In June 2021, a special issue of the Latvian Journal of Physics and Technical Sciences (LJPTS) was published, dedicated to the problem of energy transition, as well as sustainable and climate-neutral solutions in the fields of electricity, heat, hydrogen and natural gas. The idea of such a special issue, which would include the latest scientific research in the field of energy, has been on the minds of scientists and publishers for some time. Taking into account the results achieved in the infrastructure and market direction projects of the state research program "Energy", as well as the knowledge gained in more than two years in other local and international scientific projects, the knowledge and research results base was created. The special issue not only summarizes the results of scientific research, but also allows to present to the public the achievements of scientists, research innovations and, in some cases, even the perspectives of their future practical application.