Seven Years On

The last seven year have seen too little progress on solving the climate change problem, despite some welcome developments.  Much more rapid progress is now needed.

It is now seven years since I started this blog – my first post was on 3^rd March 2013.  It seems a good time to take a look at what has gone well and what has gone badly over that period in efforts to reduce climate change.  So here are seven ways in which things have gone badly, and seven ways in which they have gone well.

Things that have gone badly over the last seven years

1. Annual CO₂ emissions from energy and industry have increased over the last seven years, continuing the long-term trend, when they need to be decreasing rapidly.

Chart 1: Emissions of CO₂ from energy and industry (excluding land use)

Source: EDGAR  https://edgar.jrc.ec.europa.eu/booklet2019/Fossil_CO2andGHG_emissions_of_all_world_countries_booklet_2019report.pdf

2. Deforestation has not fallen – if anything it’s increased.

This not only bad for the climate, it’s bad for biodiversity and the wider stability of ecosystems.

Chart 2: Tropical primary forest loss (million hectares)

See:  https://www.bbc.co.uk/news/science-environment-48104037

3. Over 15% of the remaining carbon budget has been used since 2013, even on the most optimistic view[i].

In 2013 the remaining carbon budget (that is, total cumulative CO₂ emissions that remain possible while limiting global mean surface temperature rises to 2 degrees) was around 1900Gt CO₂.  It is now around 1600Gt CO₂.The remainder is getting used up ever more quickly as emissions continue to rise.

4. Large amounts of high carbon infrastructure are still being built.

This includes large amounts of new coal-fuelled power generation. This risks lock-in of emissions for decades.

5. There is a lack of progress with developing and implementing low carbon technologies in many sectors

Most emissions intensive industries, notably steel, have made little progress in changing their processes to reduce emissions.  One of the main technologies likely to be needed for decarbonising industrial emissions, CCS, has seen very little deployment, with only about an additional 10 mtpa[ii] stored from projects coming on line since 2013.  The largest contributor to the increase has been the Gorgan project, which is natural gas production, so not likely to be part of a net zero emissions world.  10 mtpa is only about 0.02% of global emissions.  CCS is also likely to be essential for achieving negative emissions from Bioenergy with CCS (BECCS), among other things.  There has also been only very limited progress to date on deploying low carbon hydrogen.

6. China appears to be making emissions reduction less of a priority.

Among other factors, recently slowing economic growth seems to have focussed attention in China towards economic stability and energy security rather than the threats from climate change.

7. Most countries have targets that are far too weak

Existing pledges under the Paris Agreement imply a continuing increase in global emissions rather than the rapid decrease that is needed[iii].

This is a daunting list of problems.  However, there is also some good news, although in all cases it would be even better if positive trends were happening faster.

Good news from the last seven years

1. Costs of low carbon technologies have fallen rapidly, and continue to fall.

Wind and solar electricity are in many cases now competitive with, and often cheaper than, electricity from new fossil fuel generation.  Falling battery costs will enable to the electrification of surface transport and help balance the grid.

This seems to me to be by far the greatest cause for optimism.  Low carbon options will simply become the default choice for new investment in many cases, and policies to reduce emissions will increasingly be working to support a trend that is driven by economic as well as environment imperatives.

2. Some countries have put binding targets in place for net zero emissions.

The UK already has such a target for 2050, seeking to end the UK’s contribution to climate change.  The EU seems likely to formalise a similar target very soon.

3. Some countries have cut emissions significantly, showing what can be done.

The UK has cut its annual emissions by nearly 20% since 2013[iv], with the largest component of this being a reduction in coal use in the power sector, a change readily replicable elsewhere.

4. Public concern about climate change has risen while scepticism about the science has largely disappeared, at least outside the USA and a few other countries.

85% of UK voters are now concerned about climate change[v] with over a quarter ranking it among their top three issues[vi].  This was reflected during the recent general election campaign[vii] in all parties offering policies to reduce emissions to net zero .  Over time this should create the political space for some of the more challenging policies that will be needed to reduce emissions to close to zero.

5. Additional policies are being put in place, and carbon pricing is increasingly widespread.

For example, almost all major economies now have renewables targets, and there are over 50 carbon pricing systems in place around the world.

6. Governments increasingly see economic opportunities in decarbonisation rather than costs.

The opportunities created by new industries are increasingly recognised as part of wider industrial policy.

7. The Paris Agreement has been signed.

Almost all countries have now committed to limit temperature rises to below 2 degrees and to make a contribution to reaching that target, recognising different national circumstances.  Some may consider this is the main piece of good news over the past seven years.  However its effectiveness remains to be proven, and its success looks likely to depend on some of the other trends I’ve highlighted, notably falling costs for low carbon technologies.

