Using heat as an energy source to generate electricity quietly seems like a more natural type of power system. The iconic inventor Nikola Tesla patented an unusual machine to do that, and once declared it to be his favorite invention. However, Tesla’s era lacked the strong materials we now have for super-high speed rotation of metal discs. Now it can be built.
His “bladeless turbine” quietly converts heat into speed of rotation. Water or steam comes in at the periphery of parallel discs and spirals into the center. If it builds up a fast enough speed, what is called a boundary layer effect (instead of steam causing friction, the steam makes the discs spin via adhesion and viscosity) will cause a turning force. That torque allows for generating electricity.
At the 2023 Energy Science and Technology Conference in Washington state, Jeremiah Ferwerda demonstrated a prototype of a six-inch diameter Tesla Turbine. It had already been tested, without an electrical load, as turning at 42,000 RPM (revolutions per minute.) With its rotor turning that fast, the periphery of its discs would have been rotating at a speed faster than Mach 1. The demonstration at the conference in July 2023 included powering a bank of light bulbs.
The goal for Jeremiah and conference organizer Aaron Murakami is to develop this into a viable powerplant.
Jeremiah cited multiple uses for Tesla’s turbine in the near future when it will be commercially available. For instance, if you have a wood-burning stove, in the wintertime you could charge your batteries by using the heat from the wood stove.
Or you can make a DIY “sand battery” as a way to store heat for generating electricity. A pipe going through the solar-heated sand then loops through a low-pressure boiler. Its output goes through a Tesla bladeless turbine and then to a condenser that cycles the cooled liquid back to the beginning of the cycle.
Every year the experimenters’ prototypes become more compact, more efficient—putting out more power.
The demonstration at the conference avoided pushing the turbine to the limit, so that the team could get through the presentation without fear of damaging the turbine.
A preview video says “After the conference, at 260 F (degrees Fahrenheit,) and it produced 1,300 watts.”
An expert in electrical science, Eric Dollard, supervised the test to verify its power output. Aaron Murakami added that “Nobody else in the world showing their Tesla Turbine experiments is showing this much real power output!” The test is briefly shown in the preview video on the eMediaPress website.