Not every technology bettering our future has to be complicated, some are simple, yet extremely effective. 
One of these kind of technologies has come from some Finnish engineers who have found a way to turn sand into a giant battery.
These engineers piled 100 tons of sand into a 4 x 7 meter steel container. All of this sand was then heated up using wind and solar energy.
This heat can then be distributed by a local energy company to provide warmth to buildings in nearby areas. Energy can be stored this way for long periods of time.
All of this occurs through a concept known as resistive heating. This is where a material is heated by the friction of electrical currents.
Sand and any other non-super conductor are warmed by the electricity passing through them generated heat than can be used for energy.
Source: https://www.sciencefocus.com/future-technology/future-technology-22-ideas-about-to-change-our-world/