There has been a big increase in production and investments in wind turbines and wind farms in last 20 years. New generation of wind turbines is more reliable than from 1980’s are, which necessary condition is energy production is to play an important role among renewable energy sources. Over the last 30 years, the size of wind turbines increased 7 times, as nominal power increased nearly 14 times. At present, turbines capable of producing over 10 MW of power are being developed. The main reason for continued growth of turbines sizes is to minimize the energy cost per kilowatt-hour. However, it is worth remembering that according to the „square-cube law”, there is a maximum size after the surpassing of witch the cost of ever-larger turbines would grow faster than financial gain from the increased size. In this article, authors present energy storage methods and devices for wind power plants and cost-effectiveness of the individual energy storage methods. Authors also present data about energy storage efficiency and groups of energy storage devices for wind power plants such as: compressed-air power stations + gas turbine (CAES), utilizing underground wells, pumped storage power plants, rechargeable batteries (lithium-ion, lead-acid, sodium sulphur, VRB, zinc-flow, zinc-air, zinc-air), flywheels, hydrogen production and storage systems, superconducting magnetic energy storage (SMES), electrostatic storage – electrolytic capacitors.