Primary energy is energy contained in raw fuels or other naturally occurring forms of energy before it undergoes transformation or is put to a use. It is a measure of the energy potential of a source, what could be used if conditions were ideal - which they are however not, for the largest part. Electricity derived from fossil fuels e.g. loses around 2/3 of its energy potential in the transformation process. In other words: it needs roughly 3 parts fossil fuel to generate one part of electric energy. After transformation, energy is delivered to consumers as consumer or final energy, with additional losses due to transportation. Primary energy can be re-calculated from consumer or usable energy with the help of primary energy factors, if these are known. PHPP contains a list of primary energy factors for non-renewable energy services. The new certification categories are among other things concerned about renewable primary energy.