Looking at these trends together, I am both less optimistic and more optimistic than I was in 2013.  I am less optimistic because seven years of rising emissions and continuing investment in high carbon infrastructure have made the challenge of limiting climate change even greater than it was.  But I am more optimistic because there is greater recognition and acceptance of the problem, more is now being done (though still nowhere near enough) and, above all, because low carbon energy is rapidly becoming cheaper than high carbon energy.  As a result it looks likely that emissions from the energy sector will eventually be greatly reduced and even halted entirely.  This may make it easier to focus on reducing other emissions as well, especially those from deforestation.

But eventually will be too late.  Much damage is already being done to our world.  More will inevitably follow. This will include the loss of irreplaceable parts of the natural world.  Given rising emissions, and how much of the carbon budget has been used up, it now looks practically impossible to keep temperature rises to 1.5 degrees, and difficult, though still possible, even to limit them to 2 degrees.

However it could still get much worse.  The task now is to avoid the worst of the risks by keeping emissions and accompanying temperature rises as low as possible, including keeping global temperature rises to below 2 degrees.  With a lot of effort and a little luck there is still time (just) to achieve this.  But the task has never been greater or more urgent.

Adam Whitmore – 9^th March 2020

[i] For a 50% chance of remaining below 2 degrees, based on cumulative CO₂ emissions.  See https://onclimatechangepolicydotorg.wordpress.com/2018/10/

[ii] https://www.globalccsinstitute.com/resources/global-status-report/

[iii] https://climateactiontracker.org/global/cat-emissions-gaps/

[iv] https://www.theccc.org.uk/publication/reducing-uk-emissions-2019-progress-report-to-parliament/

[v] https://www.ipsos.com/ipsos-mori/en-uk/concern-about-climate-change-reaches-record-levels-half-now-very-concerned

[vi] https://www.bbc.co.uk/news/science-environment-50307304

[vii] https://onclimatechangepolicydotorg.wordpress.com/2019/11/25/the-uks-political-consensus-on-climate-change/

 

Hydrogen and heat pumps may both play a role in UK building heating

Low carbon hydrogen and electricity via heat pumps may both play a large role in decarbonising building heating in the UK.  Ways forward are needed that maintain optionality around solutions while more is learnt about the right mix.

Decarbonising building heating in the UK poses a range of challenges.  First, the required transition is very large scale.  There are around 27 million households in the UK, with many more commercial buildings, small and large.  This implies around a million or more premises a year on average need to be converted to low carbon heat between now and 2050.

Along with scale, there is cost.  Replacing the UK’s heating system is expensive both in total and by household, even if the existing natural gas network can be used for hydrogen.   This challenge is made more difficult by the high seasonality of heating demand (Chart 1).  Building natural gas supply chains, reformers to produce hydrogen from natural gas, CCS, low carbon electricity and heat pumps all involve major capital investment.  Running this for only part of the year – the colder months – increases unit costs substantially. The chart below shows daily gas and electricity demand from non-daily metered (i.e. small) customers.  Demand for energy from gas, the major source of building heating at present, is about two or three times electricity demand during winter, and is much more seasonal.

Chart 1: Heating demand is highly seasonal …

Source: BEIS (2018) ‘Clean Growth – Transforming Heating’ https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/766109/decarbonising-heating.pdf

Furthermore, the transition to low carbon heat needs to be made largely with the UK’s existing building stock, which is mainly old and often badly insulated.  Improved insulation is a priority in any programme, but there are practical and cost constraints on what can be done with existing buildings.  (Buildings also need to be able to cope with the increased prevalence of heat waves as the climate warms, but that is a separate topic.)

Finally, building heating directly affects people’s day to day lives, so consumers’ acceptance is critical.  On the whole the present system, based mainly on natural gas boilers, works quite well except for its emissions.  Any new system should preferably work as well or better.

The leading candidates for low carbon heating in buildings are electricity, almost certainly using heat pumps to increase efficiency, and low carbon hydrogen.  Biomass seems unlikely to be available either at the scale or cost that would be needed for it to be a major contributor to low carbon heating, though it may find a niche.  District heating networks require low carbon heat and this must draw on the same ultimate set of sources of heat.  Waste heat from nuclear, once discussed as a possibility, no longer seems likely to be either practical or cost effective.

Recently the Committee on Climate Change (CCC) analysed the costs of decarbonising heat in 2050 using different approaches.  They looked at electricity, hydrogen, and combinations of the two.  The analysis concluded that a 50% increase over current costs was likely (Chart 2).  The remarkable thing about the analysis is that this cost was similar for all of the options considered.  Any differences were well within the uncertainty of the estimates.

