Archive for the ‘Carbon capture & storage’ Category

Do we focus too much on electricity?

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A recent article posted on the GreenMoney e-jounal site argues that society is moving rapidly into a period of structural (and possibly abrupt) decline in fossil fuel use. The story, like many which argue along similar lines, draws on the current upward trend in renewable electricity deployment, noting that “Renewable energies have become too economically competitive for fossil fuels to contend with . . . “.

While this may be true at the margin when generating electricity, what does it mean for the energy system as a whole? Oil, gas and coal make up 80% of primary energy use (Source: IEA World Balance 2013), although it is often argued that this isn’t a representative picture as a significant percentage of the energy in fossil fuels is wasted as heat loss in power plants, which wouldn’t be the case for a technology such as solar PV. However, moving past primary energy and looking instead at final energy (i.e. the energy which we use to generate energy services such as mobility – so gasoline is a final energy whereas crude oil is primary energy) we see that oil products, natural gas and fuels such as metallurgical coal still make up two thirds of energy use, with electricity and heat comprising just over 20% of the mix. The balance is biofuels (comprising liquid fuels and direct use of biomass) and waste (IEA Sankey Chart for 2013).

Today electricity is generated primarily from coal and natural gas, with nuclear and hydroelectricity making up most of the difference. In 2014 the world generated 23,536 TWhrs of electricity, of which wind was 706 TWhrs (3%) and solar 185 TWhrs (<1%). Wind grew at 10% and solar at nearly 40% compared to the previous year (Source: BP Statistical Review of World Energy). This contrasts with an overall growth in electricity generation of 1.5% per annum. It is certainly possible to imagine a world in which solar and wind grow to dominate electricity production, but then we also need to imagine a world in which electricity grows to become the dominant final energy for renewables to dominate the energy system overall.

This is one of the key subjects that is dealt with in a recent Shell publication that I have worked on during this year; A Better Life With a Healthy Planet – Pathways to Net-Zero Emissions. For me, the most telling outcome of the scenario analysis and energy system modelling work behind the publication was that even in the latter part of the century when a net-zero carbon dioxide emissions state might be reached, electricity still only makes up ~50% of final energy. This means that 50% of final energy is something else!

The scenario presented shows a world that still requires several types of final energy to meet its needs. For example, liquid hydrocarbons still dominate in shipping and aviation, even as road passenger transport is hardly serviced by hydrocarbons at all. For road freight transport, a three way split has emerged between electricity, hydrocarbons and hydrogen.

Industry remains a large user of thermal fuels throughout the century, with key processes such as cement, chemicals and metallurgical process all dependent on their use for the foreseeable future. Electrification makes significant inroads to other types of industry, but this is far from universal. Hydrogen is a potential thermal fuel of the future, but processes might have to be modified significantly to make use of it. For example, it is possible for hydrogen to act as the reducing agent in iron smelting, but today this is a pilot plant scale research project.

Even the manufacture of hydrogen might take two routes, with competition through efficiency and cost determining the eventual winner. The first is the conversion of natural gas to make hydrogen, with the resulting carbon dioxide captured and geologically stored. Alternatively, hydrogen can be produced by electrolysis of water with renewable energy providing the necessary electricity.

Of course the continued use of fossil fuels to meet the needs of hydrocarbons in transport, industry and even power generation means extensive deployment of carbon capture and storage (CCS).

Meeting the aim of the Paris Agreement and achieving a balance between anthropogenic emission sources and sinks (i.e. net zero emissions) is a complex challenge and not one that can necessarily be serviced by wind and solar, or for that matter electricity, alone. Rather, we potentially end up with a more diverse energy system, much larger in scale than today, with a set of new processes (CCS), new industries (hydrogen based) and new sources (solar PV).

NZE Energy System Development

Pathways to Net-Zero Emissions

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Three years ago when Shell released their New Lens Scenarios, the two views of the future looked out far beyond previous scenarios, taking in the period from 2050-2100. This offered the opportunity for both scenarios to explore ways in which the world might reach a point of net-zero carbon dioxide emissions, down from some 40 billion tonnes per annum at the moment. Such an outcome is critically important for the global environment as it means stabilization and then probably some decline in atmospheric carbon dioxide levels, an essential requirement for limiting the current rise in surface temperature.

