The fundamental issue according to the ESF is that total annual global energy consumption is set to at least double from its current level of 14 TW by 2050, while fossil fuels will start to run out. The use of fossil fuels also produces unacceptable levels of carbon dioxide, causing global warming and has disastrous effects in many areas, such as food production.
Apart from solar energy, the shortfall can only be made up by renewable sources such as wind, along with the other non-fossil, non-renewable fuel source of energy, nuclear. But these will be unable to satisfy the predicted increased energy needs and certainly will not be able to replace fossil fuels entirely, even for electricity production alone. Another problem is that they will not readily yield stored fuels. Without an unexpected breakthrough in electricity storage, there will be a continued need for fuels for around 70% of total global energy requirements, ESF says, particularly in transportation, manufacturing, and domestic heating. Electricity only accounts for 30% of global energy consumption at present.
However solar energy is plentiful since enough reaches the earth's surface every hour to meet the world's annual energy needs. The problem lies in harnessing it. Nature has perfected, in photosynthesis, a highly efficient and flexible means of doing this across a wide variety of scales, from isolated bacterial colonies to large forests.
Substantial progress has been made recently, particularly in Europe, in understanding and mimicking these natural processes, sufficient for scientists to be confident that they could use them to produce fuels on a commercial scale.
A recommendation from ESF says the focus of research should be on drawing inspiration from biological systems for the creation of both natural and artificial solar energy conversion systems that allow in the long run for a stable and sustainable energy supply. There should also be an aim to reduce the human ecological footprint and thereby increase the global ecological capacity using technology that is environmentally clean, for instance by conversion of carbon dioxide back into fuels in a cyclic process.
The ESF task force is recommending that three parallel avenues of solar energy research for generating clean fuel cycles should be pursued: - Extending and adapting current photovoltaic technology to generate clean fuels directly from solar radiation. - Constructing artificial chemical and biomimetic devices mimicking photosynthesis to collect, direct, and apply solar radiation, for example to split water, convert atmospheric carbon dioxide and thus produce various forms of environmentally clean fuels. - Tuning natural systems to produce fuels such as hydrogen and methanol directly rather than carbohydrates that are converted into fuels in an indirect and inefficient process.
Although the principal products of photosynthesis in plants and bacteria are carbohydrates, some hydrogen is produced in certain algae and bacteria, providing a basis for genetic modification to increase yields, and for the creation of suitable artificial systems, ESF says.
