The increased availability of natural gas is leading to its expanded use worldwide. Substituting natural gas for coal as a fuel for generating electricity helps reduce the carbon emissions that contribute to climate change because burning natural gas emits only about half as much carbon as burning coal.
But half isn’t zero.
That’s why it’s important to note the recent announcement in the United Kingdom of the next step in building the first full-scale commercial natural gas power plant using carbon capture and storage (CCS).
In the Peterhead CCS project, international oil company Shell and British utility Scottish and Southern Energy Company are teaming up to retrofit a 385 MW natural gas power plant to capture post-combustion carbon dioxide (CO2). Pipelines will take the CO2 to permanent storage in a depleted hydrocarbon reservoir two kilometers under the North Sea. When the project, which received U.K. government incentives, comes online in 2018, it will be able to capture and store 1 million tons of CO2 each year for 10 years.
We typically think of CCS as a technology for coal-fueled power plants. In North America, CCS will be used on a commercial scale at coal power plants under construction in Mississippi and Saskatchewan. Four other U.S. coal power plants using either coal or petcoke with CCS are in the planning phases.
However, applying CCS to natural gas facilities as well will be increasingly important as the use of natural gas grows.
While much attention has focused on the natural gas boom in the United States, production and use are rising worldwide in both developed and developing countries. Some analysts project that natural gas will become the developed world’s dominant fuel by mid-century. BP’s Energy Outlook expects global natural gas use to grow at an annual rate of 1.9 percent through 2035, outpacing the growth of other fossil fuels (oil and coal), with 78 percent of that growth occurring in non-OECD countries.
In the United States, increasing supplies of natural gas – especially unconventional natural gas produced from shale through hydraulic fracturing – have encouraged some power companies to switch from coal. That has helped reduce total U.S. greenhouse gas emissions to the levels of the mid-1990s. However, recent increases in natural gas prices mean that coal-fired generation and emissions are again ticking upward.
While several countries are attempting to replicate the U.S. success at developing shale gas, increased supplies are coming mostly from new conventional reserves in places like Australia, the Eastern Mediterranean, and East Africa. This increased availability comes at a time of great change in the power sectors of countries ranging from post-Fukushima Japan to rapidly growing China and Brazil to African countries making energy access a priority for development.
For example, China is planning to reduce its reliance on coal by doubling the use of natural gas from 2011 levels by 2015. Most of this natural gas will be imported, although the government hopes to increase domestic production through shale gas. South Africa is also looking to make natural gas an alternative to coal, mostly through imports of conventional supplies, but also by increasing domestic shale production.
Whether countries are replacing old coal power plants or meeting new energy needs, these new natural gas-fueled assets will be around for decades to come. While the difference in emissions between combusted coal and natural gas is significant, that reduction alone is not enough to avoid the most dangerous impacts of climate change.
We have technology that allows us to capture up to 90 percent of the carbon emissions from power plants and industrial facilities and safely use that CO2 or store it underground.
Unfortunately, absent a price on carbon, CCS is relatively expensive. We’ll need more private and public research to lower costs and government incentives to help commercialize the technology, especially for natural gas facilities.
The Peterhead CCS project is an important first step toward ensuring that the natural gas power plants being built today are part of the solution to climate change.