A method for buffering the voltage of an electric system that undergoes transient voltage changes includes the step of placing a new load upon the electric system by electrically connecting at least one electrochemical device to the electric system so that electrical current flows from the electric system to the electrochemical device. Also included are the steps of causing at least one electrochemical reaction to occur within the at least one electrochemical device; varying the new load placed upon the electric system as transient voltage changes in the electric system occur; and changing the electrical current from the electric system to the electrochemical device in a manner that retards transient voltage changes in the electric system that would occur in the absence of the steps of placing, causing, and varying. The step of causing electrochemical reactions may include using water electrolysis to produce a product that is a fuel, and the method may further include producing electric power and delivering it to the electric system. The electrochemical devices used in the method may apply chemical thermodynamics to retard increasing and decreasing electric system voltage transients and cause the transient electric system voltage to remain within a pre-specified voltage range. The method may also include connecting one or more voltage support units to provide electric power.