Small Steam Turbines

Where have you looked so far?

Maybe here: GlobalSpec.com

Engines Page of Reliable Steam Engine Co. Maker of Steam …

HVAC/R engineering - Small steam turbine - Eng-Tips Forums

Steam Turbine, Steam Boiler, Power Plant, Steam Power: Forum

Why? How are you getting/making the steam?

Solar Steam generated by solar concentrators.

Instead of turbines, you might consider small steam engines. There is a lot of literature on them, such as Live Steam, in sizes similar to residential needs.

G.A. Steam engines fit the size better and operate easier. Besides, the people are not home at night and when there is no sun. A small steam engine needs a big solar concentrator and probably a lot of bypass power from.....?

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http://www.mamod.co.uk/ (usual disclaimer).

Steam generation is not particularly easy nor inexpensive and steam turbines, like most turbines, are a bit fussy. Depending on where you want to install this system, you may be required to have licensed operating engineers.

If you want backup power, why not consider a turbine that runs on natural gas? The advantages are nearly instant start up, no real maintenance when the system is not running and very little maintenance when it is running.

If you want to look at this type of turbine, look into the small jet engines used to power model airplanes. These groups of people have built turboprops for model aircraft so they have experience in gearing the extreme rotational speed of the turbine wheel down to efficient propeller speeds. You would need to gear down a steam turbine if you chose to go in that direction.

Steam engines are, in some ways, even more fussy, especially at start up since their cylinders (you will need 2 to have it self-starting) when cold, will condense the steam, requiring an open drain valve for a while. These are fairly high maintenance and are inefficient ways to covert energy.

Maybe you can buy an old ships-service turbine generator from the Navy. They are not super large (relatively speaking), are already built, have governors to keep the frequency constant and will run for thousands of hours with little maintenance. They do have to be warmed up before you can load them.

This is why the conversion of solar power into electricity via solar panels is popular. Very little maintenance and reliable.

If you really want to run a generator, you might look into Stirling engines while you are at it. Philips (Netherlands) was really big into power generation using this technology. They had a generator that had a coil moving back and forth in a tube that would generate electricity. IIRC, they could throw it into a campfire and get AC power.