Chart 2: Costs of different modes for decarbonising building heating …

Source:  Committee on Climate Change

With no large cost difference leading to one or the other option being preferred there is a need to test each option out to see which works better in practice.  Mixed solutions may be appropriate in many cases.  For example, hydrogen may be useful in providing top-up heat even if heat pumps are providing the baseload, or may be the only solution for some poorly insulated properties for which heat pumps don’t run at high enough temperatures.

The CCC’s analysis includes expected cost savings.  The transition to low carbon heat will clearly be more acceptable if this cost can be reduced further.  In particular there seem likely to be both technical advances and large economies of scale in heat pump manufacture and installation, and the costs of low carbon power may fall by more than assumed by the CCC.  As the analysis stands, a 50% increase is clearly politically difficult, especially when there do not seem to be advantages for the customer, and potentially some drawbacks.  However, this is less than a 2% p.a. compound increase in real terms over a 30 year period, which might be politically feasible if introduced gradually and spread across all consumers.

With such large changes in demand between summer and winter, seasonal storage is a major issue for reasons of both cost and practicality.  This is an under-researched area, and needs further work.  There are various possibilities – storage of hydrogen itself in salt caverns, storage of hydrogen as ammonia or storage of heat in ground sinks, but each has its problems and the scale involved is very large.

A final uncertainty is the form which hydrogen production will take.  At the moment methane in reformers predominates and, with the addition of CCS, may continue to do so.  However both the costs of low carbon electricity and of the electrolysis are decreasing rapidly.  Over the long term this may become a more significant pathway for hydrogen production.

These uncertainties imply that building heating poses a particularly difficult set of choices for policy.  It is not clear what route, or mix of routes, is the right one.  The transition needs to be quite rapid relative to the lifetimes and scale of existing infrastructure, and it involves the need for consumer acceptance.  There are also potentially strong network and lock in issues.

The best approach is likely to be to develop several types of solution in parallel, maintaining optionality while learning, and being prepared for some approaches to be dead ends.  The implications of this include the need for roll out of low carbon heat sources in some districts now to get an idea of how they will work at scale.

Some of this is happening, much more is needed.

Adam Whitmore -29^th October 2019.

 

Comparison of cost estimates with previous analysis by this blog.

Around four and a half years ago I looked at the costs of decarbonising domestic heating in the UK in winter using low carbon electricity.  I concluded that switching to low carbon heat would add 75% or more to domestic heating bills, with some drawbacks for consumers (I also looked at higher cost case, but this case no longer seems likely due to the fall in the costs of low carbon electricity, especially offshore wind, since the analysis was done.)  I suggested that this meant that the transition would be difficult and that reductions in capital costs were necessary.

This analysis is broadly consistent with the CCC analysis quoted here, which suggests a 50% increase on current costs.  The estimates are roughly similar given the large uncertainties involved , the inevitable differences is assumptions, and different basis of the estimates.  In particular the CCC analysis factors in reductions in costs of low carbon heating likely by 2050, whereas my previous analysis was based on current costs to make the point that cost reductions are necessary,  Consequently it would be expected that the CCC analysis would show a smaller cost increase relative to current costs.  Also, the CCC’s analysis may exclude some costs – estimates such as these have a tendency to go up when you look at them more closely.  Equally it may understate the cost reductions possible over decades.

 

 

How well is the UK on track for zero emissions by 2050?

By 2020 the UK will have very nearly halved its emissions over 30 years.  Reducing emissions by the same amount over the next 30 years will get the UK very close to zero.  However this will be very much more difficult.

A robust net zero target has been recommended for the UK …

A recent report by the UK’s Committee on Climate Change (CCC), the Government’s official advisory body, recommends that the UK adopts a legally binding target of net zero emissions of greenhouse gases by 2050[i], that is remaining emissions must be balanced by removal from the atmosphere.  If the Government agrees, this will be implemented by amending the reduction mandated by the Climate Change Act, from an 80% reduction from 1990 to a 100% reduction.

The target has several features that make it particularly ambitious.  It:

• sets a target of net zero emissions covering all greenhouse gases;
• includes international aviation and shipping;
• allows no use of international offsets; and
• is legally binding.

This is intended to end the UK’s contribution global warming.  It has no precedents elsewhere, although in France a bill with comparable provisions is under consideration[ii].

