Estimating the Energy of Solar and Stellar Superflares

We discuss the current observations of the most powerful non-steady phenomena on solar-like stars. While remaining within even the most extreme solar ideas, it is very problematic to get the flare energy more than (3–5) × 10 34 erg, which is apparently an absolute upper limit for solar-type flares. For explanation of the higher flare energy, about of 10 36 erg, one need to adopt that spots with the magnetic field strength of a few kG should cover more than 30% of a hemisphere. This estimate leads to a mean magnetic field around 1 kG. New observational evidences for a presence of the strong magnetic fields on solar-like stars appeared recently. We discuss to what extent it is necessary to change the mechanisms of convection and dynamo with a corresponding change in the models of the atmosphere. We consider possible ways of solving the problem of the energy of superflares.