Bad news my friend, it is pure bunk. take one apart and you will quickly see it does nothing but light a light.
the best way I know to cut electric cost is
1: switch over to low voltage. This is a fun project and you can save 20% just by using step down transformers to allow the use of 12-24 v lighting and a lot of other products that are available.
2: Make the move to solar, unbelievable jumps in technology has made photovoltaic very cost effective. Especially if you are in one of the areas by zip code that are offering city, state and federal grants for making the switch. The govt. is very concerned about the brown outs that overload the production like in California. We have it on a very small scale in Texas compared to them but many business’s like American Airlines are required to cut power use during peak hours. They have done things like 100 ton ice machine. They make ice all night and in the heat of the day use it in an heat ex-changer to offset running all the chillers. I had Tesla install 7.8 kilowatt pv on my house to offset my electric use, and they came back with a 30 year lease with $0 out of pocket up front and $105 a month. Many neighbors are paying $300-$600 and more per month depending on the season. The solar electric providers have a “net Metering” program where they buy from me at the same rate they sell. So if I am making more than I use they buy from me. Sweet! I am in the process of installing solar wifi cameras in my HOA, simple install with no wiring and the solar is so good it keeps the lithium batteries charged so I can run the cameras s24/7 and then record on the cloud dvr off wifi.