Green technology for not only reducing energy consumption but also environmental pollution has become a critical factor in ICT industries. However, for the telecommunications sector in particular, most network elements are not usually optimized for power efficiency. In this work, we propose a green routing method in an IP network for the reduction of unnecessary energy consumption. In addition, it can encourage the use of power generated by renewable energy sources instead of using traditional fossil energy. As a green networking approach, we first classify the network nodes into either header or member nodes according to the quantity of the available renewable energies. The member nodes then put the routing related module at layer 3 to sleep based on the assumption that this layer in the OSI model can operate independently. All of the network nodes are then partitioned into clusters consisting of one header node and multiple member nodes. Then, only the header node in a cluster conducts IP routing and its member nodes conduct packet switching using a specially designed identifier, referred to as a tag. To investigate the impact of the proposed scheme, we conducted a number of simulations using real-world renewable energy statistics and results show that our approach outperforms the existing solutions in terms of energy efficiency to a large extent.