New thermoelectric generator, lots of questions

[Greenpower dude]

thermoelectric generator peltier

Hey every1!

I'm building a thermoelectric generator at the moment with a 560W peltier chiller and have run into a few problems.

To give a breif run over the design. The generator is just a large TV dish which has been covered with aluminium foil to reflect the light onto a heat sink that is glued to the peltier with another heatsink and fan attached to the other side.

With the generator head, I'm affaid it might get too hot for aluminium heatsink. Anyone know if a 80cm dish focusing light onto a small area will generate enough heat to melt aluminium?

Also another thing about it is that the dish must be pointing at the sun all the time. To do this I have decided to power the motors with a few small solar panels/cells. I have seen photodiodes in Jaycar electronics and thought they'd be better than using photoresistors and zenerdiodes. How do photodiodes work?

Finally I come to a problem with the power out put. Because at each part of the day the peltier will be generating different amounts of power. I was going to use zener diodes but a friend of mine told me that it would waist too much power, instead he told me about a chip which i have forgotten the name of, I'm just wondering if there is anyone who can tell me what the name of the chip is, and if there is another way to stableise the power output voltage wise?

Greenpower Dude

 

[DMan]

thermoelectric generator

I'm higly sceptical of your aproach to energy generation. But I wish you as much succes as possible. Here is some math:
80 cm dish has the area of about 2m^2, and te sun provides about a 1kW per m^2 od energy. So in ideal conditions you could generate 2kW. When the non ideal reflection properties od aluminuim is taken in account you end up with a lot less. Peltier element only has the efficiency od 5-10% so you are allready in very low numbers of generated energy.

If you look at this numbers you can see that 80 cm dish won't melt aluminium and that your system will use more energy for the sun follower as it will generate.

Best wishes and regards DMan

 

[Greenpower dude]

large thermoelectric generator

What would be an ideal reflector?

 

[DMan]

building a thermoelectric

An ideal reflector would be a mirror or even better a set of mirrors focusing on one point.
But the majority of inefficancy of your sistem is coused by the Peltier element. For example photovoltaic cells have the efficiency of obout 12-15% ehich is 2-3 times better than Peltier.

 

[Greenpower dude]

peltier element generator

I'll give it ago, see if it works and if it doesn't turn out to my new expectations, I'll just scrap it and salvage spare parts.
Who knows what a mirror lined satellite dish will come in handy? :lol:

But thanks for all the help and I'll be getting back later to tell everyone how it worked.

Green power dude