(10) In its resolution of 25 September 2007 on the Road Map for Renewable Energy in Europe (5), the European Parlia- ment called on the Commission to present, by the end of 2007, a proposal for a legislative framework for energy from renewable sources, referring to the importance of set- ting targets for the shares of energy from renewable sources at Community and Member State level. (11) It is necessary to set transparent and unambiguous rules for calculating the share of energy from renewable sources and for defining those sources. In this context, the energy present in oceans and other water bodies in the form of waves, marine currents, tides, ocean thermal energy gradi- ents or salinity gradients should be included. (12) The use of agricultural material such as manure, slurry and other animal and organic waste for biogas production has, in view of the high greenhouse gas emission saving poten- tial, significant environmental advantages in terms of heat and power production and its use as biofuel. Biogas instal- lations can, as a result of their decentralised nature and the regional investment structure, contribute significantly to sustainable development in rural areas and offer farmers new income opportunities. (13) In the light of the positions taken by the European Parlia- ment, the Council and the Commission, it is appropriate to establish mandatory national targets consistent with a 20% share of energy from renewable sources and a 10 % share of energy from renewable sources in transport in Community energy consumption by 2020. (14) The main purpose of mandatory national targets is to pro- vide certainty for investors and to encourage continuous development of technologies which generate energy from all types of renewable sources. Deferring a decision about whether a target is mandatory until a future event takes place is thus not appropriate.