CCS is a broad term that encompasses a number of technologies that can be used to capture carbon dioxide from point sources, such as power plants and other industrial facilities; compress it; transport it mainly by pipeline to suitable locations; and inject it into deep subsurface geological formations for indefinite isolation from the atmosphere.This technology is a critical option in the portfolio of solutions available to combat climate change, because it allows for significant reductions in CO2 emissions from fossil-based systems, enabling it to be used it as a bridge to a sustainable energy future.
The world’s leading scientists agree that we need to reduce current greenhouse gas emissions by 60-80% in a relatively short amount of time to avoid the more serious impacts of global climate change. To meet the climate challenge, Congress will need to use every option on the table.
A market-based cap and trade system, the expansion of renewable energy capacity, and aggressive energy efficiency and conservation measures are all essential parts of the climate change solution, but in the near term these can only partially supplant our dependence on coal.
Coal currently provides 50% of U.S. electricity, is the most carbon-intensive fossil fuel and a major source of greenhouse gas emissions. In order to transition to a low-carbon economy, we must also invest in carbon capture and storage as a bridging technology to reduce today’s carbon dioxide (CO2) emissions.
CCS involves the capture of CO2 from power
plants and other large industrial sources, its transportation to
suitable locations, and injection into deep underground
geological formations for long-term storage. CCS offers a way to
greatly reduce carbon emissions from electricity generation as we
simultaneously expand renewable energy capacity and increase
The U.S.’s reliance on coal to meet half of our electricity needs presents a major challenge to dramatically reducing U.S. greenhouse gas emissions. While it is clear that “business as usual” will lock the U.S. into an unsustainable and increasingly risky and costly climate future, coal is cheap and abundant and is expected to constitute a substantial portion of the U.S. electricity mix in the near-term. Indeed, existing coal-fired power plants will operate for decades to come and new coal plants are currently being constructed or planned. Without CCS, these plants will emit billions of tons of CO2 over their lifetimes.
CCS provides a bridge between our coal-based energy present and a low-carbon energy future. The widespread adoption of CCS technologies will reduce CO2 emissions significantly and help the U.S. meet near-term energy demand until alternatives can provide sufficient and reliable electricity.
CCS provides a bridge between our coal-based energy present and a low-carbon energy future.
Renewable energy will clearly play a critical role in moving us to a low-carbon future. But the challenge of reducing emissions by 60-80% in the coming decades and simultaneously meeting increasing energy demand is daunting.
Despite recent growth in capacity, renewable energy sources such as wind and solar currently account for just 4% of U.S. electricity generation. Therefore, even with a rapid increase in our use of renewables it is unlikely that the U.S. could meet a major portion of electricity demand.
To be sure, it is essential that initiatives that promote renewable energy use and increase energy efficiency are implemented as quickly as possible. However, with the current reliance on coal in the U.S. and developing world, CCS will be a critical technology for meeting our goals of dramatic CO2 reductions and meeting future energy demands.
Large stationary sources in the U.S. emit 2-3 billion tons of CO2 per year. A recent survey by the Department of Energy estimated that there is on the order of 1 to 4 trillion tons of sequestration capacity in oil and gas reservoirs, coal seams, and saline aquifers. Thus, there is likely space for many decades or more of injection.
The trapping mechanisms in the geological formations being considered for sequestration have stored reservoirs of oil and gas for millions of years. Research and pilot projects have shown that CO2 is highly likely to remain sequestered in well-selected and managed sites. Several pilot and demonstration projects have been sequestering carbon for over a decade, and monitoring systems have not detected any leakage.
Most experts believe that properly conducted CCS projects have risks comparable to those of similar industrial activities such as underground natural gas storage and enhanced oil recovery. These risks can be managed, and should be compared with the risks of continuing to emit large amounts of CO2 into the atmosphere. In order to minimize risks, it will be critical to have adequate regulatory oversight and projects done according to best practices standards. Developing guidelines for siting, monitoring and the long-term care of CCS projects is essential to making these technologies work.
We are not yet in a position to widely use CCS technologies. But, we do know what policies need to be in place to make CCS viable:
### Source : http://www.wri.org ###