Net-zero emissions is also a requirement of the Paris Agreement. Article 4 is very clear in that regard, with its call;

“so as to achieve a balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases in the second half of this century. . . “

Energy scenarios typically explore the nearer term and many limit their horizon at 2050, but that isn’t sufficient for seeing truly profound changes in the energy system. These will play out on longer timescales, given the size of the system, the capital and capacity required to turn the system over. Solar energy is a good example. Today, we are in the middle of an apparent boom, but that is founded on years of development and improvement in the underlying technologies, a process that is still underway. Even at current deployment rates, solar still makes up only a small fraction of the global power generation system and electricity only represents 20% of the final energy we actually use. But over many decades, an energy technology such as solar PV may come to dominate the system.

Looking at the emissions issue from the fossil fuel side, even if solar was to dominate, would fossil fuels and the associated emissions of carbon dioxide necessarily decline? Simply building more renewables doesn’t guarantee such an outcome and even a significant reduction in fossil fuel use could still mean a continuing rise in atmospheric carbon dioxide, albeit at a reduced rate. Scenarios help explore such questions and by extending the New Lens Scenarios to 2100, real solutions to reaching net zero emissions present themselves.

The original “New Lens Scenarios” publication from 2013 focussed more on the period through to 2060, but a new publication released by Shell looks specifically at the challenge posed by net zero emissions and explores plausible pathways towards such an outcome using the “New Lens Scenarios” as a backdrop. I have been involved in the development and writing of this publication, which started in earnest only days after the Paris Agreement was adopted. But the material within it comes from the strong base built up over many years through the various Shell scenarios.

The analysis presented sees the energy system doubling in size as global population heads towards 10 billion people. Today we collectively consume about 500 Exajoules of energy; this could rise to some 1000 Exajoules by the end of the century. The makeup of that energy system will most likely look very different from today, but it is probably not a world without fossil energy; rather it is a world with net-zero carbon dioxide emissions. Carbon capture and storage therefore plays a significant role. Even in 2100, hydrocarbon fuels could still make sense for sectors such as aviation, shipping, chemicals and some heavy industry. Electrification of the energy system would need to shifted from ~20% today to over 50% during the century.

NZE Energy mix in 2100
The new supplement is called “A Better Life with a Healthy Planet. Pathways to Net-Zero Emissions”. The title highlights the intersection between the need for energy to meet the UN Sustainable Development Goals and the requirement of the Paris Agreement to reach net-zero emissions. A better life relies on universal access to energy. The publication comes with a wealth of online material to support it.

NZE Cover

Going below zero

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With the advent of the Paris Agreement, there is a new focus on net zero emissions. This is largely driven by a better understanding of climate science (the importance of cumulative emissions), but also by a line in the Agreement itself which calls for a ‘balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases in the second half of this century’. This potentially brings into play a set of technologies known as negative emissions technologies or NETs. A NET is a technology which draws down on atmospheric carbon dioxide; perhaps the simplest implementation of this is planting a tree.

NETs are required for two reasons over the long term;

  1. Be it local or global, a requirement for net zero emissions will inevitably mean a balance between remaining sources of emissions and the removal of carbon dioxide from the atmosphere as an offset, rather than a world of no emissions at all. Remaining sources of emissions could include some continuing use of fossil fuels but without dedicated carbon capture and storage (e.g. aviation) or very difficult to manage emissions such as from the agriculture sector. This requirement may only need NET deployment on a modest scale, simply to match the remaining emission sources. However, if those sources remain significant, then NET deployment would have to be scaled to match.
  2. At a global level, cumulative emissions may have exceeded a desired level for a certain temperature goal, in which case there is a need for an overall drawdown on atmospheric carbon dioxide, beyond that which natural sinks might deliver (e.g. continued ocean uptake). This is likely to require very significant deployment of NETs, certainly on the many gigatonnes per annum scale.

Even before the Paris Agreement, an in-depth look at the IPCC 5th Assessment report would have shown that many of the scenarios consistent with the 2°C goal included a period in the second half of the century when global emissions were negative to achieve a net drawdown on atmospheric carbon dioxide. The reason for needing such a period is that under these scenarios it doesn’t prove possible to limit emissions sufficiently, given the time it takes to re-engineer the energy system in the face of rising demand and legacy infrastructure.

