The previous posts are entirely accurate in that there is a great deal of cost associated with pioneering new technologies and that there is a relatively low cost in using oil and burning fossil fuels. I am going to take this in a different direction, though, and focus a bit on why the United States is so dependent on oil. This might sound conspiratorial, but I think that there might be some level of validity present. According to statistics produced, 42% of all oil production is domestic. This is a sizable chunk and this particular segment possesses enough political and economic capital to ensure that their voices are heard in government. They utilize the ability to petition the government quite effectively. The remaining comes from abroad, and in particular what lies in the Middle East, in particular Saudi Arabia. In my mind, the relationship between the United States government and the oil producing nations, such as the Saudi Arabian government helps to make certain that our dependence on oil will not be precluded by investment in new technologies. At this time, the Saudis provide about 13% of our total oil supply. Yet, the amount of oil reserves sitting in the Saudi Kingdom and adjacent to it totals about 255 billion barrels of oil. The amount of oil in the United States is nowhere near that amount, and even if it were, it lacks the institutional capacity to produce this much. This means, that the United States, with its dependence on oil, has to look to the Saudis in order to provide it. There is a reason that the Saudis price their oil in US dollars, the only nation to enjoy that benefit. Additionally, the relationship between the US and Saudis has enjoyed complete stability, even though an overwhelming of the hijackers from September 11 came from Saudi Arabia. In the end, the dependency on oil is what guides our interests in the region. The fear is that if there is an investment in other resources outside of oil, then this oil can be taken by another producing nation such as China. In order to prevent this level of growth and to ensure that there is a steady supply to feed the US dependence on oil, there cannot be a full fledged investment in alternative resources. There is a wonderful movie that articulates this phenomenally well called "Syriana." The relationship between the US and Saudi government and how there might exist a collusion based relationship between the oil business and government policies is brilliantly articulated. This might also help explain why we do not use current technology to move towards alternative energy sources.
I think that to a certain extent we are using current technology to move towards the use of alternative energy sources. It is very difficult to change everything very quickly though. For example, right now we have fully functional and operating energy plants that use coal to generate electricity. It would be very difficult to completely shut down a plant like this and start from scratch. These kinds of things take a great deal of time and money. People need to be trained and this takes time and money as well. We are moving forward, it is just a slow and gradual process.
I would say that the main reason is an economic one. Using technology to move towards alternative energy sources is more expensive than simply using the technologies that we already have. This may not take into account the long term costs of using fossil fuels, but it does reflect the costs that would actually have to be paid right now.
It is likely that we have enough technological ability to make solar and other such energy sources usable on a large scale. However, firms or governments would have to spend a lot of money figuring out how to make those technologies work. In the mean time, we have existing technologies that are relatively cheap for fossil fuel use. This means that it would cost more in the short term to use alternative energies than it would to use fossil fuels.
It is not correct to say that humanity is not already making progress towards alternative energy such as nuclear energy and solar energy. Yes the progress in use of alternative energy may not be as fast as we would like it to be. But this restricted pace is not due to lack of efforts.
Main factor limiting the progress of the growth of use of alternate sources of energy is the limitation of availability of capital resources to set up the required facilities. Also setting up of such facilities requires considerable project implementation time running into several years.
Also the cost of generating and using energy from alternative sources can be quite high for many major applications. For example solar energy may be a good source of energy for some home located in a remote location where no regular electric supply company operates, but it is not economical to set up a solar energy plant to serve the entire electric power requirement of a city.
Then some of the alternative sources of energy cannot produce energy round the clock. Solar energy can be produced only when there is enough sunlight. Similarly wind energy can be generated only when the wind is blowing.
Finally, there is a limit on total availability of energy from alternative sources. For example, the total amount of energy that we can generate from tidal waves will probably be less than 1 percent of the current total energy consumption of the world.