This paper shows analysis consequences of the increasing penetration of the Renewable Energy Sources (RES) on the Energy market, especially taking into consideration. Foreign literature overview allows the potential effect of increasing of RES generation in overall energy production to be defined. The main trends may include the Merit Order Effect, a decrease in wholesale energy prices and a strong negative correlation between RES output and energy prices. This knowledge may allow the necessary directions of development and required changes on the Polish energy market to be defined. The consequences of the increasing amount of Intermittent Renewable Energy Sources [IRES] is of the growth of the price volatility on the spot market, which leads to the expansion of systematic risk in the energy market as a whole. An increase in the volatility of energy prices also leads to incurring an increasingly high cost of imbalances aggravating the earnings of obliged vendors. The size of the balancing cost grows along with the increasing share of the production of renewable energy and, in particular, intermittent generation sources such as wind farms. Therefore, there is a need for changes in the functioning of RES in a competitive market. The level of development of the renewable energy market and its growing share suggests that producers of renewable energy should take on more responsibility for the costs of imbalances. Further transmission of this cost to the obliged companies may lead to the permanent loss of their competitive position in the market, in relation to those that are not burdened with this expense.