The Paris Agreement has only strengthened the need for negative emissions technologies. With a goal of somewhere between 1.5 and 1.8C (‘well below’, as the Agreement states, could be interpreted as at least 10% below 2°C), the cumulative emissions of carbon should be some 175 billion tonnes of carbon lower than for a 2°C scenario, or 640 billion tonnes CO2. At current levels, that is the equivalent of 15 years emissions. As I illustrated in a pre-Paris post, decades of NET deployment and use may be required to meet this stringent carbon budget.

A recent article in Nature Climate (Biophysical and economic limits to negative CO2 emissions, Nature Climate Vol 6, January 2016) looks more deeply at the set of technologies that society may come to depend on in the coming decades. The article neatly categorises them with yet another set of acronyms (with OU, AS and BC ascribed by me);

  • BECCS: bioenergy with carbon capture and storage.
  • DAC: Direct air capture of carbon dioxide from ambient air by engineered chemical reactions. This would then become DACS (or DACCS) if geological storage were involved.
  • EW: Enhanced weathering of minerals, where natural weathering to remove carbon dioxide from the atmosphere is accelerated and the products stored in soils, or buried deep in land or deep-ocean.
  • AR: Afforestation and reforestation to fix atmospheric carbon ion biomass and soils.
  • OU: manipulation of carbon uptake by the ocean, either biologically or chemically.
  • AS: Altered agricultural practices, such as increased carbon storage in soils.
  • BC: Converting biomass to recalcitrant biochar, for use as a soil amendment.

The article focusses on BECCS, DAC, EW and AR and gives a detailed breakdown of the global impacts of these technology areas in terms of water, energy needs, land use and so on. It is clear that there is no silver bullet to rely on. While BECCS and DAC can potentially be deployed at scale and make a material difference to atmospheric carbon dioxide (>3 GT Carbon per annum by 2100, or 10+ GT CO2), BECCS requires significant land and water use (but is a net energy producer), whereas DAC is a big energy user. The latter is also deemed to be very expensive to implement. EW, on the other hand, just doesn’t make the grade in terms of scale. That leaves AR, which is certainly scalable but only very large scale deployment occupying huge swathes of land will make a significant difference in atmospheric carbon dioxide.

The paper ends with the rather sobering recognition that a failure of NETs to deliver expected mitigation in the future due to any combination of the biophysical and economic limits examined, leaves the world with no ‘Plan B’. Clearly there is much more to be done to commercialise and deliver a sustainable pathway for this family of technologies.

It’s all about the transition

The ambition embodied within the Paris Agreement argues for the need to reach a state of net zero anthropogenic emissions around the middle of the century, although the text of the Agreement is less stringent and points to the second half of the century for a balance between sinks and sources. Either way, this presents a formidable challenge.

Looking at a modern developed economy today, it is possible to imagine a state of much lower emissions, or even net-zero. The technologies to have a zero emission power sector are readily available and have been for some time; look at the level that nuclear power reached in France as early as the 1980s. Today we also have carbon capture and storage and scalable renewable energy. Vehicle electrification is now coming of age and it is not difficult to imagine a future where this dominates, with heavy transport potentially using hydrogen. Homes can also be electrified and the service sector / secondary industry economy that drives the developed world today is primarily electricity based.

But the manufacture of goods still represents a large part of the global economy. Material goods represent one facet of our economy and certainly one that is critically important in the early stages of development of most economies. For example, between 2004 and 2014 some 350 million refrigerators were produced and went into use in China with a further 250 million exported. Production in 2000 was just 12 million units. China is now the world’s 6th largest exporter (2014 by value) of refrigerators, but this is just one sixth of US refrigerator exports.

The same is true when it comes to the refining and fabrication of the raw materials that developed and developing country secondary industry requires. These products all demand considerable use of fossil fuels for combustion based processes such as smelting, refining, base chemical manufacture and similar. Nevertheless, we could perhaps imagine a world based on 3D printing using various exotic materials (graphene, certain polymers etc.) as the raw material for manufacture. But even in this world considerable chemical plant capacity and therefore process heat would be required to manufacture the printer feedstock, but carbon capture and storage could handle emissions from these sources.

