Centauri's Thoughts

Part of the energy problem based on hydrogen (for one) is the efficient splitting of water into hydrogen and oxygen.

From PhysOrg.com:

Hydrogen will be one of the most important fuels of the future. It would be ideal to obtain hydrogen by splitting water instead of from petroleum. However, the electrolysis of water is a very energy intensive process, making it both expensive and unsustainable if the electricity necessary to generate it comes from the burning of fossil fuels. Photolysis, the splitting of water by light, is a highly promising alternative.

The basic process of electrolysis is to bring the hydrogen and oxygen ions out of the water as a gas.

The biggest hurdle to overcome in the photocatalytic splitting of water to date has been the lack of a robust catalyst that oxidizes water. In fact, the best known catalyst, which very effectively oxidizes water when irradiated with visible light, is a manganese-containing enzyme in the photosynthetic apparatus of living organisms.

An efficient catalyst could mean an inexpensive way to split water, and possibly "on-demand" splitting, which would be rather handy, as the need for hydrogen storage would be bypassed altogether.

source: Catalyst for water oxidation adopted from plants: a means for energy-efficient production of hydrogen?

Solar energy directly or indirectly provides the energy production on this planet in one way or another (save geothermal), either by the production of biomass, fossil fuel, or the driving of weather for hydro and wind power, or solar arrays.

The main problem with direct solar power is what to do about nighttime. While some battery systems might help in this step, it would be expensive to have batteries that could keep a house powered all night during the absence of light (and even moreso for the power companies).

The use of solar power is one part of this idea, and now comes the second part:

Electrolysis of water (as is done in science class) isnt very efficient, and the use of high temps to help the efficiency along doesnt make this process very cheap or safe for a home user. Also, the water usually needs to be made conductive by either adding salt or an acid or a base (none of which desirable for humans or metals).

Daniel Nocera, the Henry Dreyfus Professor of Energy at MIT, has an interesting solution to this, namely, a new catalyst consisting of cobalt metal, phosphate and an electrode, placed in water. This can then be used to power fuel cells (which uses hydrogen and oxygen to produce electricity giving only water as its byproduct).

Inspired by the photosynthesis performed by plants, Nocera and Matthew Kanan, a postdoctoral fellow in Nocera's lab, have developed an unprecedented process that will allow the sun's energy to be used to split water into hydrogen and oxygen gases. Later, the oxygen and hydrogen may be recombined inside a fuel cell, creating carbon-free electricity to power your house or your electric car, day or night.

Read the whole article here.