Clean and sustainable energy solutions are the main motivation for my research. Geothermal energy meets the criteria since it exists everywhere on the planet but at 5-10 km depth underground. Nowadays drilling technology can’t drill to these depths economically and hence drilling innovation is mandatory. Recently, plasma comes in business as one of the cheaper and faster drilling techniques with different approaches. Our research focuses on understanding the microscopic processes in rocks under microsecond high voltage (few 100 kilovolts) pulses. The breakdown of rocks under this voltage creates plasma channels with slow density and the resultant high pressure leads to the rocks fracture. No clear understanding of the fundamental process has ever been figured out and this is our main goal within this PhD at the GEG group.