China grew rapidly on the back of large scale manufacturing and at the same time it built vast swathes of infrastructure; from cities such as Shanghai and Chongqing to the high speed rail networks that now connect them. Between 1995 and 2015 cumulative emissions from China amounted to some 130 billion tonnes of carbon dioxide, or 100 tonnes per person. For the most part, this wasn’t for personal domestic use (i.e. home electricity and heating), but to make products for consumers in China and for export which in turn finances domestic infrastructure for the future. The process is far from complete, but China is already starting to look to other economies to make its raw materials and supply finished products as it attempts to develop its service sector.

The situation for the least developed economies is not dissimilar to China 30 years ago. Some 3 billion or more people live in circumstances where little or only modest levels of infrastructure exists. While they may now have basic renewable energy for lighting and some other services, their standard of living remains far below other parts of the world. The development pathway in front of them may well be similar to the one that China embarked on in the 1980s. That pathway might even be funded by products made for the Chinese economy as its service sector grows and energy use reaches a plateau or even falls slightly.

The 100 tonnes per person of development emissions is perhaps the hardest to decarbonise. It is from steel mills, cement plants, chemical plants, manufacturing industry and heavy goods transport. These are the backbone industries and services for development, many of which have long gone from developed economies. They may also be quite expensive to decarbonise, which is problematic for economies in the earlier stages of rapid development. This development also leads to a degree of lock-in as once industries are created and jobs are in place there is a strong desire to keep them; the recent concern as the last major UK steel plant shed more jobs is an example. The same industries are also needed to continue making a wide range of products, from cars to iPhones, for consumers in the rest of the world.

One particular challenge for post-Paris implementation of the Agreement is this 100 tonnes per person of development emissions and the lock-in that follows. While the net-zero goal looks feasible and can be imagined as a longer term outcome, the interim emissions bulge as development continues and the supporting industries required for infrastructure are put in place may take us well beyond 2°C rather than the goal of well below. Further to this, the energy demand that will be created just to fuel the energy transition itself could be significant as hundreds of lithium mines open, solar PV factories expand and new vehicle technologies are offered to the public.

Article 6 within the Paris Agreement makes mention of a Sustainable Development Mechanism that results in emissions reductions. Such a mechanism could be an important part of the solution set for this problem. More on that to follow.

The highlight of the Paris Agreement is without question the ambition embodied within it. This had its foundation with the Alliance of Small Island States (AOSIS) and their deep concern regarding future sea level rise. But the issue snowballed as the conference progressed, supported by a strong dose of techno-optimism that was prevalent throughout the halls of the Le Bourget Conference Centre. The text that was agreed upon is important, with the goal embodied in to distinct sections;

Holding the increase in the global average temperature to well below 2 °C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5 °C above pre-industrial levels, recognizing that this would significantly reduce the risks and impacts of climate change;

Parties aim to reach global peaking of greenhouse gas emissions as soon as possible, recognizing that peaking will take longer for developing country Parties, and to undertake rapid reductions thereafter in accordance with best available science, so as to achieve a balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases in the second half of this century . . .

In a post written before the conclusion of COP21, I assessed that a 1.5°C goal would require a rapid forty year transition to net-zero anthropogenic emissions and a period until at least the end of the century with negative emissions via BECCS (bioenergy and CCS) and DACCS (direct air capture and CCS). But the pathway proposed by the Agreement itself isn’t quite as ambitious, even while it aspires to a 1.5+°C outcome. Rather, it proposes achieving a balance between anthropogenic emissions and removals by sinks in the second half of the century. This may not be sufficient to achieve the 1.5+°C goal, with a key deciding element being the role of natural sinks.

The 1.5+°C pathway issue is highlighted in a paper published by the MIT Joint Program in July 2013. MIT deliberately avoided the use of negative emissions technologies, partly due to concerns about their scalability but also preferring to test the impact of natural sinks on the outcome. Of these, the ocean is the major short term sink because of the imbalance between levels of CO2 in the ocean and the atmosphere.

MIT analyzed four pathways that result in net zero anthropogenic emissions. These are shown in the chart below (fossil energy CO2 emissions only) against a business as usual trajectory based on the 2010 post-Copenhagen national pledges.

  1. An immediate drop to net zero by 2015, starting in 2010 (Natural only after 2015).
  2. A very rapid drop to net zero by 2035, but with growth from 2010 to 2030 (Natural only after 2035).
  3. A more extended drop to net zero by 2060, with the decline commencing in 2010 (Alternative).
  4. The IEA 450 scenario, with emissions peaking around 2020 and reaching net zero by 2070 (IEA 450).

