Energy-efficient systems are designed to use less energy while still providing the same level of service or output. These systems can be found in various applications, including heating, cooling, lighting, and appliances. By optimizing energy use, they help reduce electricity bills and lower greenhouse gas emissions, contributing to a more sustainable environment. Common examples of energy-efficient systems include LED lighting, high-efficiency HVAC units, and Energy Star-rated appliances. These technologies often incorporate advanced materials and smart controls to minimize energy waste. Adopting energy-efficient systems not only benefits individual consumers but also supports broader efforts to combat climate change.