Now there are some other ideas that I think a quasiturbine might play a role: I have the idea of making a "hybrid" vehicle but one that uses pressurized air instead of electricity for the "hybrid" part. Not only can I have the fuel burning engine be a quasiturbine type but I can also have quasiturbine-type air compressors and quasiturbine-type pneumatic motors in the wheels. One of the problems I had with putting pneumatic motors directly on the wheels is the low torque at low RPM for some motor types and upper RPM limitations for the the high-torque-at-low-RPM types. The Quasiturbine seems to be good at both ends of the RPM scale. For air storage tanks, I was thinking of turning the frame into a network of air tanks (unibody construction is mostly hollow). Turbo-chargers are just compressors on the air intake and pneumatic motors on the exhaust in order to increase the working pressure of the engine (as well, some have heat exchangers between the exhaust and air intake) The use of a quasiturbine type of compressors and pneumatic motors in the turbocharger might be an improvement (not sure if it is an improvement over traditional turbines in that application though).
Not for vehicles, but for solar energy gathering, pumps and turbines are often used and Quasiturbines might prove to be improvements.
"Wet" steam (with droplets of water) will destroy a turbine so the less efficient and noisy piston type steam engines are usually used. A quasiturbine might prove to be the best option for a small scale solar-generated steam to electricity system. I might want to include the storage possibility of using large underground air tanks and using compressors and pneumatic motors like in my hybrid car idea but one potential downside is the need for lubrication for some types of pneumatic motors but Quasiterbines can be designed for oil-free operation.
If quasiturbine-type stirling engines are as much an improvement as suggested, then using refrigerants instead of steam can be used and solar energy can be gathered with solar panels with operating temperatures being very low to gather energy earlier in the day and on very cold days and possibly with flat-panel solar collectors instead of focusing ones that work well on cloudy days or even just from light reflected off the cloud cover (focusing ones only work in direct sunlight).