Net-zero emissions energy systems

The good news is that around 3/4 of CO2 emissions from human activity involving fossil fuels and industry are relatively easy to address. The bad news is, 1/4 of emissions sources, a fraction too large to ignore if the world is to meet its targets for climate change mitigation, are going to require significant innovation and ingenuity to solve, according to the paper, Net-Zero Emissions Energy Systems, published today in Science.

These difficult-to-decarbonize energy services include aviation, long-distance transport, and shipping; production of carbon-intensive structural materials such as steel and cement; and provision of a reliable electricity supply that meets varying demand. Moreover, demand for such services and products is projected to increase substantially over this century. The long-lived infrastructure built today, for better or worse, will shape the future.

UKCCSRC Deputy Director for Capture, Prof Paul Fennell, a collaborator on the paper, said “Most of the emissions of CO2 in the world could be addressed relatively simply.  For example, light vehicles could be electrified (in a world with a lot more renewable energy or nuclear), though trucks are very difficult to electrify.  However, there are some emissions which are much more difficult to get rid of.  The cement industry releases CO2 as an intrinsic part of the chemical process which produces cement clinker. Similarly for Iron and Steel manufacture, it is very difficult to eliminate the CO2 which is produced by the chemical reactions which produce Iron. This review looks at ways to attack these last few very very hard to eliminate sources of CO2.”  It will not surprise members of the UKCCSRC that CCS was one of the key technologies necessary to decarbonize many industrial processes.

The paper takes its origins from a workshop in Aspen, Colorado, which brought together around 30 experts, from diverse backgrounds, who are all tying to tackle the hardest to get at CO2 emissions. During the workshop, the attendees debated which areas of research are most critical and came to a consensus on the priority areas for long-term research and development.

Senior author of the paper Ken Caldeira, Carnegie Institution for Science, said “Possibilities that the team analyzed include, but aren’t limited to, the synthesis of energy dense hydrogen or ammonia-based fuels for aviation and shipping, new furnace technologies in the manufacture of concrete and steel, and tools to capture and safely store hydrocarbon emissions.”

But the costs of implementing and scaling up these technologies to overhaul the transportation, construction, and energy storage industries will present hurdles, they warn. Plus, it will be necessary to overcome the inertia of existing systems and policies to create something new and better.

“We don’t have a crystal ball to foresee what technologies will exist a century from now,” Caldeira continued. “But we know that people will want buildings, transportation, and other energy services and we can try to design our energy system so that it is able to take advantage of new inventions as they come along.”