I understand, but how will this device save power? Is it by...

I understand, but how will this device save power? Is it by turning the light fitting off? As i said the world uses Hps and metal halide, the yellow being high pressure sodium and the white being metal halide, the only way i can see these light's being able to dim is by changing the ballast and ignitor to dimming technology, it can not be done any other way unless they plan on doing a complete fit out with new dimmable led lighting, other wise its not only going to cost $100 plus install it will more likely cost up to $900 per light or about $400 if they only decide to replace the ballasts and ignitor, in that case maintenance wont change and there will be no cost saving on maintenance, i seems some critical info is missing from Gridcomm