Progress to date has been good …

The UK has made good progress so far in reducing emissions since 1990.  Emissions in 2018 were around 45% below 1990 levels, having reduced at an average rate of about 12.5 million tonnes p.a. over the period.  On current trends, over the thirty years from 1990 to 2020 emissions will be reduced to about 420 million tonnes p.a., 47% below their 1990 levels.  Emissions will thus have nearly halved over the 30 years 1990 to 2020, half the period from 1990 to the target date of 2050.

Chart 1 shows how the UK’s progress compares with a linear track to the current target of an 80% reduction, to a 95% reduction and to a 100% reduction.  (For simplicity I’m ignoring international aviation and shipping).  The UK is currently on a linear track towards a 95% reduction by 2050.

Chart 1: Actual UK emissions compared with straight line progress towards different 2050 targets

 

Source: My analysis based on data from the Committee on Climate Change and UK Government.  Data for 2018 is provisional[iii]

The largest contributor to the total reduction so far has been the power sector.  Analysis by Carbon Brief[iv] showed that the fall in power sector emissions has been due to a combination deploying renewables, which made up about of third of generation in 2018, reducing coal use by switching to natural gas, and limiting electricity demand growth.

Industrial emissions have also fallen significantly.  However some of this likely represents heavy industry now being concentrated elsewhere in the world, so likely does not represent a fall in global emissions.  Emissions from waste have also fallen, due to better management.

Reducing emissions will be relatively easy in some sectors …

There are also reasons for optimism about continuing emissions reductions.  Many technologies are now there at scale and at competitive prices, which they were not in previous decades.  For example, falling renewables costs and better grid management, including cheaper storage, will help further decarbonisation of the power sector.  Electrification of surface transport now appears not only feasible, but likely to be strongly driven (at least for cars and vans) by economic factors alone as the cost of batteries continues to fall.

But huge challenges remain …

Nevertheless important difficulties remain for complete decarbonisation.

CCS is identified by the report as an essential technology.  However, as I have noted previously, it has made very little progress in recent years in the UK or elsewhere[v].  CCS is especially important for decarbonising industry.  This includes a major role for low carbon hydrogen, which is assumed to be produced from natural gas using CCS – although another possibility is that it comes from electrolysis using very cheap renewables power, e.g. at times of surplus.  CCS also looks to be necessary because of its use with bioenergy (BECCS), to give some negative emissions, though the lifecycle emissions from this will require careful attention

Decarbonising building heating, especially in the residential sector, continues to be a challenge.  The report envisages a mix of heat pumps and hydrogen, perhaps in the form of hybrid designs, with heat pumps providing the baseload being topped-up up by burning of hydrogen in winter.  I have previously written about the difficulties of widespread use of heat pumps[vi], and low carbon hydrogen from natural gas with CCS is also capital intensive to produce and therefore expensive to run for the winter only.  The scale of any programme and consumer acceptance remain major challenges, and the difficulties encountered by the UK’s smart meter installation programme – by comparison a very simple change – are not an encouraging precedent.

Emissions from agriculture are difficult to eliminate completely, and no technologies are likely to be available by 2050 that enable aviation emissions to be completely eliminated.  This will require some negative emissions to balance remaining emissions from these sectors.

Policy needs to be greatly strengthened …

Crucially several of the necessary transformations are very large scale, and need long lead times, and investment over decades.  There is an urgent need to make progress on these, and policy needs to recognise this.  This includes plans for significant absorption from reforestation, as trees need to be planted early enough that they can grow to be absorbing substantial amounts by 2050.

The UK’s progress on emissions reduction so far has been good, having made greater reductions than any other major economy[vii].  And technological advances in some areas are likely to enable substantial further progress.  However much more is needed.  In particular policy needs to look now at some of the difficult areas where substantial long-term investment will be needed

Adam Whitmore – 22^nd May 2019

 

 

[i] https://www.theccc.org.uk/2019/05/02/phase-out-greenhouse-gas-emissions-by-2050-to-end-uk-contribution-to-global-warming/

 

[ii] The CCC report notes that Norway, Sweden and Denmark have net zero targets, but they allow use of international offsets (up to 15% in the case of Sweden).  France has published a target similar to the UK’s in a bill.  The European Commission has proposed something similar for the EU as a whole, but this is a long way from being adopted. California has non-legally binding targets to achieve net zero by 2045.  Two smaller jurisdictions (Costa Rica, Bhutan) have established net zero targets but these are expected to be achieved mainly by land use changes.  New Zealand has a draft bill to establish a target, but eliminating all GHGs will be difficult because of the role of agriculture in the New Zealand economy.

 

[iii] https://www.gov.uk/government/statistics/provisional-uk-greenhouse-gas-emissions-national-statistics-2018  The change from 2017 to 2018 is applied to the data series from 1990 produced by the CCC (the two data series differ very slightly in their absolute levels).

