They work great in colder water for kelp and habitat, just not for coral. Not everyplace is set up for recycling! The energy it takes to transport and store them is a big factor! Real scientists are now looking at all factors in a cycle and a new study shows your full SUV is less damaging than a train station and its systems if you consider the impact of construction! Not everything is as simple as ALGORE would have you think, including North Korea!