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To: Hawkmoon who wrote (186349)	5/9/2006 12:23:18 AM
From: Wharf Rat	Respond to of 281500

Unfortunately, solar and wind cannot be used as industrial-scale transportation fuels unless they are used to crack HYDROGEN from water via ELECTROLYSIS. The ELECTROLYSIS process is a simple one, but unfortunately it consumes 1.3 units of energy for every 1 unit of energy it produces. In other words, it results in a net loss of energy. You can't replace oil - which has a positive EROEI of about 30 - with an energy source that actually carries a negative EROEI Message 21353633 HYDROGEN is not even an energy source; it’s just an energy storage medium. Yes, we could run cars on HYDROGEN, but where are we going to get enough HYDROGEN to run millions of autos? Either it has to be made either from fossil fuels—which are the source of nearly all commercially available HYDROGEN today—or from water using ELECTROLYSIS. But making HYDROGEN from water takes a lot of electricity; in fact, it takes more energy in the form of electricity than the HYDROGEN will give you later on. Message 21360505 Converting water to hydrogen is done through electrolysis. Scientist David Pimentel has established that it takes 1.3 billion kWh (Kilowatt hours) of electricity to produce the equivalent of 1 billion kWh of hydrogen. (BioScience, Vol. 44, No. 8, September 1994.) 64.239.13.64 It has often been pointed out that we have an inexhaustible supply of water from which to derive hydrogen. However, this reaction, 2H2O + e = 2H2(g) + O2(g), requires a substantial energy investment per unit of water (286kJ per mole).37 This energy investment is required by elementary principles of chemistry and can never be reduced. Several processes are being explored to derive hydrogen from water, most notably electrolysis of water and thermal decomposition of water. But the basic chemistry mentioned above requires major energy investments from all of these processes, rendering them unprofitable in terms of EROEI. Much thought has been given to harnessing sunlight through photovoltaic cells and using the resulting energy to split water in order to derive hydrogen. The energy required to produce 1 billion kWh (kilowatt hours) of hydrogen is 1.3 billion kWh of electricity.38 Even with recent advances in photovoltaic technology, the solar cell arrays would be enormous, and would have to be placed in areas with adequate sunlight energybulletin.net

To: Hawkmoon who wrote (186349)	5/9/2006 11:03:36 AM
From: Wharf Rat	Read Replies (1) \| Respond to of 281500

A late PS...Here's a thought. What about the O2? If that could be captured and used,it would increase the efficiency. Use it to power compressed air vehicles? There are people working on these beasts. ( I thought of using CA in '74, when energy was short and I was beginning my career pushing compressed gases. Thought maybe use it as a storage form or something. Decided I was nuts). Maybe use it in steel mills, whatever,to increase the efficiency of combustion. Use it for medical oxygen. But I still don't think it will break even.