Tesla was no stranger to the necessity of proper timing for the adoption of a new technology:
The practical success of an idea, irrespective of its inherent merit, is dependent on the attitude of the contemporaries. If timely it is quickly adopted; if not, it is apt to fare like a sprout lured out of the ground by warm sunshine, only to be injured and retarded in its growth by the succeeding frost. (Click here for Tesla’s quotes).
Nikola Tesla is well known for inventing the AC motor, despite the fact that it was viewed as technically impossible by Edison. He also invented wireless communication. Both of these technologies became commercial realities almost immediately after their reduction to practice. Less well known is that Nikola Tesla was a big proponent of sustainable energy. However, the above quote could not be more applicable as his ideas and inventions in this burgeoning field fell by the wayside. Society simply wasn’t ready for them at the time.
In his body of work, he describes a machine that can gather heat from the ambient air. His “Self-acting Engine” could run indefinitely from the solar energy stored in the air. He patented the technology in 1901 under U.S. Patent No. 685,957.
The patent discloses a device that comprises a condenser (C), an insulated plate or conducting-body which is exposed to the rays (P), and another plate or conductor which is grounded (P’), all being joined in series. Terminals (T T‘) of the condenser are also connected to a circuit which includes a device (R) to be operated and a circuit-controlling device (d).
The following excerpt from his patent explains how the technology works:
The sun, as well as other sources of radiant energy, throws off minute particles of matter positively electrified, which, impinging upon the plate P, communicate continuously an electrical charge to the same. The opposite terminal of the condenser being connected to the ground, which may be considered as a vast reservoir of negative electricity, a feeble current flows continuously into the condenser, and inasmuch as these supposed particles are of an inconceivably small radius or curvature, and consequently charged to a relatively very high potential, this charging of the condenser may continue, as I have actually observed, almost indefinitely, even to the point of rupturing the dielectric. If the device d be of such character that it will operate to close the circuit in which it is included when the potential in the condenser has reached a certain magnitude, the accumulated charge will pass through the circuit, which also includes the receiver R, and operate the latter.
Tesla also advocated for geothermal energy. He stated that “[a]nother way of getting motive power…would be to utilize the heat contained in the earth…for driving an engine”. (Nikola Tesla, Century Magazine, June 1900, The Problem of Increasing Human Energy, With Special Reference to the Harnessing of the Sun’s Energy). Wind energy is also mentioned in the article, but he mentions that the wind is intermittent and so the energy captured would need to be efficiently stored between generation in order for the technology to be viable.
However, oil was abundant in the 1930s and could be extracted at low cost. Coal was also a cheap energy source. As a result, there was no impetus for investigating non-fossil energy sources. Also, sustainability was not in the forefront of people’s minds as it is today. He died without any of his inventions in renewable energy being commercialized.
Nonetheless, Nikola Tesla’s contributions to modern science cannot be ignored. His pioneering inventions in the field of electronics are described in over 200 patents. Most of these patents are available to the interested reader on public databases.