The world faces an apparently intractable problem. It must generate more electricity to satisfy the insatiable appetite of the global economy while taking action to reduce carbon emissions. Could carbon capture and storage provide a solution?

Mike Farley, Doosan Babcock Energy Ltd, UK

Dr Mike Farley, Doosan’s Director of Technology Policy
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Demand for electricity is continuing to rise throughout the world, and finding ways to meet this demand and cut emissions at the same time will be a major challenge. In the long term, renewable energy sources such as wind, tidal and geothermal heat, will help to generate electricity with reduced emissions. However, renewables alone cannot fill the impending energy gap. A balanced portfolio of clean coal, gas, nuclear as well as renewables, is the only solution to preventing this gap, reducing emissions and ensuring security of supply.

To meet future energy demand, coal needs to be part of the power generation mix. Governments and industry have to demonstrate a commitment to clean coal technologies and strive to make power generation from coal as clean as possible. It is predicted that in the EU alone CO2 reductions from using carbon capture and storage (CCS) in the power sector could reach 161 Mt by 2030 and 800 to 850 Mt (20 per cent) by 2050. New coal stations are 20 per cent cleaner than existing coal fired plants and will be 80 to 90 per cent cleaner once carbon capture and storage is added.

Sceptics argue that while clean coal may help reduce emissions it is not economically feasible. This might be true for now, but it is anticipated that the additional cost of CCS-equipped coal fired power stations will decrease considerably once the technology is ready to be launched on a commercial scale. To cut costs for transportation and avoid additional emissions, the latest EU directive on the geological storage of CO2 demands that existing laws should be amended to require that all combustion plants from now on have suitable space for the capture of CO2 at the installation site.

Contrary to popular belief, the storage of CO2 is not a new concept. The process is proven, and already millions of tons of CO2 have been successfully stored underground. All parts of the CCS process, from capture to transport and storage, have been in use for decades in other industries. In addition, the latest studies have demonstrated that electricity from CCS-equipped power stations will be less expensive than power generated from renewable sources.

Time for action

The International Energy Agency (IEA) Energy Technology Perspectives ‘blue scenario’, which is consistent with the World Energy Outlook 450 ppm case, defines how CO2 emissions reductions might be shared over a range of measures. CCS has a vital role, accounting for 19 per cent of the emissions reduction from the baseline.

The blue scenario requires 10.4 Gt of CO2 to be captured and stored per year and 30 per cent of electricity to be generated from CCS power plant by 2050. In this scenario, 157 GW of coal fired capacity is retrofitted with CCS and 543 GW of new capacity with CCS is installed.

Some 817 GW of gas fired capacity is equipped with CCS. This translates into 35 coal fired (500 MW, 17 GW/yr) and 20 gas fired (500 MW, 10 GW/yr) power plants with CCS per year, with widespread deployment from 2020 – 55 projects per year.

This can be achieved using a twin-track approach: building modern high-efficiency capture-ready clean coal power plants and simultaneously demonstrating suitable carbon capture and storage technologies at full scale is the quickest and most valuable immediate contribution many nations can make towards cutting CO2 emissions from fossil fuels globally. As soon as is practical, all fossil fuel powered plants should be designed ‘capture ready’. A reasonable target date for this is 2012. Between 2010 and 2020, around 1000 such plants can be anticipated globally. The demonstrations would be in two tranches:

  • Initial large-scale carbon capture and storage demonstration projects – 12 in Europe, 20 globally – committed by 2010 and operational by 2015;
  • An additional 100 full-scale early stage deployment projects globally, building up from 20 per year to 40 per year, committed by 2015 (before initial demonstrations are running) and operational by 2020.

Such a programme would be sufficient to build confidence in the technology and construct the necessary capacity in the industry to allow commercialization from 2020, as a precursor to the delivery, as envisaged in the IEA 2008 Energy Perspectives blue scenario, of 55 coal and gas CCS power plants per year. The prime targets for the first few years of ‘commercialization’ will be the capture-ready power plants built prior to 2020.

