on direct air capture systems that can pull carbon from ambient air, and researchers across the globe have begun thinking about carbon-negative bio-energy and CCS projects. It may be politically infeasible to start developing CCS on these non-coal resources, but a compromise could be to ensure that we phase out coal CCS in favor of non-coal CCS. Regardless, it's too early to say whether these non-coal (and even renewable!) CCS systems can play a large role in fighting climate change, because we simply have not done enough research and development to have good data on these systems. Throwing out renewable CCS today as the unrealistic dreams of "techno-optimists" is analogous to stopping the development of solar energy back in the 1970s because it was over 100 times more expensive than it is today.

(Update: presentations from CEC workshop on natural gas + CCS available here.)

Solar PV chart
Solar PV chart

Above: Data from Bloomberg New Energy Finance

Misleading Assumption 2: It is inevitable that CCS will lead to increased EOR. Can we do CCS without EOR? Yes. There are a number of demonstration plants across the world injecting CO2 underground that involve no EOR. If we don't want EOR, we simply need to regulate CCS so that it can be cost-effective without additional fuel production. Such a pathway will increase the cost of CCS, and there is a much more valid and nuanced debate than what the Greenpeace analysis provides on whether we should pursue EOR in combination with CCS that focuses on using EOR as a pathway to net-negative emissions. But if we wanted to assume that EOR was entirely undesirable, we could still have CCS -- it would just cost more than it would in conjunction with EOR.

Misleading Assumption 3: Underground storage of carbon is required for sequestration. Does carbon have to be stored underground? No. We can turn it into cement, plastics, or any number of other solid products. Will there be issues with storing large volumes of solid carbon above ground? Probably. But we can get around the geologic sequestration problem if we wanted to accomplish this goal.

So can CCS hurt the climate if done wrong? Certainly. But is Greenpeace justified in saying that "in no uncertain terms" CCS "hurts the environment?" Certainly not.

As a result, I remain unconvinced that we should throw out CCS as a climate solution today. Instead, environmental advocates should strive to make clear all of the potential pitfalls of CCS, and ensure that its development balances these environmental and social concerns with the economic considerations of the companies and regulators responsible for deploying these solutions. If you think coal is bad, fight coal. If you think EOR is bad, fight EOR. If you think geologic sequestration is bad, fight geologic sequestration. But we can make a world where coal, EOR, and geologic sequestration do not exist but where large-scale CCS still flourishes if we so choose. While this world might seem far from reality today, it might be the only world where we can prevent catastrophic climate change, as most renewable energy solutions (like wind, solar, geothermal, etc.) are not capable of generating the net-negative emissions we likely need to prevent climate change.

Carbon removal wedges
Carbon removal wedges

Above: adapted from the Climate Institute "Moving Below Zero" report 

So let's stop entangling CCS inappropriately with arguments against related energy systems, because we can decouple CCS from these system is we choose. If we keep conflating CCS with these other arguments, we risk throwing out the CCS baby with the coal bathwater.

"Carbon-removing" gas stations: the future of transportation?

gas stations
gas stations

Over the past several decades, gas stations have remained largely immune to the disruption that has radically altered other industries. But as climate change continues to increase, the imperative for innovation at the pump will start to increase significantly.

Above: A time traveler from the 1970s would recognize today's gas stations. The same could not be said about telephones...

Today, moving people and goods around the planet accounts for nearly 15% of global carbon emissions:

-images-Assessment Reports-AR5 - WG3-Chapter 01-03_figure_1.3 (1)
-images-Assessment Reports-AR5 - WG3-Chapter 01-03_figure_1.3 (1)

Above:IPCC Working Group 3 Chapter 1 Assessment Report 5 Figure 1.3

Scientists, however, are increasinglyconvinced that we will need to not just eliminate those emissions, but also remove and sequester large volumes of excess carbon from our atmosphere and/or oceans to prevent climate change. In effect, the carbon-emitting gas station of today is incompatible with the carbon-removing transportation sector that is required to prevent climate change. As a result, a central challenge for gas stations will be innovation: how can the gas station of the future remove excess carbon from the atmosphere instead of emit underground reserves of carbon into the atmosphere?

Fortunately, a handful of approaches have already started to emerge that offer the prospect of carbon-removing gas stations in the not-too-distant future:

Approach #1: Fill gas pumps with carbon-negative biofuels. Sustainably-grown biomass can be transformed through thermochemical processes into liquid fuels with a low carbon footprint. If some of the emissions associated with the biomass conversion are captured and sequestered underground, the net emissions from these fuels can be negative -- meaning that each gallon of fuel actually sequesters more carbon from the atmosphere than it emits. While biofuels already supply a significant portion of fuel consumed in the UStoday's biofuels are nowhere close to having even a net-zero emissions profile. To achieve net-negative emission profiles, then, biofuel projects will require capture and sequestration of emissions, such as the technology demonstrated at the Midwest Geologic Sequestration Consortium project.

Above: theADM ethanol production facility in Decatur, Illinoiscapturing carbon emissions and sequestering them underground.

