Thermionic generators are described herein that include a variety of features that allow the devices to efficiently and effectively convert large amounts of thermal energy directly to electrical energy, such as in the form of currents and/or voltages. For example, the thermionic generators can be used to generate an electron beam from a thermionic emission device, and focus or shape the electron beam in such a way that allows the energy of electrons in the electron beam to be captured and converted to electrical energy.

Thermionic generators are described herein that include a variety of features that allow the devices to efficiently and effectively convert large amounts of thermal energy directly to electrical energy, such as in the form of currents and/or voltages. For example, the thermionic generators can be used to generate an electron beam from a thermionic emission device, and focus or shape the electron beam in such a way that allows the energy of electrons in the electron beam to be captured and converted to electrical energy.

Energy conversion systems that may employ control grid electrodes, acceleration grid electrodes, inductive elements, multi-stage anodes, and emissive carbon coatings on the cathode and anode are described. These and other characteristics may allow for advantageous thermal energy to electrical energy conversion.

Energy conversion systems that may employ control grid electrodes, acceleration grid electrodes, inductive elements, multi-stage anodes, and emissive carbon coatings on the cathode and anode are described. These and other characteristics may allow for advantageous thermal energy to electrical energy conversion.

Energy conversion systems that may employ control grid electrodes, acceleration grid electrodes, inductive elements, multi-stage anodes, and emissive carbon coatings on the cathode and anode are described. These and other characteristics may allow for advantageous thermal energy to electrical energy conversion.

Energy conversion systems that may employ control grid electrodes, acceleration grid electrodes, inductive elements, multi-stage anodes, and emissive carbon coatings on the cathode and anode are described. These and other characteristics may allow for advantageous thermal energy to electrical energy conversion.

Energy conversion systems that may employ control grid electrodes, acceleration grid electrodes, inductive elements, multi-stage anodes, and emissive carbon coatings on the cathode and anode are described. These and other characteristics may allow for advantageous thermal energy to electrical energy conversion.

Energy conversion systems that may employ control grid electrodes, acceleration grid electrodes, inductive elements, multi-stage anodes, and emissive carbon coatings on the cathode and anode are described. These and other characteristics may allow for advantageous thermal energy to electrical energy conversion.

Energy conversion systems that may employ control grid electrodes, acceleration grid electrodes, inductive elements, multi-stage anodes, and emissive carbon coatings on the cathode and anode are described. These and other characteristics may allow for advantageous thermal energy to electrical energy conversion.

Energy conversion systems that may employ control grid electrodes, acceleration grid electrodes, inductive elements, multi-stage anodes, and emissive carbon coatings on the cathode and anode are described. These and other characteristics may allow for advantageous thermal energy to electrical energy conversion.