Micro Thermoelectric Generator and circuit.

Hello

I have designed a Micro Thermoelectric Generator (μTEG) and now I want to connect it to a simple circuit with only a resistance load (RL) to know the power disipated by this resistance.

I think I set all terminals correctly to connect the circuit with the TEG but the circuit ignores the internal resistance of the TEG, so the TEG is like a ideal voltage source, how can I fix that and get a perfect coupling?

Thanks