For the most part, yes. While you are still using electricity in most cases to run these units, technology has helped them become really efficient over the years. In addition, having a system will actually help you live more sustainably because you’ll be growing your own food. This is always a good way to reduce your carbon footprint overall. They can also help you avoid the single use packaging associated with buying greens at the grocery store. As you look for units, definitely read how they are made and try to seek out efficient options. Some are better than others, and manufacturers will usually put details like this in the descriptions. For instance, some are made from recycled materials or include replaceable pods and lights—all good options.