Grant despite the good points about biodiesel, it is only economically viable as a fuel source due to the cheap oil that we use at the moment, the feedstock for producing biodiesel will need cheap oil in order to be grown then processed into an oil, then there is the transport issue. It is a renewable source of energy and that’s a positive, it’s just that it’s not a cheap source of energy. Certain alternative energy 'sources' may actually have ERoEI ratios of less than one, such most methods of industrially producing biodiesel and ethanol. That is, when all factors are considered, you probably need to invest more energy into the process than you get back.
Other proposed solutions include Canadian tar sands and shale oil but this also requires a large amount of cheap energy to process the tar sands into a useable form, after peak oil we will not have cheap sources of energy.
Nuclear power, despite all the other problems associated with it is not a renewable source. At present, economically viable deposits are regarded as being those with concentrations of at least 0.1 per cent uranium. At this cost level, available reserves would last for 50 years at the present rate of use. With many other countries also building new reactors the supply of uranium will soon be out striped by demand, Price of uranium soars Peak Nuclear anyone? Also the mining of uranium, processing and reprocessing are extremely energy intensive. UK Nuclear clean-up costs likely to soarYou have to mine the uranium, transport it, build reactors, reprocess the waste and add in burial and long term storage. All very energy intensive this is also only affordable due to cheap oil.
Who says nuclear power is clean?
They say that at the present rate of use, worldwide supplies of rich uranium ore will soon become exhausted, perhaps within the next decade. Nuclear power stations of the future will have to reply on second-grade ore, which requires huge amounts of conventional energy to refine it. For each tonne of poor-quality uranium, some 5,000 tonnes of granite that contains it will have to be mined, milled and then disposed of. This could rise to 10,000 tonnes if the quality deteriorates further. At some point, and it could happen soon, the nuclear industry will be emitting as much carbon dioxide from mining and treating its ore as it saves from the “clean” power it produces thanks to nuclear fission.
Biodiesel, tar sands and nuclear will help with us lessen the blow of expensive energy, but non of them are long term economical solutions to the problem. Methane hydrate is a huge energy source but the dangers of destabilizing them could leave us facing a global warming threat many times greater than the current one.
Methane hydrate news at Energy Bulletin |