This Act establishes a new regime for supporting renewable energy sources (including wind energy, solar energy, hydropower, aerothermal, geothermal, and hydrothermal energy derived from biomass, biogas, agricultural biogas, and bioliquid - art. 2.22), with the aim of stabilizing the long-term support system and preventing unchecked increases in electricity prices. The Act also incorporates the Renewable Energy Directive 2009/28/EC into Polish law and aims to help Poland meet its 2020 goal of producing 15% of its energy from renewable sources. While future investments will compete for support through an auction system, the Act will give continuous support to the majority of existing installations (in service by or before 31 December 2015) through certificates of origin.