edd17

The gallium doesn’t get used up but the aluminium does; I don’t know how easy it would be to extract the gallium back out of the aluminium afterwards, or if it would need to be removed for the aluminium to be reprocessed but that would be a major obstacle in this systems development. Another idea is to produce the hydrogen at a large plant and then store it in a crystal lattice; it is easier and safer to store it in this way then using simply using pressurised hydrogen. A new type of lithium compound has been developed and is talked about here

Anyone who has ever seen the thermite reaction knows that a lot of energy can be released by the oxidation of aluminium, and I think that this process is a similar (using water as the source of oxygen and the hydrogen being left over). The amount of energy used to produce the aluminium used needs to be taken into consideration though. Bauxite is the most commonly used aluminium ore and is comprised mostly of aluminium hydroxide, which needs to be heated to produce aluminium oxide (aluminium hydroxide at a lower energy state then aluminium oxide), and the aluminium is then extracted from the aluminium oxide using electrolysis, a very energy intensive process and electricity use can amount to up to 40% of the costs of production (the reason so much energy can be released is that so much energy has to be put in). The article mentioned the recycling of the aluminium oxide produced, which would skip the process of converting aluminium hydroxide into aluminium oxide and reduce the amount of energy used. However the amount of energy consumed to produce the aluminium is equal to the amount of energy released (not considering efficiency and transport), as you are starting with aluminium oxide and finishing up with aluminium oxide, and another source of energy will need to be used to supply the electricity for electrolysis. This is another example of how hydrogen can only be used to transport energy, not as an energy source. Breaking down water through electrolysis may be more efficient, although the electrolysis of water can be very inefficient and steam reforming (production of hydrogen from hydrocarbons) is usually much cheaper. This can be a very efficient way of transporting energy for use in vehicles and other things which usually require petrol engines, but the actual energy input will still be from some other form of energy (hydropower is often used to supply the energy for aluminium production).

New Scientist has published a list of myths (and answers to them) about climate change here

Instead of citing a report by the Australian Uranium Association, you could have linked an actual report from the UN; http://www.who.int/ionizing_radiation/chernobyl/chernobyl_digest_report_EN.pdf Nuclear fission is an important source of power today, and can continue to be so in the future; but i think it is illogical to think that the Chernobyl disaster has not and will not have detrimental effects on the health and economy of the areas contaminated.

It is undeniable that increased levels of carbon dioxide (or any greenhouse gas) in the atmosphere will increase the amount of heat retained in the atmosphere; the electromagnetic radiation reaching the earth from the sun is (pretty much) spread over the entire spectrum, from radio waves to x-rays. The radiation which is not blocked by the atmosphere reaches the surface of the earth and heats up the ground. This heat energy is then given off in the form of infrared radiation (the frequency of the radiation is proportional to the heat of the object) and is then directed back up into space. Different gasses will always absorb a specific range of radiation (due to the bonds between the atoms and the arrangement of the electrons) the bonds found in carbon dioxide and a number of other gasses are such that they absorb radiation in the infrared range of radiation. This means that they will absorb infrared radiation (in which most of the energy of energy is lost) and heat up... hence global warming. The exact magnitude of the effect of increasing the amount of greenhouse gasses in the atmosphere is disputable. It could be calculated from the amount of greenhouse gasses released into the atmosphere how much more energy would be held in the atmosphere and how much the average temperature of the atmosphere would be raised but the effect on weather would be much harder to predict.