Sure, all of those features are good for the meter's own safety, but why are they here on AutoblogGreen? That would be because they are solar powered. Why not? The meters sit outside all day anyway, so they might as well be collecting the energy that the sun is giving off. Solar power plus cellular calling also makes the machine wireless, which allows them to be placed wherever necessary and cuts down on unsightly and not-so-environmentally friendly cables.
[Source: Eastbourne Herald via Engadget]