Carbon Capture and Storage (CCS) refers to an array of technologies designed to reduce emissions from industrial point sources such as power plants. CCS involves collecting CO2 before it enters the atmosphere, then permanently storing it deep underground geologic formations.
Scientists are exploring five options to permanently store Earth’s excess carbon dioxide emissions that are contributing to global warming. All involve transporting it either to saline aquifers or depleted oil and gas reservoirs for permanent isolation.
What is CCS?
Carbon Capture and Storage (CCS) technology enables industrial processes to release CO2 at its source rather than into the atmosphere, by isolating it from other gases and depositing it deep underground geological formations.
CCS technology can be found in coal or natural gas power plants and is an indispensable element for transitioning towards low-carbon energy sources if global warming is to remain below 1.5 or 2 degrees C. Furthermore, CCS forms part of technology needed to curb harmful emissions associated with cement production as well as steel making.
Carbon dioxide can also be injected for enhanced oil recovery or stored in geological formations, and transported by ship between CCS sites and ports at present. An amendment to IMO’s London Protocol, known as LCCS, awaits formal acceptance by two-thirds of Contracting Parties that will lead to its entry into force and enable safe offshore CO2 transport and storage.
How does CCS work?
CCS technologies are expected to play an essential part in meeting global climate targets, according to many prominent organizations such as the International Energy Agency, IRENA, and Bloomberg New Energy Finance. CCS technologies capture CO2 emissions from power plants and other industrial facilities before transporting it underground for storage in geological formations such as saline aquifers or depleted oil and gas fields.
Power plants equipped with CCS can reduce CO2 emissions to the atmosphere by as much as 90%, compared with power plants without CCS. Once captured, carbon dioxide is securely stored underground to keep it out of our atmosphere and oceans.
CCS can also be employed to reduce difficult-to-control industrial emissions from cement and steel factories, with direct air capture (DAC) technology helping directly remove carbon from the atmosphere – also known as negative emissions technology (NET). Deployment can be supported through regulatory frameworks with incentives or funding mechanisms for expeditious approval processes that support its deployment.
What are the benefits of CCS?
Research by both IPCC and IEA indicates that carbon capture storage (CCS) can be an essential tool in helping achieve net-zero emissions, particularly for sectors such as power generation, industrial processes and transportation that are difficult to decarbonize without significant investments. CCS may also increase energy security by improving domestic coal supplies reliability.
Once captured, CO2 can be transported and stored underground using deep geological formations similar to those that have held oil and gas reserves for millions of years. Unfortunately, however, critics of this technology point out its potential contribution to marine pollution if left unregulated.
Environmental advocates often see carbon capture and storage (CCUS) as an attempt to sustain polluting fossil fuel plants rather than shifting towards renewables or low-carbon production methods like wind or solar power production. Carbon capture in oil refineries, for instance, may reduce emissions related to producing petroleum-based fuels used by heavy industry and power generation; but doing so does not reduce overall emissions when these fuels are burned for power.
What are the challenges of CCS?
Carbon capture and storage remain on an uncertain path to becoming a key climate solution, despite increased investments, breakthrough technologies under development, international cooperation and strong support from governments around the world. It remains uncertain due to high costs, regulatory hurdles and inadequate policy incentives.
Integrating CCS into power plants, steel mills and other industrial facilities presents technical difficulties that can drive up project costs. Connecting capture sites to geologic CO2 storage locations requires extensive pipeline infrastructure that is both expensive and complex to construct. Furthermore, risks associated with transporting and storing CO2 over geological timescales require thorough site assessments, risk mitigation procedures and ongoing stewardship responsibilities for managing the storage site(s).
Even when projects possessing appropriate technology have the ability to capture carbon emissions, strong regulatory support must be secured to make CCS competitive with fossil fuels and create economic signals necessary for making its deployment cost-effective over time. Furthermore, legal frameworks that outline responsibility for leakage or unexpected environmental impacts is imperative.