Building a weather station that runs on solar power would seem like the very definition of irony. Either you predict sunny weather or you don't predict anything at all. Of course, that's not true. You use the solar cell to charge a long-term battery and then run the unit off that -- and that's exactly what the manufacturers of the Rainwise MK-III Oracle have done. They say that it will run for 60 days off a single charge, so unless you get a really bad run of cloudy weather, all's good. You'll save a lot of money from the electricity you store up with the Oracle's power cell.
And you'll need it. As personal weather stations go, a brand new Oracle will cost you as much as a used car, but that may well be the price of the battery. Long-running solar cells are expensive, as anyone who's tried to get a new battery for their electric car will know. It's possible that once the battery on an Oracle finally breaks down, it'll be cheaper to buy a whole new Oracle than to get the battery replaced.
But enough about the battery. What exactly can the Oracle MK-III do? For starters, it's a full-featured station. Unlike lower-end stations, it has a rain gauge and a weather vane, so you'll not only get the standard list of features -- temperature, humidity, barometric pressure if you're lucky -- but you'll have a full menu of weather readings to select from.
There are cheaper units on the market that will give you as much information as the Oracle will, but they won't run off solar power, so you'll be paying for electric power and draining the planet of its energy resources at the same time. One of the closest to the Oracle in terms of capabilities is the AcuRite 01512 and it's relatively cheap, too, but it doesn't have solar power.
From the first time we turned on the unit we had problems...If you have any problems or questions their support is by far one of the worst.
My favorite thing about this station is the old-school LED display, which can be read from across the room...I echo the comments about the range sometimes being an issue.
Setting this system up was very easy...does not display heat index...on occasion, when there is no wind, the wind direction display will change for no reason.
If accuracy and durability are important to you, this is the way to go. Wireless, and no batteries to change, too!