I've got a question I hope you can help with, my aplogies if this is in the wrong section. To cut it short I'm currently designing a vehicle system for my college project. Part of the system is to store heat produced from the engine to be used at a later time.
I'm finding it quite difficult to find clear information regarding suitable heat storage information.
I know it's possible as the Toyota Prius uses a container to store heated engine coolant at temperature for up to three days.
From what I can gather, water is the most efficient for storing heat energy, and a vacuum flask(?) is the best for insulating the heat.
The average coolant temperature of an engine is around 100 degrees C, and ideally I'd like to keep this heat stored for the longest possible period within reason (regarding practicality for price and space available in a car).
I've heard about some kind of salt that is good for storing heat but couldn't find any more information on the subject.
If anyone has any ideas or knows of any more suitable materials/containers it would be really helpful.