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the largest source of untapped energy in the world sits unused except for a pilot project in Hawaii a number of years back. when we start building very large floating islands capable of tapping this souce, we will wonder why we never thought of it before...

OTEC Description
The technology for generating electricity from different ocean temperatures is known as "ocean thermal energy conversion," or OTEC. OTEC makes use of the difference in temperature between the warm surface water of the ocean and the cold water in depths below 2,000 feet to generate electricity. As long as a sufficient temperature difference (about 40 degrees Fahrenheit) exists between the warm upper layer of water and the cold deep water, net power can be generated.

Advantages

OTEC uses clean, abundant, renewable, natural resources. Warm surface sea water and cold water from the ocean depths replace fossil fuels to produce electricity.
Suitably designed OTEC plants will produce little or no carbon dioxide or other polluting chemicals which contribute to acid rain or global warming (the "greenhouse effect"). Extensive research indicates little or no adverse environmental effects from discharging the used OTEC water back into the ocean at prescribed depths.

OTEC systems can produce fresh water as well as electricity. This is a significant advantage in island areas where fresh water is limited.

There is enough solar energy received and stored in the warm tropical ocean surface layer to provide most, if not all, of present human energy needs.
The use of OTEC as a source of electricity will help reduce the state's almost complete dependence on imported fossil fuels.

The cold sea water from the OTEC process has many additional uses, including air-conditioning buildings, assisting agriculture, and growing fish, shellfish, kelp and other sea plants which thrive in the cold, nutrient-rich, pathogen-free water.

Disadvantages

OTEC-produced electricity at present would cost more than electricity generated from fossil fuels at their current costs. The electricity cost could be reduced significantly if the plant operated without major overhaul for 30 years or more, but there are no data on possible plant life cycles.

OTEC plants must be located where a difference of about 40° Fahrenheit (F) occurs year round. Ocean depths must be available fairly close to shore-based facilities for economic operation. Floating plant ships could provide more flexibility.

Although extensive and successful testing of OTEC has occurred in experiments on component parts or small scale plants, a pilot or demonstration plant of commercial size needs to be built to further document economic feasibility.
Construction of OTEC plants and laying of pipes in coastal waters may cause localized damage to reefs and near-shore marine ecosystems.

Some additional development of key components is essential to the success of future OTEC plants (e.g., less-costly large diameter, deep sea water pipelines; low-pressure turbines and condensers for open-cycle systems; etc.).

The Basic Process

There are basically three types of OTEC processes: closed-cycle, open-cycle, and hybrid-cycle.

In the closed-cycle system, heat transferred from the warm surface sea water causes a working fluid (such as ammonia, which boils at a temperature of about -28°F at atmospheric pressure), to turn to vapor. The expanding vapor drives a turbine attached to a generator which produces electricity. Cold sea water passing through a condenser containing the vaporized working fluid turns the vapor back into a liquid which is then recycled through the system.

Open-cycle OTEC uses the warm surface water itself as the working fluid. The water vaporizes in a near vacuum at surface water temperatures. The expanding vapor drives a low-pressure turbine attached to a generator which produces electricity. The vapor, which has lost its salt and is almost pure fresh water, is condensed back into a liquid by exposure to cold temperatures from deep ocean water. If the condenser keeps the vapor from direct contact with sea water, the condensed water can be used for drinking water, irrigation or aquaculture. A "direct contact" condenser produces more electricity, but the vapor is mixed with cold sea water and the discharge water is salty. That mixture is returned to the ocean. The process is repeated with a continuous supply of warm surface sea water.

Hybrid systems use parts of both open- and closed-cycle systems to optimize production of electricity and fresh water. See the Natural Energy Lab's OTEC Fact Sheet.

http://www.hawaii.gov/dbedt/ert/otec_hi.html

This is a big stretch, but I remember in my college days reading an abstract stating "If all of the energy of a copper penny could be harnessed, it could power a small city for several years...". The world needs an alternative non-petroleum energy source.

NUKES!

I think the US should make it a goal to be totally free from Middle East Oil. I think it should be one of our top priorities. I think this goal is so important that it should be part of the Office of Homeland Security acting with the Dept. of Energy. I do not feel however government can find a good answer. Too much bureaucracy that just gives money to the wrong people.

What should be done is a prize should be given with an outrageous amount of money attached to those who can come up with provable, easy and cheap to implement forms of renewable energy. The winners would collect their prize as well as hang on to a certain amount of patent rights. One restriction should be however that these technologies can not be shared with foreign powers until the US is converted off oil. That'll piss of the French. I have great faith in our private industry and feel this problem can be solved with a little push in the right direction.

There's actually a pretty easy way to reduce dependence on foreign oil: diesel power, for these reasons:

1. Diesel engines use 35-45 percent less fuel for the same power output as gasoline engines. That means lower CO2 output for the same power.

2. Diesel engines are easily adaptable to run off biomass-derived diesel fuel, which burn much cleaner than petroleum-based diesel fuel (no particulate issues to start with). (After all, the first prototype engine Rudolf Diesel built ran off peanut oil ). There are studies that show we could build 20 mile x 20 mile x 10 foot deep ponds growing certain types of algae that could harvest enough biomass to refine into diesel fuel for every vehicle in the USA and then some! That right there could drastically reduce the need to import oil from outside the USA.

3. Diesel engines are actually preferable for light trucks, SUV's and minivans, vehicles that need lots of torque low in the rev range (the strength of diesel engines).

Middle Eastern oil is cheap oil. That's why we buy it. If we develop other sources of energy that cost more but then chose those sources anyway, the only effect will be that we unnecessarily hobble our own economy. Somebody else will step in and buy the cheap stuff from the Middle Easterners in our stead. The only way to reduce the flow of funds to the Middle Eastern oil holders is to either develop an alternative energy source that is significantly cheaper than their oil (good luck!) or to go over there and kick their asses, take their oil, and then - voila! - no more Middle Eastern oil. Just more American oil that happens to be located in the territories formerly known as the Middle East.