Abstract— Since renewable resources have different characteristics and mandatory output unlike conventional sources, the existence of renewable distributed generation as a part of the network represents a new challenge that needs different handling of loss allocation techniques. In this paper, a new methodology is introduced for handling transmission power loss allocation techniques for loop networks comprising renewable distributed generation. This necessitates an investigation of the effect of integrating renewable distributed generation on loss allocation among individual generators and loads of the network using different loss allocation techniques. Also, the effects of separate and simultaneous time variation of both loading and renewables generation are analyzed. The paper implements two different techniques for loss allocation, which are based on circuit laws and power flow solution. The techniques are applied on IEEE 14-bus system, where Photovoltaics and wind sources are optimally allocated. The results prove the considerable effect of different levels of loading and renewables output power on loss allocation. The proposed methodology maintains the accuracy of loss allocation with considering the time variations of loading and renewable generation. Also, it overcomes the problem of huge calculations for large systems and thus, reduces time consumption.