"...can boost 300 to 400 millivolts power to 3 to 5 volts".
Power? Volts? Boost? Huh???
In common vernacular of an EE you refer to voltage as power with the understanding that there is current being supplied. EG This device is powered by a 9-volt battery. So the the use of power in TFS and TFA is not out of line.
The paragraph form TFA is:
All these ambient energy sources, such as the difference in temperature in a pipe carrying hot water and the outside air, can generate 300 to 400 millivolts, which isn't enough to power anything. TI has built an "ultra-low powered" DC-to-DC switching converter that can boost this power to 3 to 5 volts, which is sufficient to charge a battery, according to Niranjan Pathare, senior marketing development manager at TI.
Also while current is a needed aspect, the level of voltage is a defining factor in electronic design.