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Scottish Renewable Energy Zone (Designation of Area) (Scottish Ministers) Order 2005 -area of study
Executive summary
Carbon Capture and Storage ( CCS) is one of the critical technologies worldwide which will enable reduction of carbon dioxide (CO 2) emissions arising from large industrial sites. CCS allows the continued use of a diverse mix of energy sources, including fossil fuels, which improves the security of cost-effective electricity supply. Scotland has the opportunity and responsibility to reduce CO 2 emissions arising from burning of fossil fuels and their impact on climate change.
The EU plans to have 12 CCS plants operating by 2015. In February 2009, the UK Secretary of State for Energy and Climate Change stated an aspiration for the UK to have more than one demonstration project in operation enabled by government funding. However, these targets cannot be delivered without the underpinning knowledge from studies such as this.
Commitment to large-scale investment in CO 2 capture plant will require proven storage capability.
This study
- presents the first high-level screening of CO 2 storage sites available to Scotland
- evaluates the means by which CO 2 can be transported from power plants and other industrial activities to storage sites, and
- investigates the costs and business constraints.
This is the most comprehensive and fully integrated study performed in the UK, and was achieved by a collaborative partnership of Scottish Government, research universities and institutes, and a broad base of support from industry and business.
The conclusions show that Scotland has an extremely large CO 2 storage resource. This is overwhelmingly in offshore saline aquifers (deeply buried porous sandstones filled with salt water) together with a few specific depleted hydrocarbon fields. The resource can easily accommodate the industrial CO 2 emissions from Scotland for the next 200 years. There is very likely to be sufficient storage to allow import of CO 2 from NE England, this equating to over 25% of future UK large industry and power CO 2 output. Preliminary indications are that Scotland's offshore CO 2 storage capacity is very important on a European scale, comparable with that of offshore Norway, and greater than Netherlands, Denmark and Germany combined.
CO 2 storage in oil fields may be feasible in conjunction with CO 2-Enhanced Oil Recovery (CO 2- EOR). If offshore pipelines reliably delivering CO 2 could be developed through demonstration projects, then an increased number of oilfields could become economic for EOR providing other critical factors such as oil price, additional oil recovery and infrastructure suitability are also favourable. Additional benefits include delayed decommissioning costs and extended benefit to the economy through development of technology and expertise in offshore CO 2- EOR. However, contrary to many expectations, this study has shown that most oilfields in the northern North Sea cannot easily be used solely for CO 2 storage because sea water injection, commonly used to maintain field pressure during oil production, significantly reduces the amount of storage capacity for CO 2.
Pipelines are the best option for the secure and continuous transport of millions of tonnes of CO 2 from different CO 2 sources to collection hubs onshore and then to offshore storage hubs for local distribution to diverse storage sites. Several routing options exist and, importantly, can include the connection of pipelines carrying CO 2 originating from England or continental Europe. Capital and operational costs for CCS projects are similar to those of the hydrocarbon industry.
Electricity generated in Scotland from power plant fitted with CCS is shown by this study to be comparable in price to that generated from other low-carbon technologies. The cost of abatement per tonne of CO 2 is cheaper on coal plants than on gas, because coal produces larger amounts of CO 2 per unit of electricity. However, the cost per unit of low-carbon electricity from coal and gas CCS is approximately the same.
The key conclusions of the study are:
1. The amount of CO 2 produced from industrial sources within Scotland is about a tenth of that of the UK as a whole. Without CCS, Scotland is likely to produce between 300 and 700 million tonnes of CO 2 from 2010 to 2050 - that is, on average, between 8 and 18 million tonnes per year (Mt/year) depending on the proportions and types of power generation. In 2006, CO 2 output from major industrial sources in NE England amounted to over 50 Mt/year.
2. Geological reservoirs suitable for storage of CO 2 are classified according to whether they contain (or have contained) oil, gas, or saline water. Saline aquifers have the largest storage potential but with uncertainties regarding storage capacity of individual sites. From a resource of more than 80 saline aquifers studied, ten have been identified with a total potential CO 2 capacity in the range 4,600 to 46,000 million tonnes - a capability to store more than 200 years of Scotland's CO 2 output from its major fixed industrial sources.
3. Initial costs of assessing potential saline aquifer stores are likely to be considerably higher than for oil and gas fields which have previously been fully evaluated during many years of both exploration and production operations. Only detailed appraisal studies that include drilling of boreholes are likely to provide sufficient confidence to initiate a commercial-scale CCS project. Thus, pilot CO 2 capture projects will be an essential element of developing any new CO 2 storage site.
4. From a resource of more than 200 hydrocarbon fields, 29 have been identified as clearly having potential for CO 2 storage. Four gas condensate fields and one gas field offer significant potential for CO 2 storage. However, most of the oil fields can only be used as CO 2 stores in conjunction with CO 2- EOR technology.
5. CO 2- EOR may act as a stimulus for CCS especially if developers come to expect that the price of oil will remain over US$100 per barrel for the period of their investment. Development of a CCS infrastructure in Scotland could lead to application of CO 2- EOR (and, therefore, additional oil production and revenue) in certain fields.
6. Storage hubs are proposed to give multiple storage options within a geographical area to reduce costs and risks to CCS infrastructure. A pipeline network would be used to transport 20 million tonnes/year of CO 2 from sources to distribution hubs offshore. Capital costs are £0.7 to £1.67 billion, depending on hub location. The hubs are proposed to give multiple storage options within a geographical area to minimise costs and risks to CCS infrastructure. The preferred route is through an onshore pipeline from the Firth of Forth to St Fergus, then onwards to an offshore storage hub, while an offshore pipeline route from the Firth of Forth should also be considered. Transport of additional CO 2 from NE England is best served by a pipeline direct to an offshore storage hub. Ship transport is possible as an interim solution, ideally discharged at the offshore hub.
7. A phased approach is appropriate to support the development of CCS technology. Direct Government funding will be required in the short term for R&D and pilot projects. In the medium term, CCS demonstration projects required under the UK Government and EU programmes, will need income support. Other low-carbon technologies, such as renewable power generation, currently receive incentives which are envisaged to continue for the medium term. In the long term, low-carbon generation projects are capable of being supported by the price of carbon alone. However, the volatility of the carbon market will place an additional financial risk on such projects.
8. The long term carbon abatement cost of CCS coal and CCS gas appear comparable with other available low-carbon power generation technologies and CCS has the potential to materially contribute to carbon abatement in Scotland.
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