Approach #2. Use direct air capture systems to make fuels from excess carbon in the atmosphere.Audi has recently engaged the Swiss startup Climeworks to produce a carbon-neutral gasoline alternative using the Climeworks direct air capture technology. Coupling systems like those Audi is developing with sequestration projects could eventually result in fuels with carbon-negative emission profiles.

Above:Audi makes "e-diesel" using a Climeworks direct air capture system at this plant in Germany.

Of course, the gas station of the future might not actually sell gasoline: we could ditch the internal combustion engine altogether for other types of "engines" that are powered with carbon-negative sources of energy.For example, we could transform our vehicles to run on electricity supplied by a carbon-negative power grid (which could be achieved through utilizing biomass energy with carbon capture and storage, nuclear energy with direct air capture systems, and/or pyrolysis systems that produce electricity and biochar). Another alternative would be to develop carbon-negative sources of hydrogen for fuel-cell-based transportation systems.

But exactly what the carbon-removing gas station of the future looks like is far from certain. For example, the sustainable supply of biomass could be much smaller than is needed to supply carbon-negative biofuel demand. Direct air capture systems likely would add a significant premium to gas prices (even compared to biofuel alternatives), making their widespread adoption politically/economically challenging. And the electrification of heavy-duty transportation (aviation, shipping, etc.) is notoriously difficult to accomplish, making it challenging to generate net-negative emissions across the entire transportation sector if only electrification were pursued.

So in all likelihood, the gas station of the future will look like a combination of all of the above options. But if our society is going to mitigate climate change, one thing is for certain: tomorrow's gas stations will need to be significantly different from today's.

Biomass Sustainability: Critical for Carbon Removal

Today, prominent climate models project that biomass energy with carbon capture and storage ("bio-CCS") projects will play a significant role in the fight against climate change:

Above: The blue line in the chart above, from the paper "BECCS capability of dedicated bioenergy crops under a future land-use scenario targeting net negative carbon emissions" by Etsushi Kato and Yoshiki Yamagata, shows that billions of tonnes of biomass will be needed to generate the net-negative carbon emissions required to prevent climate change. 

Deploying such large quantities of bio-CCS, however, will not be without its challenges, as highlighted by a recent report from the World Resources Institute (WRI). For example, the report finds that "dedicating crops and/or land to generating bioenergy makes it harder to sustainably feed the planet."

WRI Figure 3
WRI Figure 3

Above: Figure from the WRI report "Avoiding Bioenergy Competition for Food Crops and Land"

The report, however, goes on to conclude that "phasing out bioenergy that uses crops or that otherwise makes dedicated use of land is a sound step toward a sustainable food future." A sustainable food future, perhaps. But a sustainable climate future? This recommendation to phase out dedicated bio-energy crops would severely curtail biomass energy fuel supplies, in the process making billion+ ton deployments of bio-CCS very challenging.

What's more, the suggestion from the WRI report of deploying solar PV instead of bioenergy is likely to increase the cost of negative-emission goals considerably. Solar PV could be used with direct air capture ("DAC") systems with CCS to remove carbon from the atmosphere, but today this type of carbon dioxide removal ("CDR") system would likely cost significantly more than biomass-based CDR projects.

The potential for bio-CCS to provide large-scale, cost-effective CDR is an often overlooked aspect of the bioenergy conversation. But the WRI report does specifically provide three such reasons why even pursuing bio-CCS for CDR is not worthwhile. The rationale given for each argument, however, falls flat:

WRI Report Argument Against Bio-CCS #1: "Carbon capture does not transform non-additional biomass that cannot generate carbon savings into additional biomass that can." Bio-CCS can utilize "additional" biomass -- cellulosic ethanol projects that utilize crop wastes, for example, have been slow to develop, but that doesn't mean such projects cannot scale up with the right policy and market support. It will be important to ensure sustainability and "additionality" of biomass supplies for energy, and while this is likely to prove challenging, it is far from impossible. Argument grade: C

WRI Report Argument Against Bio-CCS #2: "There is no benefit to applying carbon capture and storage even to additional biomass until all fossil fuel emissions have been eliminated or captured and stored." There might not be benefits to atmospheric carbon concentrations, but there are almost certainly benefits for learning how to optimize bioenergy systems, build out biomass supply chains, and smooth the transition to a carbon-removing economy. If our economy eventually has to generate net-negative levels of carbon emissions, it will prove politically and economically beneficial to de-risk bio-CCS technology as much as possible today so that once we do stop using coal and natural gas, we are able to generate energy from biomass as economically as possible. Argument grade: D.

WRI Report Argument Against Bio-CCS #3: "even if there were a special benefit from BECCS, this is not a reason to use biomass today without carbon capture and storage." The same logic applies as above: it is important to de-risk biomass generation systems and build biomass supply chains today. Biomass projects without CCS technology could pave the way for most cost-effective bio-CCS project in the future. Argument grade: D.

So where does this leave us? The most important conclusion is that we are likely going to need both increased crop production and increased bioenergy consumption to prevent climate change while feeding a growing population. As a result, it is critical that we expand the conversation on developing systems that achieve both goals. We need to understand the conditions under which bioenergy can be scaled "additionally" and sustainably, so we can focus on building the most sustainable and cost-effective portfolio of CDR systems to prevent climate change while meeting the other basic social and environmental needs of a growing global population.