MIT Scenarios - CO2 emissions

Pathway 3 is of particular interest. In this case anthropogenic emissions are at net zero by 2060, although starting to decline from 2010 when energy emissions are at 30 Gt CO2 per annum (it is now 2016 and they are at ~33 Gt). This scenario sees temperatures rise above 2°C by mid-century, but then decline as the ocean takes up significant quantities of CO2 from the atmosphere but with nothing being added from anthropogenic sources.  After some 20-30 years, as the ocean’s upper layer comes into balance with the atmosphere, uptake of CO2 slows. Mixing into the deep ocean is much slower but will continue for hundreds to thousands of years.

Back in 2010 the cumulative emissions from 1750 (to 2010) stood at some 532 billion tonnes carbon, which means that Pathway 3 approximates a 1.5°C outlook as the area under the curve from 2010 to 2060 (energy, cement and land use) represents an additional 250 billion tonnes of carbon emissions, giving a total of some 780 billion tonnes. The relationship between carbon emissions and temperature is about 2°C per trillion tonnes. The chart below shows the modelled pathway which results in an end-of-century temperature rise of 1.5°C.

MIT Scenarios - Temperature

The natural sink is therefore very important, offering some 0.5°C (see the light blue line in the chart above) of temperature reduction following an overshoot. This is possibly the only way in which 1.5°C can be met,  although significant anthropogenic sinks may also be developed (including reforestation) later which could offer the same drawdown. As such, with the Paris Agreement potentially not making use of this and instead only providing for emissions to fall to a level which matches the ability of sinks to take up carbon emissions, the task of meeting 1.5°C becomes considerably more difficult.

The same is true of the IEA 450 Scenario. With 2010 now behind us, the future equivalent of the Alternative pathway which saw reductions from 2010 onwards is probably the red 450 line (reductions from 2020), which overshoots to 2.7°C before achieving something of a plateau at 2°C. But to bring this down further by the end of the century and therefore comply with the Paris Agreement would also require the major application of anthropogenic sinks, such as via CCS and rapid reforestation.

This discussion may be something of a moot point today because the job of rapidly reducing emissions hasn’t even started and arguably we have at least 40+ years to think about where the endpoint should be. Nevertheless, as nations begin to reflect on the Paris outcome in the coming months and relook at their respective reduction pathways, the long term end point does become relevant because energy infrastructure planning requires a multi-decadal outlook. In its initial formulation of a long term carbon budget, the UK did need to look forward to 2050 but that was from a 2008 starting point. With a new starting point of 2020 or thereabouts, a 2060 or even 2070 end-point may well be considered.

There is of course a disturbing flip side to this story – continued rapid uptake of CO2 by the ocean also gives rise to increasing levels of ocean acidification.

COP21: A Pathway for 1.5°C

The case for limiting the rise in global temperatures to 2°C was made many years ago and finally agreed at COP16 in Cancun in 2010. But the text noted the importance of an even more aggressive target, notably 1.5°C, proposed by the small island states who were deeply concerned about future sea level rise. While 1.5°C doesn’t guarantee to limit sea level rise such that certain island nations remain safe, it does further shift the global risk profile in terms of possible major changes in the ice shelves.

The idea of a 1.5°C goal has remained largely in the background since 2010, but COP21 has brought the issue to the forefront of negotiators minds, with a reported group of some 100 countries now willing to support such an objective. At a reception early in the second week, the UK Climate Minister was very upbeat about the 1.5°C goal and the government’s role in working with AOSIS (Alliance of Small Island States). At the COP Plenary on Wednesday night (9th December), many groups and nations spoke about the need for a 1.5°C goal.  But while there is increasing enthusiasm for and talk about such a goal, there seems to be limited substantive discussion on the feasibility of achieving it.

As often discussed in my postings, the expected global temperature rise is closely linked with cumulative emissions over time, not the level of emissions in a certain year. This means that what might have seemed achievable in 2010, is all the more difficult in 2015 with higher emissions and continued upward pressure. In fact, between 2010 and 2015 another 60 billion tonnes of carbon has been released into the atmosphere. Total emissions since 1750 now stand at just under 600 billion tonnes carbon, with 1.5°C equivalent to some 750 billion tonnes carbon based on a climate sensitivity of 2°C per trillion tonnes. Even if emissions were to continue to plateau as we have seen over 2014-2015, the 1.5°C threshold would be reached as early as 2028.