 

[iv] https://www.carbonbrief.org/analysis-uk-electricity-generation-2018-falls-to-lowest-since-1994

 

[v] https://onclimatechangepolicydotorg.wordpress.com/2018/04/25/a-limited-but-important-medium-term-future-for-ccs/

 

[vi] https://onclimatechangepolicydotorg.wordpress.com/2015/05/18/reducing-the-costs-of-decarbonising-winter-heating-needs-to-be-a-priority/

 

[vii] https://onclimatechangepolicydotorg.wordpress.com/2017/05/09/uk-emissions-reductions-offer-lessons-for-others/

 

Underestimating the contribution of solar PV risks damaging policy making

A brief update on this post can be found here https://onclimatechangepolicydotorg.wordpress.com/2019/01/21/the-ieas-solar-pv-projections-are-more-misleading-than-ever/

Underestimating the contribution of solar PV risks damaging policy making

The continuing lack of realism in projections for solar PV risks damaging policy making by misdirecting effort in developing low carbon technologies.

Solar PV continues its remarkable growth …

Electricity generation from solar PV continues to grow very rapidly.  It now supplies over 1% of global electricity consumption and this proportion looks set to continue growing very rapidly over the next decade as costs continue to fall.

Chart 1 Rapid growth of solar PV generation continues

Sources: BP statistical review of world energy [i].  1% of consumption based on data for generation with an adjustment for losses.

Many studies have underestimated this growth and continue to do so …

This growth has been much faster than many predicted.  In 2013 and again in 2015  I noted[ii] that the IEA’s annual World Energy Outlook (WEO) projections for both wind and solar PV were consistently vastly too low.  Specifically, the IEA’s projections showed the annual rate of installation of wind and solar PV capacity remaining roughly constant, whereas in fact it both were increasing rapidly.  Updated analysis for solar PV recently published by Auke Hoekstra[iii] shows that this position seems remarkably unchanged (see Chart 2).  The repeated gross divergence between forecasts and outturns over so many years makes it hard to conclude anything other than the IEA is showing a wilful disconnection with reality in this respect, though their historical data on the energy sector remains very valuable.

Chart 2:  IEA projections for solar PV capacity continue to vastly underestimate growth

Although the IEA’s projections are particularly notable for their inability to learn from repeated mistakes, others have also greatly underestimated the growth of solar PV[iv].    Crucially, as a recent study in Nature Energy[v] shows, this tendency extends to many energy models used in policy making, including those relied on by the IPCC in its Assessment Reports.

This is largely because models have underestimated both the effect of policy support on deployment and the rate of technological progress, and so have underestimated the resulting falls in cost both in absolute terms and relative to other technologies.  Where new information has been available there has often been a lag in incorporating it in models.  Feedbacks between cost falls, deployment and policy may also have been under-represented in many models.  Consequently models have understated both growth rates and ultimate practical potential for solar PV.

This damages policy making  …

Does this matter?  I think it does, for at least two reasons.

First, if policy is based on misleading projections about the role of different technologies then policy support and effort will likely be misdirected.  For example, means of integrating solar PV at very large scale into energy systems look to have been under-researched and under-supported.  Other low carbon technologies such as power generation with CCS may have received more attention in comparison to their potential[vi].

Second, there is a risk of damaging the policy debate.  In particular there is a risk of exacerbating polarisation of the debate, rather than creating a healthy mix of competing judgements.  There is already a tendency for some commentaries on energy to favour fossil energy sources, and perhaps nuclear, and for others to favour renewables – what one might call “traditionalist” and “transitionalist” positions.  Traditionalists, including many energy companies, tend to point to the size and inertia of the energy system and the problems of replacing the current system with new sources of energy.  Transitionalists, including many entrepreneurs and environmentalists, tend to emphasise the urgent need to reduce emissions, the speed of change in technologies and costs now underway, and the exciting business opportunities created by change.

Both perspectives have merit, and the debate is too important to ignore either.  The IEA provides an example of distorting the debate. It will naturally, due to its history, tend to be seen as to some extent favouring the traditionalist viewpoint.  If this perception is reinforced by grossly unrealistic projections for renewables it risks devaluing the IEA’s other work even when it is more realistic, leaving it on one side of the debate. An opportunity for a balanced contribution from a major institution is lost.  The debate will be more polarised as a result, risking misleading policy makers, and distorting policy choices.

Securing balanced, well informed debate on the transition to a low carbon energy system is quite challenging enough.  Persistently underestimating the role of a major technology does not help.

