With energy demand predicted to double over the next two decades and fossil fuels set to supply more than half of the world’s energy needs through to 2030, carbon capture and storage (CCS) is seen as a major contributor to reducing man-made carbon-dioxide emissions.
The UK is making massive commitments in that direction, with CCS expected to play a fundamental role in combating climate change. It will, if successful of course, help Kyoto Protocol signatories meet their legally binding greenhouse-gas reduction targets.
But while early implementation of capture technologies such as planned for ScottishPower’s Longannet power station could help reduce global CO emissions by 26% by 2050, there is currently no way of measuring that accurately.
That omission could cost governments worldwide a huge amount in lost green tax revenues. The British Treasury alone could miss out on billions of pounds of revenues.
It could have a huge impact on the success or otherwise of emissions trading schemes such as the UK’s, and companies and other organisations involved in carbon capture could be equally out of pocket over time.
The TUV NEL laboratory at East Kilbride warns: “In terms of CO trading under the EU Emissions Trading Scheme, it is anticipated that there will be a large risk of financial exposure to stakeholders in the scheme unless the potential measurement systems are further investigated and developed to ensure measurement uncertainty throughout the various stages is reduced and verified.”
TUV NEL says that it is essential for all captured CO be accurately measured across each stage of the CCS chain.
“This is necessary for environmental purposes to detect CO leakage, and for verification of the CO quantity accounted under offsetting within emissions trading schemes,” says TUV NEL in a study released exclusively to Energy.
“To put the importance of accurate flow measurement into perspective, consider the UK’s largest emitting power station. This emits approximately 22million tonnes of CO per annum; every 1% uncertainty in flow measurement could result in a £6.6million financial exposure in the trading scheme based on a carbon trading price of £30 per tonne, as projected between 2013 and 2015.”
TUV NEL warns that most carbon-capture research has so far focused primarily on the techniques involved in the capture and separation processes and in the geological surveying and monitoring of storage sites.
And yet, despite a “vast number” of flow measurement issues and challenges arising from the unique behaviour of CO, as yet there has been no significant research undertaken in this area.
“This is vital, particularly where CO properties can change significantly through the chain and in the presence of other compounds,” says the laboratory.
“The majority of flow metering technologies are likely to have limitations when used in CCS schemes and none are expected to meet the UK’s proposed 2% measurement uncertainty limit unless single-phase, steady, predictable and controllable flow conditions are attainable at the location of measurement.
“Whichever flow measurement techniques are used, traceable calibration of the individual flow meters will still be required.
“At present, there are no facilities capable of providing calibrations under conditions representative of those that will be encountered in CCS schemes.
TUV NEL says there is a general assumption that existing flow meters can be used, but this could lead to problems unless they are addressed.
This, in turn, could lead to potential problems with industry meeting the proposed requirements set down in the UK Government’s EU Emissions Trading Scheme (ETS) draft CCS monitoring and reporting guidelines.
And, of course, the regulatory bodies, too, will not be in a position to support the regulatory requirements.
As a result, TUV NEL wants to see full investigation of the limitations and capabilities of various flow metering technologies and practices to progress CCS measurement and ensure adequate systems are in place to support the arrival of the CCS regulatory framework.