There are always a variety of trajectories possible for any temperature goal, but 1.5°C offers little room for flexibility, given its stringency. One such pathway which adds up to ~750 billion tonnes carbon by 2100 is shown below (global CO2 emissions on the vertical scale). In this pathway, global net zero emissions must be reached in just 40 years (860 billion tonnes accumulation), followed by another half century of atmospheric carbon removal and storage (~100 billion tonnes removal). Some 10 billion tonnes of CO2 must be removed and stored each year by late in the century, either through bio-energy with carbon capture and storage (BECCS) or direct air capture of CO2 and subsequent storage (DACCS). Significant reforestation would also play a major role. With infrastructure in place, the 22nd century might even offer the possibility of drawing down on CO2 below a level that corresponds with 1.5°C.

OnepointfiveC

Apart from massive reliance on CCS both on the way to net zero emissions and afterwards to correct the over accumulation, such a plan would require a complete rebuild of the energy system in just 40 years. This would include the entire industrial system, all transport and power generation. Alternatives would have to be found for many petroleum based products and a new large scale synthetic hydrocarbon industry would be needed for sectors such as aviation and shipping. While agriculture is largely a bio based emissions system, a solution to agricultural methane emissions would also nevertheless be needed.

A pathway that doesn’t involve future use of CCS would require net zero emissions in just 23 years – an option that isn’t even remotely feasible. Returning to the 40 year pathway, even this presents an immensely challenging task. While it might be feasible to have a zero emissions power sector in under 40 years, particularly given that all the necessary technologies to do so exist in one form or another, electricity still represents only 20% of final energy use. Solutions would have to be found for all other sectors, which in many instances involves electrification and therefore places a significant additional load on the redevelopment of the power generation system. Aviation would be particularly tricky.

Finally, there is CCS itself. The pathway above (and almost any other 1.5°C pathway) is completely dependent on it, yet the technology is hardly deployed today. It is certainly commercially ready, but the barriers to deployment are many, ranging from the lack of an economic case for project development to public concern about deep storage of carbon dioxide. The later that net zero emissions is reached, the greater the post net zero dependence on CCS becomes.

While the case for 1.5°C has certainly been made from a climate perspective, it has yet to be demonstrated from an implementation perspective.

COP21: Targets, goals and objectives

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As the negotiators struggle on in Paris at COP21, the question of the long term goal has emerged. What should it be, how should it be structured and will it send the necessary signal to drive future national contributions.

The idea of a goal goes back to the creation of the UNFCCC. There is the original text agreed when the Convention was first written in 1992, i.e. “. . . stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system . . . “. At COP16 in Cancun, the Parties to the UNFCCC reformulated this as a numerical goal; the need to limit warming of the climate system to no more than 2°C above the pre-industrial level with consideration for reducing this to 1.5°C as the science might dictate. This seems very clear, but in fact offers little immediate guidance to those attempting to establish a national or even global emissions pathway.

The climate system is a slow lumbering beast and the global temperature could take years or even decades to settle down once there is stabilization of carbon dioxide (and other greenhouse gases) in the atmosphere. It could be decades after that before we are collectively sure that no further temperature rises will take place. But the science has shown that the eventual rise in temperature is strongly related to the cumulative emissions of carbon dioxide over time, starting when emissions were negligible (say 1750) and running through several centuries (e.g. to 2500). Myles Allen et. al. from Oxford University equated 2°C to the cumulative release of one trillion tonnes of carbon, which offers a far more mechanistic approach to calculating the point at which 2°C is reached. So far, cumulative emissions amount to some 600 billion tonnes of carbon. However, even this approach has uncertainty associated with it in that the actual relationship between cumulative emissions and temperature is not precisely known. If emissions stopped today, it is very unlikely (but not a zero chance) that warming would continue to above 2°C, but if emissions were to stop when the trillion tonne threshold is reached then there is only a 50% chance that the temperature would stay below 2°C. The agreement in Cancun doesn’t cover uncertainty.

