Tag Archives: 2050 targets

Hydrogen and electricity for low carbon heat

Hydrogen and electricity are competing carriers, and there may be a role for both in providing low carbon heat.

There has recently been a lot of interest in the role of hydrogen as a carrier of low carbon energy, because it produces no CO2 on combustion (or oxidation in a fuel cell).  This is the first of three posts looking at hydrogen and how it might compete with electricity to provide low carbon heat.  Hydrogen and electricity may also compete in transport, but that is a large subject in its own right and will need to await further posts.

This first post outlines some of the possibilities and the issues raised.  The next post will compare electricity with hydrogen for heating in buildings.  The third post will look at the ways they may complement each other to supply heat.

There are broadly two main sources of primary energy for low carbon heat:

  • Fossil fuels with CCS, which I’ve assumed in these posts will usually be natural gas.
  • Renewables, likely in practice to be mainly wind and solar.

Each of these primary energy sources can get to the energy consumer in the form of electricity or hydrogen.  Wind and solar can produce low carbon electricity directly, or they can produce hydrogen via electrolysis of water.  Natural gas can be burnt in a CCGT to produce electricity.  It can also be processed to produce hydrogen, most commonly in a steam methane reformer (SMR).  I’ve assumed here that SMRs are used, although many are looking at alternative approaches such as autothermal reforming (ATRs) which may allow for higher efficiencies and capture rates.

If fossil fuels are used CCS is required, as both CCGTs and SMRs produce CO2.  This means they provide low carbon energy, rather than a zero-carbon energy, as a maximum of 90-95% of the CO2 produced is captured.  Any CCS built now or in the future will likely still be in use by 2050, so its capture rate must be judged against 2050 net-zero targets.  In this context, the residual emissions from any large-scale use of CCS for fossil fuels are likely to be significant, and may place limits on the extent of deployment.  SMRs produce different streams of CO2. Some of this is concentrated and so relatively easy to capture, some is more dilute.  Both streams need to be captured for the technology to play an appropriate role in a net-zero carbon economy.

Both CCGTs and SMRs also produce waste heat, which may be used, so improving the overall thermal efficiency, although applications to date have been limited.

Hydrogen can be converted into electricity using a fuel cell or CCGT (with appropriately designed turbines).  This may enable use of hydrogen for electricity storage.

Electricity for building heating is likely to come from heat pumps (likely mainly air source heat pumps) as these greatly improve efficiency.

This gives a variety of routes for primary energy to low carbon end use. These are shown in the diagram below.  In practice several of these may co-exist, and some may not happen at scale.  The pathways shown assume natural gas cannot continue to act as a carrier of energy to individual buildings.  This is because its combustion inevitably produces CO2 and very small-scale CCS for individual buildings is likely to prove impractical, for example because of the very extensive CO2 transport network that would be required.

Both fossil fuels and renewables can deliver energy as electricity or hydrogen …

Which mix of these pathways will provide the best solution? It’s not yet clear.  It will depend on various factors.

Suitability for end use.  Some industrial processes require high temperature heat or a direct flame, which heat pumps cannot provide.  Conversely, hydrogen needs to demonstrate its safety in a domestic context, though this is likely tractable.

Consumer acceptability. This is critical for residential heating, and both hydrogen and heat pumps face potential difficulties.  For example, heat pumps may be perceived as noisy, or require modifications such as installation of larger radiators which people resist.

Costs.  Which route is cheaper depends on a wide range of factors, including :

  • The capital costs of the equipment (e.g. CCGT or SMR, hydrogen boilers, and heat pumps)
  • The costs of reinforcing, creating or repurposing grids, including the extent to which the natural gas gird can be repurposed for hydrogen, and the cost of reinforcing the electricity distribution network to accommodate demand from heat pumps.
  • The cost of the primary energy, for example whether renewable energy is produced at times of low demand so might be available at a low price. If electricity from renewables is available very cheaply then resistance heating without heat pumps may make sense in some cases.
  • The thermal efficiency of the processes, for example the extent to which CCS adds costs by requiring additional energy, and the coefficient of performance (heat out divided by electricity in) for heat pump, especially in winter.
  • The costs of electricity storage via batteries or as hydrogen.
  • Load factor for heat and electricity production.

Many of these variables are uncertain.  They also vary with location and over time. The very large cost falls for renewable electricity demonstrate the need for caution in judging options on present costs.

In my next post I will take a look at how these factors may play out for building heating in the UK, and will consider the policy implications.

