Nowadays energy efficiency is one of the most important issues in sustainable supply chains. In addition to increasing environmental awareness, governments can also act on behalf of their citizens by trying to get businesses to produce energy-efficient products. Therefore, we consider a structure consisting of a manufacturer and the government. The manufacturer produces a product that consumes a certain amount of energy when used to perform a specific task. We assume that consumers are sensitive to the cost of the energy that they must use for that task. The government imposes a tax on the price per unit of energy to motivate the manufacturer to produce products that consume minimum energy. This problem is introduced and solved for the first time. There are two decision-makers in this structure, so we use the game-theoretic approach to obtain the best decisions for the government and the manufacturer. The most important result of this study is that when the government imposes a tax on the price per unit of energy, consumer demand for the product decreases. Therefore, the manufacturer decreases the energy consumption of its product to reattract the attention of consumers. The model proposed in the present study states that when the government imposes a tax on the price per unit of energy, manufacturers are motivated to produce energy-efficient products. We also found that the policy adopted by the government will increase the stability of the market against the sensitivity of consumers to the cost of energy