Sala Seminarios IFIC (Edf. Institutos de Investigación) Jueves, 23 de Abril de 2009 a las 12:00 PM
Resumen
A large increase in world energy use is expected. The developed world could survive perfectly well with less energy, but an increase is needed to lift billions out of poverty in the developing world, where a quarter of the world’s population lack electricity. Meeting future demand will be an enormous challenge. Reducing demand must be an imperative, but with the world’s population set to grow 20% by 2030, it is unlikely that greater efficacy will produce an actual decrease in energy use, unless living standards stop improving in the developing world.
Currently fossil fuels provide 80% of the world’s primary energy. Burning fossil fuels is generating potentially catastrophic climate change, and is unsustainable as they won’t last for ever (oil will be depleted first, then gas: it is said that there is enough coal for over 200 years, but that is with current use - use is growing at 4.5% p.a., which turns 200 years into 50 years). The world will probably burn the remaining fossil fuels, on a time-scale that is short compared to the hundreds of years that CO2 stays in the atmosphere. Developing the technology to capture and store CO2, and then (if feasible) rolling it out on the largest scale reasonably possible, must therefore be a priority. Meanwhile we must expand the use of low carbon sources of energy that will be needed when the fossil fuel era ends. These energy sources should include wind, marine, bio, and geothermal energy, but they will not provide anything like enough.
In principle the only sources that can replace a large fraction of the energy provided by fossil fuels are solar and nuclear. There is enough solar energy to meet all the world’s needs, but - if it is to play a major role - the cost needs to be reduced and means of storage and cheaper transmission developed (concentrated solar looks especially promising as it produces heat which can be stored in molten salts, and - at high enough temperature - produce hydrogen). Nuclear is already widely available and needs to be expanded now, but if there is a major nuclear renaissance, relatively cheap uranium will become scarce in the second half of the century. The conventional nuclear age can, and should, be prolonged by adopting more efficient fuel cycles, but we must start preparing for the post cheap uranium age now by developing plutonium fast breeders, thorium reactors and fusion as a matter of urgency.
The political and economic challenges involved in the transition to a low carbon world will be even greater than the technical challenges.
