You'd be better off buying a few solar panels.
What you are thinking of can be done, there are power plants that use this technology to generate power. However, its really not that simple. You're working with VERY hot things and VERY high pressures to get any real power out of it. This ends up meaning expensive components. Also, a turbo is going to be horribly inefficient at capturing that energy. Most likely less than a solar PV panel. Steam turbines usually have a large number of turbines to capture as much of the steam energy as they can. Here is an example:
Honestly, a much better idea is to head over to EcoRenovator and take a look at their
60+ energy saving tips list that is the equivalent of the 100+ hypermiling / 65+ ecomods lists we have here on EM. There is way more you can do on the conservation side before even considering generating your own power.