The holy grail of energy production on Earth is a self-sustaining nuclear fusion reaction, the same process that creates energy within stars (the sun fuses 620 million metric tons of hydrogen per second). It produces 10,000 times more energy than burning coal.
Learn the basics of nuclear fusion from this MIT Energy Club video.
Nuclear fusion is an atomic reaction where many nuclear (centers of atoms) combine to make a larger element. This releases a lot of energy because the mass of the combination of nuclei is less than the sum of the individual nuclei. The whole is less than the sum of its parts. The difference in mass is converted into energy per E=mc2. The difference between nuclear fission (the reaction of an atomic bomb) and fusion is that fission splits an atom (heavier than iron) into two or more smaller ones and fusion joins two or more smaller atoms into a larger one.
There is certainly a race to build the first functional nuclear fusion reactor (Voice of America video here). The ITER project (International Thermonuclear Experimental Reactor) is an agreement signed by China, the European Union, India, Japan, Korea, Russia and the United States to design and build an experimental nuclear fusion reactor in the next 10 years. It is based in Saint Paul-lez-Durance, France. Lockhead Martin (United States) is also working on a nuclear fusion reactor with the claim (met with skepticism) that it will be developed within the next 5 years. At the University of Washington, scientists are trying to develop nuclear fusion to power the trip to Mars. The United States government is working on it at the National Ignition Facility (NIF).