Harvesting energy from daily temperature swings

in the news the other day:

Technology developed at MIT can harness temperature fluctuations of many kinds to produce electricity.

Thermoelectric devices, which can generate power when one side of the device is a different temperature from the other, have been the subject of much research in recent years. Now, a team at MIT has come up with a novel way to convert temperature fluctuations into electrical power. Instead of requiring two different temperature inputs at the same time, the new system takes advantage of the swings in ambient temperature that occur during the day-night cycle.

Reflected in -sry- DailyMail; even in that tabloid they mention Seebeck effect: