Science Centres: Energy

Bury it down a deep hole

Capturing carbon dioxide from large point-sources, such as power stations, and storing it in carefully selected deep geological reservoirs may form a significant part of a portfolio of future greenhouse gas mitigation measures. Here we highlight some findings of the recent Special Report on Carbon Dioxide Capture and Storage from the Intergovernmental Panel on Climate Change.

Potential emissions reduction

A power plant with carbon dioxide capture and storage (CCS) could reduce CO₂ emissions by as much as 80-90% overall compared to a plant without CCS.

Geological storage appears feasible

The technology for storing CO₂ in depleted oil and gas reservoirs, and in 'deep saline formations' (underground porous reservoir rocks saturated with brackish water or brine) has already proven economically feasible under specific conditions: 99% or more of the CO₂ injected into carefully selected deep geological formations is likely to be retained for 1000 years. The local health, safety, and environmental risks would be comparable to those from activities such as geological natural gas storage provided there is appropriate site selection, monitoring, regulation, and remediation.

Ocean storage is less well understood

The report discusses two approaches: injecting or dissolving CO₂ into the ocean; and forming 'lakes' of liquid CO₂ on the seafloor. Estimates of the proportion of CO₂ retained in ocean storage are lower than for geological storage. The methods could kill ocean organisms, and chronic effects on ecosystems over large ocean areas and long timeframes have not yet been studied.

What’s the cost?

Applying CCS to electricity production could increase electricity costs by about 1-5 US cents per kilowatt hour, assuming 2002 conditions and US dollar values.

More information

Full report (subject to final copy edit): www.ipcc.ch/ipccreports/special-reports.htm

Summary for policymakers: http://www.ipcc.ch/pdf/special-reports/srccs/srccs_summaryforpolicymakers.pdf