You have many options when it comes to energy-efficient lighting to save money on electricity costs. Choose from LED, fluorescent lighting, or outdoor solar lighting. Replacing your existing high-powered lights would be a great start. Conventional incandescent lighting is only 5-10% efficient in producing light. The remaining 90% produces heat. Imagine have a heater that was 10% efficient at producing heat and 90% efficient at producing light…. We would never consider that to be a viable source of heat.