Doosan Babcock Energy’s global R&D centre in Renfrew, UK, for power plant boilers and carbon capture technologies
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If we are to avoid the looming energy gap we must act now. New coal power plants will need to be ready to supply energy to the grid within six or seven years. That means that we need to start building them immediately. To maintain the current proportion of coal in the generation mix it will be necessary for 30 to 50 per cent of new plant to be built in the UK, for example, for operation by the end of 2015 to be coal fired power stations. To meet its CO2 reduction targets the UK’s new plant will have to be more efficient, cause less pollution and be fitted with CCS. The work of the government’s UK Coal Forum has demonstrated that fitting CCS to the new coal and gas fired power plants expected to be built by 2016 alone could reduce CO2emissions from the UK power sector by 42 per cent in 2025.

UK-based companies are already leading the way in CCS and capture-ready technology. Doosan Babcock provides advanced, super-critical capture-ready boilers for customers in Germany and the UK, that produce 23 per cent less CO2 compared with the average UK coal power plant. The company has established a global R&D centre in Renfrew for power plant boilers and carbon capture technologies. Doosan Babcock and its parent, Doosan Heavy, can provide all three CCS technologies – post-combustion, oxyfuel and pre-combustion – and will participate in large-scale demonstration projects. The company recently acquired an equity stake in HTC Purenergy, a leading post-combustion CCS technology provider, and has signed a licensing agreement to use the technology at a global level.

International outlook

At the beginning of the current decade, China accounted for 11 per cent of world primary energy demand. According to the IEA’s latest World Energy Outlook this will rise to almost 22 per cent by 2030.

In a high growth scenario, China’s share of global energy demand will reach one quarter. India’s share is expected to rise to 7 per cent by 2030. It is understood that much of the increase in demand in both countries will be met by coal fired stations.

Japan has announced plans to capture and store 100 Mt of CO2 by 2020. The Japanese government and industry will support the development and demonstration of domestic CO2 technologies, as they supported flue gas desulphurization and selective catalytic reduction technologies as a precursor to exporting them.

Government action

As soon as CCS technology in coal fired power stations is ready for day-to-day use, the speed of its deployment will largely depend on the cost of the technology, legislation and the carbon price. If the cost per tonne of CO2 captured and stored is lower than the carbon price, the operators of power plants will be quick to implement the new technology. The EU Emission Trading System will recognise CO2 captured and safely stored as not having been emitted.

Governments should take a strong position on the importance of coal alongside other sources, gas in particular, in their generation mix. Electricity generation capacity is ageing.

In the UK there is a need for up to 15 GW of replacement fossil power plant by 2015. New nuclear plant is not an option in this time frame, and renewable energy, while it will make a contribution, will not alone be able to meet new capacity needs.

Gas generation is the default option, but this undermines energy security by increasing the generating industry’s exposure to imported gas price volatility. Gas generation is less environmentally sound than using indigenous gas, as approximately 25 per cent of the available energy is used to liquefy and transport the gas as liquefied natural gas.

It is important to note that coal power projects with CCS can provide cost-effective, low-carbon electricity compared with renewable generation, while the level of support required to get coal power plants with CCS built is less than that granted to offshore wind. Supporting an introductory tranche of coal CCS projects would give the government greater certainty of meeting its carbon reduction targets, while reducing the cost of energy for energy consumers and avoiding an over dependence on imported gas.

If we are to avert the impending energy gap, more ambition and urgency is needed from the government. To meet climate change targets, CCS technologies need to be promoted, developed and deployed quickly, and effectively commercialized by 2020. Governments need to provide sufficient incentives to drive three to four CCS projects covering the range of capture technologies and storage sites as soon as possible.

In the longer term, 2020 onwards, it is hoped that incentives will be provided by the carbon price under the Emissions Trading Scheme (ETS) or global equivalent, but, if not, CCS may need to be mandated. In the short and medium term, tranches will require incentives if the CO2 allowance price is not sufficient. The funding for such incentives could come from the ‘recycling’ of revenues raised by the auction of CO2 allowances for power plants. Full auctioning is envisaged from 2013.

Positive high-level endorsement of the future role of coal must be given, and a target for the proportion of coal in the portfolio and a time-scale for the achievement of near-zero emissions for coal generation must be set.