Adam Whitmore -26^th September 2017

 

 

[i] http://www.bp.com/content/dam/bp/en/corporate/pdf/energy-economics/statistical-review-2017/bp-statistical-review-of-world-energy-2017-renewable-energy.pdf

[ii] For details see here, here and  here

[iii]  https://steinbuch.wordpress.com/2017/06/12/photovoltaic-growth-reality-versus-projections-of-the-international-energy-agency/

[iv] An exception, as I have previously noted is work by Greenpeace.  Some previous scenario work by Shell was also close on wind and solar, but greatly overestimated the role of CCS and biofuels.

[v] The Underestimated Potential for Solar PV Energy to Mitigate Climate Change, Creutzig et. a. Nature Energy, Published 28/08/17

[vi] CCS still looks essential for decarbonisation in some cases, and given lead times for its development continued research and early deployment is still very much needed.  This is especially so for industrial applications.  Deployment in power generation looks likely to be more limited over the next decade or more, though some may still be needed when to move to very low emissions, and eventually to zero net emissions.  However the contribution of CCS to power generation now looks likely to be much less than that from solar PV.

Deploying CCS on fossil fuel plant is more of a priority than implementing negative emissions technologies

The potential for biomass with CCS and direct air capture of CO₂ should not distract from deployment of CCS on fossil fuel plants over the next few decades.  Among other things, learning from CCS on fossil fuels will help make eventual deployment of CCS on biomass cheaper and more effective.

There appears to be increasing likelihood that atmospheric concentrations of greenhouse gases will grow to exceed levels consistent with the target specified in the recent UNFCCC Paris agreement of limiting temperature rises to “well below” two degrees.  Such an outcome would require CO₂ to be removed from the atmosphere faster than natural sinks allow, in order to restore concentrations to safe levels.  Near zero net emissions in the latter part of this century will also be needed to stabilise concentrations.

Many models of future emissions pathways now show negative emissions technologies (technologies that result in a net decrease in CO₂ in the atmosphere) needing to play a major role for in meeting climate goals. They have the potential to remove carbon dioxide from the atmosphere in the event of “overshoot” of target atmospheric concentrations, and to balance remaining emissions from sectors where abatement is difficult with a view to achieving net total emissions of close to zero.  But the application of such technologies should not be considered in isolation.

Bio Energy with CCS (BECCS)

Bio energy with CCS (BECCS ) is the most widely discussed approach to negative emissions.  BECCS is not a single technology but a combination of two major types of CO₂ removal.  Bioenergy from burning biomass to generate electricity or heat emits a substantial amount of CO₂  on combustion – around as much as a coal plant.  However much of this can be captured using CCS.  More carbon dioxide is reabsorbed over time by the regrowth of the plants, trees – or perhaps algae – that have been harvested to produce the bioenergy.  Together, the capture of the CO₂ from the flue gas and the subsequent absorption of CO₂ from the atmosphere by regrowth of biomass can lead to net removal of CO₂ from the atmosphere, although this takes time.  (The net amount of CO₂, that is emitted on a lifecycle basis from burning biomass without CCS depends on the type of biomass and is subject to considerable variation and uncertainty – a controversial topic that would need another post to review.)

However at an energy system level, where the CO₂ is captured – biomass plant or fossil fuel plant – is less relevant than the total amount that’s captured.  Broadly speaking, if there is a biomass plant and fossil fuel plant both running unabated the same benefit can be achieved by capturing a tonne of CO₂ from either.

Indeed there may be advantages to putting CCS on a conventional plant rather than biomass plant.  It may be technically more tractable.  Furthermore, CCS require a lot of energy to capture the CO₂ and then to compress and pump it for permanent storage.  Biomass is likely to be supply constrained (again, this is an issue that requires a post in itself), so using biomass rather than fossil fuels to provide this energy may limit other applications.  Only when there are no fossil fuel plants from which to capture CO₂ does biomass plant become unambiguously a priority for CCS.  This is clearly some way off.

Furthermore biomass with CCS for electricity generation may not be the best use of bioenergy.  Converting sunlight to bioenergy then turning that into electricity is a very inefficient process.  Typically only 1-2% of the sunlight falling on an area of cropland ends up as useful chemical energy in the form of biofuels.  There are various reasons for this, not least of which is that photosynthesis is a highly inefficient process.  Burning biomass to make electricity adds a further layer of inefficiency, with only perhaps a third or less of the energy in the biomass turned into electricity.  Sunlight therefore gets converted to electricity with an efficiency of perhaps 0.5%.  This compares with around 15- 20% for solar cells, implying that scarce land is often likely to be best used for solar PV.  (The calculation is closer if solar PV is used to create storable energy e.g. in the form of hydrogen).   For similar reasons the use of biofuels rather than electricity in transport is inefficient, in part because internal combustion engines are less efficient than electric motors.

