Mapawatt has not personally tested Wattvision. Based on our research, we do recommend it for all users who have a compatible meter, and the meter is within 50' of your home's wifi network.
The quote below is taken from Tom Harrison from the Amazon page for Wattvision. Tom is a trusted source for Mapawatt and is the author of Five Percent: Conserve Energy.
"Enter Wattvision. Using a simple velcro strap, it wraps around your meter and gives you a clear and positive feedback when it's reading the meter correctly. Many meters have a digital output, some older meters are still the spinning-dial analog ones. Either way, setup at the meter is a snap. But the really cool part of Wattvision is the service part of it. You connect the meter-bit to a tiny little box that plugs in. And when it plugs in, it connects (magically, it seems) to your home's wireless network with minimal setup. No other wires, no mess, no electrician -- just works. Once you have set it up, it sends data over the Internet to a private site you can log into to get your account through a web browser.
The magic is that you can see both momentary usage, and trend data over time. And it's on the Internet, so from anywhere. The interface is simple but highly useful. Got a smartphone or tablet? It works with that, so you can walk around and see when you turn on something exactly how much it uses. You get weekly email updates (which honestly, could be a little more useful), can set up alerts, and you can even hook it up to other internet-connected displays.
I have had mine now for several years, and it just keeps working. It's there when you need it, and not when you don't. Having compared to multiple other energy monitoring devices, I highly recommend Wattvision."
