What are the grand challenges that await engineering solutions in the century ahead? How can engineers put knowledge into practice to ensure sustainability, health, safety and quality of life for the generations to come?
The U.S. National Academy of Engineering (NAE) assembled a diverse panel of experts from around the world to answer these questions. The members are some of the most accomplished engineers and scientists of their generation. They proposed fourteen 'challenges for engineering' that they consider both achievable and sustainable.
It is significant that the first three challenges mentioned in the report are all related to energy. This focus is immediately apparent in the report’s Introduction: 'The Earth is a planet of finite resources, and its growing population currently consumes them at a rate that cannot be sustained. Widely reported warnings have emphasised the need to develop new sources of energy, at the same time as preventing or reversing the degradation of the environment.' The expert panel saw three main engineering challenges that could satisfy this need:
The energy of the sun’s radiation on earth is abundant, but the challenge is how to convert this solar energy into a useful form in an economic way. Today, electricity from solar energy still costs roughly three to six times more than the average grid electricity price.
According to the expert panel, engineering could boost solar energy in three ways:
Along with making use of the sun’s radiation for our energy needs, we could also artificially re-create its power source, namely nuclear fusion. Although the theory of nuclear fusion has already been well known for more than fifty years, using fusion for commercial purposes stretches the limits of current engineering ingenuity.
A major test facility, the International Thermonuclear Experimental Reactor (ITER) is currently being built in the south of France. It aims at producing a long pulse of energy release out of the fusion of deuterium and tritium. The required deuterium can be produced from water. Tritium — a radioactive material — can be produced out of lithium. The fuels are heated to a plasma state and compressed by magnetic forces.
It is hoped that the new test facility will enable the solving of various technical and safety issues. Among other things, superconducting magnets will have to be improved and advanced vacuum techniques developed. Methods will also be needed for confining the radioactivity from fast flying neutrons within the reactor. Moreover, releases of radioactive tritium fuel will have to be prevented. In a later stage, one of the challenges will be to replace tritium with a new generation of fuel and thus reduce radioactivity by several orders of magnitude.
Until engineers are able to overcome the practical barriers of solar power and nuclear fusion, fossil fuels will remain the primary source of energy. To limit the impact on climate change of this continued use of fossil fuels, methods are being developed for capturing the carbon dioxide from combustion emissions and storing it underground.
The NAE panel of experts sees three principal avenues to be investigated for carbon capture:
For carbon storage, the following tracks are being investigated:
Apart from the above tracks, new techniques for sequestering carbon dioxide could solve both the capture and the storage issues. One such proposed technique is to fix carbon dioxide in limestone rocks.
Harvard geoscientist Daniel Schrag declares in the NAE report that the chances of success for carbon sequestration are high. 'Scientific and economic challenges still exist,' he declares, 'but none are serious enough to suggest that carbon capture and storage will not work at the scale required to offset trillions of tons of carbon dioxide emissions over the next century.'
Website on the Grand Challenges of Engineering by the U.S. National Academy of Engineering (NAE)Log in to post comments