Quote:
Originally Posted by RedDevil
All true.
What I saw from testing my own small TEG is that the voltage is anything but constant (it varies with the temp difference, obviously); also the power output from said small TEG was too tiny to bother with.
Much better at cooling/heating than at converting a temp difference back to electricity.
A MPPT voltage regulator as used with solar panels is the way to go imho.
It will be some time before the weight/cost/complexity of this would be overcome to a level where it can compete against a battery pack, charged at home or by a solar panel on the roof/hood. Which is what I'm busy with now  |
I think Alphabet's TEGs are already mostly there. There are experimental TEGs with more exotic materials + nanotechnology but they are experimental and probably will cost a lot. What Alphabet claims to bring is silicon based TEGs (read: cheap) that can work at higher temperatures. There were already high temperature TEGs around but they were extremely expensive and hard to find.
A few years ago I posted a link to a commercially available integrated solution much like this one, but it used 300C limited TEGs so it is probably down 50% on efficiency compared to these, which can run at something like 600-700C, and that unit was capable of producing 300W in a reasonable sized package. So you could use a smaller unit to get 300W (making the alternator redundant), which would already be a big help for fuel economy.
The tricky thing is of course that TEGs have pretty high internal resistance and producing different voltage at different temperature, so you definitely want a voltage converter to extract the power effectively.