The Oxford University team have developed a website that counts carbon emissions in a bid to familiarize people with the concept. As of writing this post, it was counting through 596 billion tonnes and provided an estimate that 1 trillion tonnes will be reached in October 2038. The INDCs already reach out to 2030 and as they stand, will not put the necessary dent into the global emissions profile that is needed to avoid passing one trillion tonnes. In terms of energy system development, 2038 is in the medium term. Most forecasts out to this period, including the IEA New Policies Scenario which factor in the INDCs, show energy demand and emissions rising over that period, not falling.

In line with the Cancun Agreement, a number of Parties have maintained the need to lower the goal to 1.5°C, but particularly those from low lying island states who are justifiably concerned about long term sea level rise. This goal is being voiced more loudly here in Paris. Using the relationship developed by Allen et. al., this implies that 1.5°C would be exceeded if cumulative carbon emissions passed 750 billion tonnes, which could happen as early as 2027. This would imply a massive need for atmospheric CO2 capture and storage over the balance of the century for the simple reason that cumulative emissions could not be contained to such a level by energy system reductions alone.

More recently the concept of net zero emissions (NZE) has emerged. This is the point in time at which there is no net flow of anthropogenic carbon dioxide into the atmosphere; either because there are no emissions at all or if emissions remain because they are completely offset with a similar uptake through carbon capture and storage or reforestation and soil management. Emissions are likely to remain for a very long time in sectors such as heavy transport, industry and agriculture. NZE has been closely linked to 2°C, but in fact any temperature plateau, be it 1.5°C or even 4°C requires NZE. If not, warming just continues as atmospheric CO2 levels rise. There is now a discussion as to when NZE should be reached – as early as 2050 (but practicality must be a consideration), or perhaps by the end of the century. However, what is actually important is the area under the emissions curve before NZE is achieved, less the area under the curve after it is reached, assuming emissions trend into negative territory with technologies such as direct air capture or bioenergy with carbon capture and storage (DACCS or BECCS). The date at which NZE is reached is important, but not necessarily an indicator of the eventual rise in temperature. Just to complicate matters further, although the world needs to achieve NZE eventually, it may be the case that net anthropogenic emissions do not have to be zero by 2050 or 2100 to meet the 2°C  goal because of carbon removal arising from natural sinks in the oceans and terrestrial ecosystems.

Other proposals put forward by Parties and some observers simply call for an urgent peaking of emissions. This is important as well, but again it doesn’t tell the full story. What happens after the emissions peak is critical. A long slow decline to some plateau would be positive, but unless that plateau is close to NZE, then cumulative emissions continue to build, along with the associated warming. Other proposals argue for emissions to be at some reduced level by 2050, which presumes a certain follow-on trajectory equating to 2°C or thereabouts.

Where the Parties land in this discussion remains to be seen, but with only days left and the complexity of goal setting becoming apparent, this may end up being an issue for the years ahead rather than one that can be fully resolved in Paris in a week. 2°C may have to do for now.

Emission pathway

 

Why carbon pricing matters – the video

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David+2

And now for something completely different

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The Carbon Sequestration Leadership Forum (CSLF) held its 6th Ministerial Meeting in Riyadh, Saudi Arabia recently. The conference offered considerable opportunity for governments and companies to showcase their achievements in carbon capture and storage (CCS) and to highlight areas in which research and development was proceeding.

Given the location, Saudi Aramco was there in force and they also offered the opportunity for a number of participants to visit their headquarters in Dhahran and get an even deeper look at how the company was looking at the CO2 issue and the use of CCS. As there isn’t a carbon pricing system operating in Saudi Arabia, the company is heavily focussed on using CO2 for Enhanced Oil Recovery (EOR), but this is at least driving research and development on CO2 separation, purification and transport with a view to further lowering the cost and improving the efficiency of these key steps in the CCS value chain.

To this end, Saudi Aramco is doing some intriguing work on small scale carbon capture, which was demonstrated in both Riyadh and Dhahran by their display featuring a saloon car with on-board carbon capture. The vehicle captures about thirty percent of the carbon dioxide in the exhaust, using a solvent process. The CO2 is then recovered from the solvent, compressed and stored as a supercritical liquid in a small cylinder, all within the vehicle itself. The carbon dioxide can then be discharged when the car is filled with fuel as part of the normal service offered at a (future) gasoline station. The fuel supplier would then handle long term geological storage of the carbon dioxide or may have outlets where it can be profitably used (e.g. as a feedstock for manufacture of more fuel, but with the caveat that a considerable amount of energy will be required for such a step).

