Thanks for your thoughts.
I am not set on hot-air - read my post to David.
re:"I see hot air (Stirling isn’t technically hot air) or Stirling as inefficient due to all the things required to build a setup, and then further to get to the correct rpm to run a generator head because the rpm of the engine likely won’t come out at the 1800 or 3600 needed for generation."
"Stirling patented a second hot air engine, together with his brother James, in 1827. They inverted the design so that the hot ends of the displacers were underneath the machinery and they added a compressed air pump so the air within could be increased in pressure to around 20 atmospheres. It is stated by Chambers to have been unsuccessful, owing to mechanical defects and to “the unforeseen accumulation of heat, not fully extracted by the sieves or sin ill passages in the cool part of the regenerator, of which the external surface was not sufficiently large to throw off the unrecovered heat when the engine was working with highly compressed air.”
"The term "hot air engine" specifically excludes any engine performing a thermodynamic cycle in which the working fluid undergoes a phase transition, such as the Rankine cycle. Also excluded are conventional internal combustion engines, in which heat is added to the working fluid by combustion of fuel within the working cylinder. Continuous combustion types, such as George Brayton's Ready Motor and the related gas turbine, could be seen as borderline cases. "
Around that time, Philips was seeking to expand sales of its radios into parts of the world where grid electricity and batteries were not consistently available. Philips' management decided that offering a low-power portable generator would facilitate such sales and asked a group of engineers at the company's research lab in Eindhoven to evaluate alternative ways of achieving this aim. After a systematic comparison of various prime movers, the team decided to go forward with the Stirling engine, citing its quiet operation (both audibly and in terms of radio interference) and ability to run on a variety of heat sources (common lamp oil – "cheap and available everywhere" – was favored). They were also aware that, unlike steam and internal combustion engines, virtually no serious development work had been carried out on the Stirling engine for many years and asserted that modern materials and know-how should enable great improvements.
By 1951, the 180/200 W generator set designated MP1002CA (known as the "Bungalow set") was ready for production and an initial batch of 250 was planned, but soon it became clear that they could not be made at a competitive price. Additionally, the advent of transistor radios and their much lower power requirements meant that the original rationale for the set was disappearing. Approximately 150 of these sets were eventually produced.
I know they use Sterlings in CSP (concentrated solar power) where they have a field of parabolic dishes (about 15 ft is diameter) and generate electricity.
re wood gamification and electric starters - see reply to David
Personally I think Ecrisson's may be better.