It’s fairly straightforward to understand that energy efficiency programs offset combustion generation emissions through avoided energy use. It would’ve taken GP one glance at Wikipedia, if questioning the environment benefits.

https://en.wikipedia.org/wiki/Energy_Star

> More than 75 product categories are eligible for the ENERGY STAR label, including appliances, electronics, lighting, heating and cooling systems, and commercial equipment such as food service products. In the United States, the ENERGY STAR label often appears with the EnergyGuide label of eligible appliances to highlight energy-efficient products and compare energy use and operating costs.

> One of the most successful voluntary initiatives introduced by the U.S. government, the program has saved 5 trillion kilowatt-hours of electricity, more than US$500 billion in energy costs, and prevented 4 billion metric tons of greenhouse gas emissions. Elements of the ENERGY STAR program are implemented in Canada, Japan, and Switzerland.