In the literature, extensive researches have been done regarding the remanufacturing in closed-loop supply chains (CLSCs) and energy-saving efforts in the forward logistics. However, despite the importance of energy-saving effort in the remanufacturing process, its relevancy in the context of CLSCs has not been investigated. This study extends the previous literature on CLSCs with remanufacturing into the CLSCs with simultaneous effects of remanufacturing and energy-saving efforts on environmental sustainability. This study investigates a CLSC including one (re-)manufacturer investing in remanufacturing and energy-saving efforts, two retailers competing on selling items, and two collectors competing on collecting used items. Utilizing channel coordination and game theory approaches, we analyze how competitive sales prices and collection rates are influenced by the remanufacturing and energy-saving efforts. This study sheds new light on the CLSC management and provides theoretical and practical insights into the way managers of CLSC utilize to promote both environmental and economic sustainability. Our findings illuminate the importance of remanufacturing and energy-saving efforts in the collection process.