On selecting the prioritized technology, whether or not that technology can lead to significant reductions of GHG emission is an important viewpoint, together with the scale of impact concerning the scope of applicability, such as the crosssectoral potentials for wider industries, not limiting itself to a single process. Hydrogen, for example, can be used in so many ways, not only as an alternative to fuels for automobiles, which depend heavily on fossil fuels, but also for: a substitute power source for coal and LNG-fired thermal power generation; a reducing agent in steel manufacturing in place of coke, and; by reacting with CO2, as an alternative to crude oil and naphtha used in the petrochemical industry and natural gas used in the city gas, the leading cause of global warming. Power electronics technologies reduce energy consumptions of the entire power grid by improving power conversion and control, and further contribute to improving distributed and digital control technologies, such as the Virtual Power Plant (VPP) that functions as a flexible power regulator and enhances the stability of the grid and demand response (DR) to cater for the fluctuation of power generation from renewable energies. Similarly, energy storage technologies such as storage batteries are also extremely important in accelerating the wider use of renewable energy, the large scale introduction of which has been held back due to fluctuation in output. Energy storage technologies can serve as the power source for electrified vehicles, and increase the capacity factor of water electrolysis devices for hydrogen production connected to fluctuating renewable energy, playing a major role in a shift from the fossil fuel-dependent society to the eletrified society. These technologies will also help achieve "Well-to-Wheel Zero Emissions" in the transportation sector.