posted 10 years ago
They look a little primitive. Not always a bad thing.
They use PTFE rings, which will require a very smooth bore in the cylinder to have any decent lifespan. Without running at elevated internal pressures, the output will be more like 100 watts rather than 1,000 watts.
Running pressurized is tricky to get done in real life.
There could be lifespan issues depending on exactly how hot the hot end gets.
The cold end looks air cooled, which has pros and cons. Water cooled will give a bigger temperature delta, and could be passive. Active cooling of either kind sucks up power if not done super efficiently.
Hey, they have actual stuff for sale, with actual running engines to look at and bigger than a toy. This already puts them head and shoulders above every other Sterling engine out there.