Limited available biomass may be better used for those applications where it is the only available lower carbon energy source, notably in aviation and (likely) heavy trucks, or for other applications such as district heating with CCS, where the ability to store energy seasonally is especially valuable.

At the very least, detailed system modelling will be required to determine the optimal use of biomass.  Suggesting that BECCS should have a major role to play simply because in isolation it has negative emissions may lead to suboptimal choices.

Direct Air Capture (DAC)

Direct Air Capture (DAC), where carbon dioxide is chemically absorbed from the atmosphere and permanently sequestered, can also reduce the stock of CO₂ in the atmosphere.  However the typical concentration of CO₂ in a flue gas of a power plant or industrial plant is several percent, about a hundred times as great as the concentration of 0.04% (400 ppm) found in the atmosphere.  This makes the capture much easier.  Furthermore, millions of tonnes can be captured and piped from a single compact site using CCS, generating economies of scale on transport and storage.  In contrast DAC technology tends to be more diffuse.  These considerations imply that CCS from power plants and industrial facilities is always likely to be preferable to direct air capture until almost all the opportunities for CCS have been implemented, which again is a very long way off.

Uncertainties and optionality

There are many uncertainties around negative emissions technologies, including the availability of biomass, cost, and the feasibility of reducing emissions in other sectors.  For these reasons developing optionality remains valuable, and research to continue to develop these options, including early trial deployment, is needed, as others have argued[i].

One of the best ways of developing optionality is to deploy CCS at scale on fossil fuel plants.  This will reduce the costs and enable the development of improved technologies through learning on projects.  It will also help build infrastructure which can in turn benefit  BECCS.  This needs to run in parallel with ensuring that the lifecycle emissions from the bioenergy production chain are reduced and biodiversity is safeguarded.

Negative emissions technologies may well have a role to play in the latter part of the century.  But they seem likely to make more sense when the economy is already largely decarbonised.  In the meantime deployment of CCS, whether on industrial facilities or power plants, needs to be a much greater priority.

Adam Whitmore – 21^st March 2016

[i] Investing in negative emissions, Guy Lomax,  Timothy M. Lenton,  Adepeju Adeosun and Mark Workman, Nature Climate Change 5, 498–500 (2015)  http://www.nature.com/nclimate/journal/v5/n6/full/nclimate2627.html?WT.ec_id=NCLIMATE-201506

 

 

CCS is making progress – but not much in power generation

There is now sufficient experience of CCS around the world to begin to see what makes early projects happen.  Most projects capture from natural gas processing or other industrial processes, with little progress in the power sector.

Many projections show CCS as a major future contributor to decarbonisation.  But, as described in my last post, energy technologies take a long time to reach scale, and CCS has to date developed less rapidly than many were hoping a few years ago.  However with around eighteen large-scale projects now either operational or under construction patterns have begun to emerge that indicate which factors make for a successful project [i].

Use of captured CO₂ for Enhanced Oil Recovery (EOR) is common across projects of various types, being a feature of two thirds of projects.  When injected into oil reservoirs each tonne of CO₂ can enable the production of (typically) two or three additional barrels of oil, making the CO₂ a valuable commodity rather than a waste product.  While the carbon capture project is unlikely to be able to capture all of this value (much of it flowing to the owner of the oil field), the revenue can be substantial.  For example, the price paid for CO₂ in some Canadian projects is understood to be $60/tonne or more.  This greatly enhances the economics of a project relative to incurring a cost for transport and storage, which in the absence of oil revenue is likely to be at least $20/tonne.

The most widespread application of CCS technology to date, with eight projects out of the eighteen and over 60% of annual volume captured, has been for natural gas processing, where CO₂ needs to be removed to meet the specifications required by the pipeline network.  There is a wide range of projects, including onshore processing where the CO₂ is used for EOR, such as at the Val Verde project in the USA, offshore processing where CO₂ is injected into saline formations, for example the Sleipner and Snohvit projects in the Norwegian North Sea, and the Gorgon project under construction in Australia, where CO₂ will be captured from a LNG liquefaction facility.

There are other projects where a relatively pure stream of CO₂ is produced as part of an industrial process, avoiding much of the capture costs associated with dilute CO₂ streams.  These include capture from electric arc furnaces at steel mills, such as at the ESI project in Abu Dhabi, and capture from steam methane reformers (SMRs), such as an Air Products plant that has just begun operating in Texas.  Other industrial projects include Shell’s Quest oil upgrader in Alberta and the Enid fertiliser plant in Oklahoma.  With substantial natural gas processing facilities, industrial facilities and onshore oil fields suitable for EOR, North America has been the main location for all types of CCS projects to date, around two thirds being in Canada or the USA.

