Besides researchers of the electrical engineering, Hungarian inventors and scientists contributing to systems of energy transformation necessary for electric power production with discoveries and inventions also shall be mentioned. These inventions are related to energy transformation of hydraulic power, thermal energy, and nuclear energy.
Today, the UN still recommends to third world countries the hydraulic turbine of Donát Bánki (1859-1922) patented in 1916 . It is suitable for middle size falls and volume flow rate. It makes possible the fast utilization of water as renewing energy source.
In the filed of thermal power plant, László Heller (1907-1986) elaborated a cooling system, named "Heller-System". For air cooling system, he used recuperator elaborated by László Forgó (1907-1985). Therefore, this system is named "Heller-Forgó" system. László Heller organized the Department of Energy Management of the BMGE in 1951, and acted as its first professor.
The peaceful use of nuclear energy is realized in nuclear plants. Hungarian scientists contributed to principles of their basic unit, the nuclear reactor. They also participated in construction of the nuclear and hydrogen bomb during and after the Second World War.
Among them Leó Szilárd (1989-1964) wanted to deal with chain process of neutrons in the UK in the 1930s; it became possible in the USA later. In the USA, he described the system of uranium graphite system in inhomogeneous space. He could publish it after the war only. This time the USA government bought his patent of nuclear reactor elaborated with Enrico Fermi.
Jenő Wigner (1902-1995) deemed as the "greatest Hungarian physicist" was chemical engineer first. In the USA, he elaborated the concept of the nuclear fission with Leó Szilárd in 1939. He also participated in the calculations necessary for placing the first nuclear reactor in service. After the war, he was busy in development of reactor in Oak Ridge, and he was considered as the first "reactor engineer". For theoretical works, Jenő Wigner was awarded with Nobel Prize.
Besides using the renewing energy sources, for solution of the world's long-term energy problems, usage of nuclear energy base on fusion is necessary. It is possible with regulated reactors of fusion. Ede Teller - died recently - contributed to clarification of basic principles of nuclear fusion reactors. He immigrated to the USA before the Second World War too.