Night light generator which light up your house

Are you utilising energy from solar panels, but have to store it for the night? 
Here it is now scientists have been developed Thermoelectric Generator which harness the temperature difference between Earth and outer space to produce electricity.. They have developed a prototype which produce enough electricity to power a small LED light. The bigger version of it may produce enough to light a house.

 In this device, the sky facing side of the generator is attached to an aluminium plate sealed by a transparent cover and surround with insulation to keep the heat within it, and the bottom of the Generator attached to an expose aluminium plate that is continuously warm by ambient air.

Engineer Wei li and his colleagues at Stanford University developed this prototype and tested it on December night.

The generator produced up to 25 milliwatt of power to light up an LED.

Maybe in future this device will produce enough power to light up a small area. Yuan Yang, a material scientist at Columbia University, says that this device is useful for emergency backup power or energy for people living off the grid.