Adam Whitmore – 30th September 2019

 

 

Europe’s phase out of coal

Europe is progressing with phasing out hard coal and lignite in power generation, but needs to move further faster, especially in Germany and Poland

Reducing coal use in power generation and replacing it with renewables (and in the short run with natural gas) remains one of the best ways of reducing emissions simply, cheaply and quickly at large scale.  Indeed, it is essential to meet the targets of the Paris Agreement that the world’s limited remaining cumulative emissions budget is not squandered on burning coal and lignite in power generation.

Europe is now making progress in phasing out coal.  The UK experience has already illustrated what can be done with incentives from carbon pricing to reduce coal generation.  Emissions from coal have reduced by more than 80% in the last few years, even though coal plant remains on the system[i].  However, many countries, including the UK, are now going further and committing to end coal use in power generation completely in the next few years.  The map below shows these commitments as they now stand.  Most countries in western Europe now have commitments in place. (Spain is an exception.  The government is expecting coal plant to be phased out by 2030, but currently does not mandate this.)

Map: Current coal phase-out commitments in Europe[ii]

Source: Adapted from material by Sandbag (see endnotes).

In some countries there is little or no coal generation anyway.  In other countries plants are old and coming to the end of their life on commercial grounds, or are unable to comply with limits on other pollutants.  In each case phase-out is expected to go smoothly.

However, the largest emitters are mainly in Germany and Poland and here progress is more limited.  Germany has now committed to coal phase-out.  But full phase-out might be as late as 2038.  Taking another 20 years or so to phase out such a major source of emissions is simply too long.  And Poland currently looks unlikely to make any commitment to complete phase out.

This means the Europe is still doing less than it could and should be doing to reduce emissions from coal and lignite.  As a result, EU emissions are too high, and the EU loses moral authority when urging other nations, especially in Asia and the USA, to reduce their emissions further, including by cutting coal use.

Several things are needed to improve this situation, including the following.

  • Further strengthening the carbon price under the EUETS by reducing the cap. I looked at the problem of continuing surpluses of allowances in another recent post, and accelerated coal closure would make the surplus even greater.  Although the rise in the EUA price in the last 18 months or so is welcome, further strengthening of the EUETS is necessary to reduce the risk of future price falls, and preferably to keep prices on a rising track so they more effectively signal the need for decarbonisation.
  • Continuing tightening of regulations on other pollutants, which can improve public health, while increasing polluters’ costs and therefore adding to commercial pressure to close plant.
  • Strengthening existing phase out commitments, including be specifying an earlier completion date in Germany.
  • Further enabling renewables, for example by continuing to improve grid integration, so that it is clear that continuing coal generation is unnecessary.

As I noted in my last post, making deep emissions cuts to avoid overshooting the world’s limited remaining carbon budget will require many difficulties to be overcome.  There is no excuse for failing to make the relatively cheap and easy reductions now.   Reducing hard coal and lignite use in power generation in Europe (and elsewhere) continues to require further attention.

Adam Whitmore – 18th June 2019

[i] See https://onclimatechangepolicydotorg.wordpress.com/2018/01/17/emissions-reductions-due-to-carbon-pricing-can-be-big-quick-and-cheap/

With and updated chart at:

https://onclimatechangepolicydotorg.wordpress.com/carbon-pricing/price-floors-and-ceilings/

[ii] Map adapted from Sandbag:

https://sandbag.org.uk/wp-content/uploads/2018/11/Last-Gasp-2018-slim-version.pdf

and data in:

https://beyond-coal.eu/wp-content/uploads/2018/11/Overview-of-national-coal-phase-out-announcements-Europe-Beyond-Coal-November-2018.pdf

and https://www.eia.gov/todayinenergy/detail.php?id=39652

New long term targets for emissions reduction are needed.

The UK and other jurisdictions need to set target dates for reaching net zero greenhouse gas emissions.  These need to be reinforced by new targets for 2060 that are at least close to zero, and by reaffirmed or strengthened targets for 2050.

Ten years ago setting emissions reduction targets for 2050 was a major step forward

2018 sees the tenth anniversary of the UK’s Climate Change Act[i].  This remarkable piece of legislation established a legally binding obligation for the UK to reduce its greenhouse gas emissions by 80% from 1990 levels by 2050, with obligations along the way in the form of five year carbon budgets.  So far progress has been remarkably good, though significant challenges remain.

Other jurisdictions also adopted 2050 targets at around the same time.  In 2005 California also set a target of an 80% reduction from 1990 levels[ii].  In October 2009 the EU established a long term EU goal for reducing emissions by 80-95% from 1990 levels by 2050[iii].

At the time these targets were path breaking.  However, ten years on there are good reasons for reviewing and extending them.

But now the world has moved on …

  • When the targets were established, the period to 2050 seemed long enough to give appropriate strategic guidance to policy makers and investors. However, future dates are now ten years closer.  A 2060 target now gives about the same time horizon for planning as the 2050 targets did when they were established.
  • The Paris Agreement sets targets to limit temperature rises which imply stringent limits on cumulative emissions. It also sets a goal of net zero global emissions in the second half of the century.
  • A fifth or more of the world’s carbon budget that remained in 2008 has since been used up[iv], increasing the urgency of emissions reductions.

Extending targets to reflect these changes would have some clear benefits … 

Together these changes imply a strong case for setting new targets now.

The most compelling target would be a date by which emissions must fall to net zero.  Such a target would make it clear to all sectors that they need to completely decarbonise by a specified date.  At the moment emissions of up to 20% of 1990 levels are allowed even in 2050.  This allows each of those sectors where decarbonisation is more difficult – for example parts of industry, agriculture or residential heating – to largely continue in a belief that there will still be plenty of room for them within the 2050 emissions limit, even though this cannot be true for most sectors.  This in turn allows them to continue to believe they can carry on indefinitely without taking the steps needed to decarbonise.  A date for reaching zero makes it clear this can’t happen.

Setting stringent target for 2060 – at or close to zero – would also give investors in low carbon infrastructure greater confidence, and deter investment in higher carbon alternatives. In the case of the UK and California, a simple extrapolation of their current targets would suggest a 2060 target of a 93% reduction from 1990 by 2050, reaching zero by 2065.

As part of the process of setting these longer term goals the existing 2050 targets need to be at least reaffirmed and preferably tightened.  If this is not done there is the risk that policy makers will simply see the problem as having become more distant, and delay action.  This is the last thing that the climate needs.

2050 targets may also need to be revised …

As a first step, the EU’s target of 80-95% cuts clearly needs to be made more precise.  The current uncertainty of a factor of four in the level of emissions allowed in 2050 is too wide for sensible policy planning.

However the events of the last ten years also raise the question of whether the stringency of the 2050 targets need to be increased, with implications for later periods.  The UK Government’s former Chief Scientific Adviser Sir David King and others have suggested that there is a strong case for the UK seeking to reach net zero emissions by 2050[v].  The difference in cumulative emissions in declining linearly to net zero by 2050 instead of by 2065 is substantial, at a little over 3 billion tonnes – equivalent to about 8 years of current UK emissions.

The goal of reaching zero emissions by 2050 is clearly desirable in many ways.  However there is a risk that it may have unwanted side effects.  The government’s advisory body, the Committee on Climate Change has pointed out that policies are not in yet place even to meet current goals for the fifth carbon budget in around 2030[1].  The route to net zero emissions in 2050 – just over 30 years from now – looks even less clear.  Indeed reaching that goal even by 2065 remains challenging.  If even tighter targets are introduced they may come to be regarded as unrealistic, which may in turn risk weakening commitment to them.  A somewhat slower emissions reduction track may prove a relatively acceptable price to pay for retaining the credibility and integrity of the targets.

Whatever the judgement on this, the need for longer term targets is clear.  Governments need to set dates for reaching net zero emissions.  These need to be supported by targets for 2060 that specify continued rapid reductions in emissions after 2050, and by reaffirmation of 2050 targets, tightening them as necessary.  These new targets will in turn help stimulate the additional actions to rapidly reduce emissions that are ever more urgently needed.

Adam Whitmore – 6th November 2017

 Notes:

[1] https://www.theccc.org.uk/publication/2017-report-to-parliament-meeting-carbon-budgets-closing-the-policy-gap/

[i] https://www.theccc.org.uk/tackling-climate-change/the-legal-landscape/the-climate-change-act/

[ii] https://www.arb.ca.gov/cc/cc.htm

[iii] https://www.consilium.europa.eu/uedocs/complementary measures_data/docs/pressdata/en/ec/110889.pdf

[iv] The calculation is based on data in the IPCC Fifth Assessment Report, Synthesis Report.  This quotes a  cumulative budget of 3700 billion tonnes of CO2 for a two thirds probability of staying below 2 degrees.  Of this 1800 billion tonnes had been used by 2011.  Assuming CO2 emissions of roughly 40 billion tonnes p.a. including land use gives a remaining budget in 2008 of 1920 billion tonnes.  Over the subsequent ten years about 400 million tonnes CO2, which is just over a fifth of 1920 billion tonnes, have been emitted.

[v] http://www.independent.co.uk/environment/ministers-greenhouse-gas-emissions-fail-cut-environment-greg-clark-chief-scientist-david-king-a7969496.html