As part of an effort to find use for electric energy produced by wind turbines, Basin Electric started a program to produce hydrogen through electrolysis. It is not enough to simply produce hydrogen, there needs to be uses for the hydrogen in order to make the project worth pursuing. Hydrogen can be used to supplement diesel fuel in the combustion process in a compression ignition engine. This research will go over two engines which were tested running different combinations of hydrogen and diesel fuel. The results will show how both engines were able to replace up to 50% of the diesel fuel energy input with hydrogen. This paper will also talk about how the addition of hydrogen affects the combustion process by increasing the peak cylinder pressure by 44% and advancing the peak cylinder pressure by 13° of crank angle.