If your main/only interest is in documenting power outages, and (presumably) the line conditions leading up to and immediately following them, TED is probably not the ideal solution, since all its components are line powered and take a finite (though not very long) time to come back up and start recording data again after a power outage. Details of brownouts down to a level that is not sufficient to shut TED down will be recorded, but outages will be documented only as periods with no recorded data. If you want to use TED for its other capabilities, of course, this may be enough for you. Otherwise, among other options you may want to consider are the power-line diagnostic capabilities of a mid-range UPS unit, which will also protect your computer equipment from adverse effects from the unstable power.