CCS Car (small)

The vehicle is a 2nd generation prototype, with the carbon capture equipment occupying about half the boot space. But this is a huge step forward compared to their first generation attempt where the equipment sat on a trailer pulled by the car. Further enhancements are planned. The current system is an active one, in that it draws energy from the vehicle to operate the equipment, resulting in an efficiency penalty of about 5-10% for the vehicle as a whole. Future thinking includes a more passive system, which could see carbon dioxide absorbed into a chemical matrix such as in a regular catalytic convertor. However, some energy input would presumably be required at some point to release this for subsequent use or storage.

Whether this ends up as a viable domestic vehicle solution is not entirely the point at this stage. One aspiration that the demonstration alluded to was its use in Heavy Goods Vehicles (HGV) which travel long distances with large loads and where battery technology may not be feasible. Other applications could be imagined, such as on board ships. More importantly, the underlying development of smaller and cheaper carbon capture technology offers real hope for long term management of emissions. It was also clear that this work and the other efforts being made by Saudi Aramco on CCS and EOR have very high level support in the country; the Saudi Minister of Petroleum and Mineral Resources, Ali Al-Naimi, spent two full days both at the conference and escorting the smaller group to Dhahran.

Al-Naimi

One million tonnes of CO2

The first week of November sees Shell officially open its first major carbon capture and storage (CCS) facility, the Quest project. It is in Alberta, Canada and will capture and store about one million tonnes of carbon dioxide per annum. Construction commenced back in September 2012 when the Final Investment Decision (FID) was taken and the plant started up and began operating for the first time in September of this year, just three years later. It is one of only a handful of fully integrated carbon capture and storage facilities operating globally. There are now many facilities that capture CO2 but mainly linked to Enhanced Oil Recovery which provides an income source for these projects.  Quest has dedicated CO2 storage, developed in an area some 65 kms from the capture site at a depth of about 2 kms.

Quest Construction

The Quest income source is not based on EOR; it has been able to take advantage of the government implemented carbon price that prevails within Alberta. Although the current carbon pricing mechanism has an effective ceiling of $15 per tonne CO2 which isn’t sufficient for CCS, let alone a first of its kind, it nevertheless provides a valuable incentive income to operate the facility which has been built on the back of two substantial capital grants from the Provincial and Federal governments respectively. A supplementary mechanism also in place in Alberta provide credits related to the carbon price mechanism for the early years of a CCS project, providing additional operating revenue for any new facility.

Canada, as it turns out, has become a global leader in CCS. The Quest facility is the second major project to be started up in Canada is as many years, with the Saskpower Boundary Dam project commencing operations this time last year.

As noted, Quest will capture and store approximately one million tonnes of carbon dioxide per annum. It demonstrates how quickly and efficiently large scale CO2 management can be implemented once the fiscal conditions are in place. Quest, which is relatively small in scale for an industry that is used to managing gas processing and transport in the hundreds of millions to billions of tonnes globally, demonstrates both the need for continued expansion of the CCS industry and the importance of carbon pricing policy to drive it forward. This single facility far surpasses the largest solar PV facilities operating around the world in terms of CO2 management. Take for example the Desert Sunlight Solar Farm in California, currently the fourth largest solar PV power station in the world. According to First Solar, it displaces 300,000 tonnes of CO2 annually, less than a third of that captured and permanently stored by Quest.

A key difference though is the use of the word displace. Alternative energy projects don’t directly manage CO2, they generate energy without CO2 emissions. But, as I have noted in previous postings and in my first book, the release of fossil carbon to the atmosphere is more a function of energy prices and resource availability. This means that even when a project like Desert Sunlight operates, the CO2 it notionally displaces may still be released at some other location or at some other time, depending on long term energy prices and extraction economics. There is no doubt that the CO2 is not being emitted right now in California, but that doesn’t necessarily resolve the problem. Quest, by contrast, directly manages the CO2 from fossil fuel extraction.

The requirement to provide alternative energy (i.e. without CO2 emissions) needs to grow, but we shouldn’t imagine that such action, by itself, will fully resolve the climate issue. That will come through the application of carbon pricing mechanisms by governments, driving the further expansion of both the alternative energy and CCS industries as a result.

A video about the Quest project, made by the constructors, Fluor, is available here.