I have been receiving emails that apparently come from Elon Musk Technology.

The emails discuss the Stirling engine as follows: “More than 180 years ago . . . Robert Stirling, a Scottish clergyman, invented something that shook the coal and energy industry to the ground.

“Stirling found a way to make an engine work literally on thin air using Tesla power. Unfortunately, his device became the first-ever suppressed ‘free energy’ generator. Only a few people had ever seen it. Now, for the first time, the ‘misplaced’ blueprints of the Stirling engine have been discovered and translated into ‘plain English’ so anyone can use them. Go here to see how Elon Musk incorporated this technology to make the remarkable Tesla battery packs – http://powergen.actionolyyyh.review/tryitnow.”

Another email is as follows: “Thanks to Elon Musk, Tesla has started producing free-energy generators. The technology is based on the blueprints from Nikola Tesla himself! This generator will save you 92% or more on your monthly power bills. Unlike expensive alternatives like solar panels, this Tesla generator is affordable to every American homeowner. Click here to start saving thousands every month on energy – http://starttoday.palaceending.accountant. The power companies want to stop Musk from producing these generators, so the above link will expire 01/13/2016.”

There are some things wrong here. Stirling patented his engine 40 years before Tesla was born. So, how “Stirling found a way to make an engine work literally on thin air using Tesla power” is open to serious question – apart from the fact that there is nothing that I know which is ‘Tesla power’. It is a fact that Stirling’s engine uses air as a heat-transfer medium, but this is not the source of its energy – that comes from a heat source external to the engine. Theoretically, you could use sunlight to power a Stirling engine but you would need about 5 m2 of collecting area, which is not very practical. However, there are a number of things that cause me to doubt the apparent genius of Musk. Did he invent PayPal? No, he did not – a firm called Confinity did and he bought it. Did his genius create the wealth of SpaceX, Tesla Motors and SolarCity? Well, a Los Angeles Times article revealed that SpaceX, Tesla Motors and SolarCity had together received an estimated $4.9-billion in government subsidies.

Getting back to the Stirling engine – is it a work of genius? Well, yes, in a way, it certainly is. The best part about it is that it can run on any heat source. And apart from the emissions from that heat source, there are no other emissions because the engine does not have internal combustion. It is very efficient as well – about as efficient as a diesel engine. It does take time to get going, so it is best suited to operating at constant speed or constant power.

As for the statement that “now, for the first time, the ‘misplaced’ blueprints of the Stirling engine have been discovered . . .” – it is pure eyewash. The Swedish Navy had three submarines fitted with Stirling engines in the late 1980s. However, one thing is certain: for generating power, unless the Stirling engine/generator/ alternator is connected to the grid, it is going to be very difficult to control the output such that the engine speed is constant at all electrical loads – with an internal combustion engine, you have very fine control over the engine power output. This is not the case with the Stirling engine – you have to control the power output by changing the heat source and by the nature of the device if you remove the heat source nothing happens for a bit which is also the case if you increase the heat source. It is a fact that the Stirling engine is more efficient than a steam engine, but I doubt that any power company would want a generation train which cannot respond quickly to rapid swings in power demand.

But the question remains: Why is this all, in the emails, associated with Musk? Clearly, all the claims made in the emails are near rubbish. It is a mystery.