However the contribution of CCS to decarbonising the power sector and other combustion remains minimal.  There are only two full-scale (greater than 100MW capacity) power projects under construction. The largest of these, the Kemper County project in Mississippi, has relatively high emissions (estimated to be greater than those of a CCGT per MWh) due to its use of lignite and a relatively low capture rate.  The other is the Boundary Dam project in Saskatchewan where construction is nearing completion and commissioning is due to start later this year.

CCS projects are dominated by natural gas processing and industry with relatively little capture from the power sector …

Source:  Global CCS Institute

Whichever of the CCS technologies a power project uses – pre-combustion, post-combustion or oxyfuel – a chemicals plant needs to be added to the power plant, and this is inevitably expensive.  The large additional capital and operating expenditures required for a capture system, combined with the loss of efficiency due to the energy required to run the capture process, including the electricity required to compress the CO₂ ready for transport, add greatly to the cost of power.  According to a recent study sponsored by the UK government, power generation with CCS has a cost of around £161/MWh at present, about three times the cost of power from conventional fossil fuels [ii].  The study suggests that this could potentially be reduced to around £100/MWh by the early 2020s, although this may prove a somewhat optimistic estimate.  Meanwhile, the Kemper County plant is reportedly suffering cost over-runs.

The large additional cost of power from CCS means that it needs types and levels of enabling support similar to other early stage power generation technologies. The power sector projects that are under construction both have favourable financial arrangements.  The Boundary Dam project is being developed by the province-owned utility, Saskpower. This means that the additional costs of CCS can be covered through government-backed financing and through the ability to pass on costs to electricity users.  The Kemper County project is allowed to recover its costs from the local rate base from the start of construction, greatly improving the financial attractiveness of the project.  Both projects also benefit from sales of CO₂ for EOR.

Financial support is likely to take the form of some combination of a premium price for the power, capital grants, loan guarantees and other source of low cost capital, and perhaps support for provision of common infrastructure, including pipelines and sinks.  A substantial per MW or per MWh contribution is needed, and the relatively large scale of CCS projects means that finance needs to come in large blocks, with large amounts of support for each project.  Building projects will be necessary to enable “learning by doing” to bring the cost down substantially, but learning times are long due to long design and construction periods.

So far putting the necessary support in place has proved daunting for most governments, and public opposition has also hampered progress in some jurisdictions.  Europe has made little progress, and in the USA the potential to reduce emissions much more cheaply by switching from gas to coal seems likely to lead to limited prospects for CCS power projects in the short to medium term.  However there is increasing interest in CCS in China, and it is possible that, as with so much else, development in China will prove crucial to the global picture over time.  The strength of interest in CCS may in turn depend on progress with developing shale gas in China.

Achieving scale sufficient to capture a large proportion of the world’s combustion emissions from the power sector or elsewhere will in any case be an enormous task.  CO₂ is 27% carbon.  Fossil fuels are more typically 75-80% carbon [iii] by mass.  From this, a simple mass balance implies that the capture, transport and storage to dispose of the CO₂ must handle about three times the mass of the production and transport of the fossil fuels burnt.

Many new CCS projects are likely to continue to be outside the power sector, especially where there is potential for EOR, and this will make important contributions, for example to knowledge of reservoir management and in some cases to the scale of pipeline networks.  It remains important that some power sector projects are undertaken at scale, as implementing widespread CCS on power plants, especially on gas, remains an option that will probably need to be exercised in the coming decades.  However realising power projects with CCS will continue to be a difficult and, very likely, slow process.

Adam Whitmore  3^rd June 2013

Thanks to Dave Mirkin of 2CO for providing valuable input for this post.

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[i] See the 2012 Annual Report from the GCCSI and January update.

http://www.globalccsinstitute.com/publications/global-status-ccs-2012

http://cdn.globalccsinstitute.com/sites/default/files/publications/85741/global-status-ccs-january-2013-update.pdf I have added the Abu Dhabi ESI project to the total as I understand it has now progressed to the construction phase.  A similar project is understood to be planned in Saudi Arabia, but is excluded due to lack of firm information.

[ii] https://www.gov.uk/government/publications/ccs-cost-reduction-task-force-final-report

[iii] This is a typical number.  Natural gas has a carbon content about this level.  The carbon content of oil is higher, coal varies depending on quality.  The essential point that the waste disposal must handle much greater mass than the fuel supply remains unaffected.