The efficiency of organic fuel will increase in short-term perspective. <...> A further future holds renewable energy sources. But we must work on them today, otherwise we are going lag behind forever. This is where I see such important areas as solar energy and geothermal energy. But gradual transition to petrothermal energy is even more promising. It uses heat from dry rocks at depths of 3 to 10 kilometres. That is where temperature reaches 350 degrees Celsius, and it is estimated to be an inexhaustible source of heat. At the very least, it will be sufficient for the entire time of humanity’s existence, taking into account the complete life cycle of developed civilizations. The idea of extracting deep heat was proposed by Tsiolkovsky in 1897. But it is only today that there is an opportunity to realize it — Sergey Alekseyenko, Academician, Member of the Department of Energy, Mechanical Engineering, Mechanics, and Control Processes, Russian Academy of Sciences.
Recent price calculations reflect a bigger role for solar energy in the future. In recent years, the industry has seen a tenfold reduction in the cost of energy supply to users. We are going to supply 1 terawatt of solar energy by the middle of the next decade — Martin Green, Professor, University of New South Wales (UNSW); Director, Australian Centre for Advanced Photovoltaics (ACAP).
Renewable energy sources are very important for sustainable energy development, for rapid energy development. Oil and gas, especially gas, will remain important, but the share of renewables will increase: wind, solar, hydropower, nuclear power, biomass energy; and that is going to take up to a third of the total energy consumption structure. The future is in combining different types of energy — Xiansheng Sun, Secretary General, International Energy Forum (IEF).