FALA | museum

The power plant at the time of its construction

The model shows the Fala hydro power plant at the time of its construction. A fish passage and a raft lock are also visible along the right bank of the Drava River. Until 1918, when the Fala Hydro Power Plant became operational, the water course was unhindered along the entire length of the Drava River, which is why a raft transport route was operated from areas rich in timber through the Podravje Region to the Danube Basin and further to the Black Sea. Before the upgrade of the railway, the Drava River was the only, and later on still the cheapest, transport route for timber and other goods. For this reason, the builders of the power plant were ordered in the concession contract to ensure that the power plant would allow rafts to pass. A raft lock and a fish passage were also constructed for this reason. At that time, up to twenty rafts carrying 90 to 100 cubic metres of timber travelled down the river daily between the spring and early autumn. The construction of the Fala power plant began in 1913, and on 6 May 1918, the first three generators of the Fala Hydro Power Plant were launched, followed by the fourth unit on 9 May and the fifth on 23 May. The power plant was originally designed to power the industrial basin of Central Styria with Graz as its centre, but the original plans were thwarted by the breakdown of the Austro-Hungarian Empire and new state borders. The plant produced its first kilowatt hours of electricity on the Drava River shortly before the end of the First World War to pave the way for all subsequent power plants on the river. The sixth generator was launched in 1925 and the seventh in 1931.

The power plant today

The model shows the Fala hydro power plant today. The installation of the eighth generator in the first sluice began in 1974 and it started operating three years later. An overhaul of the power plant, the construction of a new engine room and procedures to install the ninth and tenth generators in the raft lock and fish passage started in 1986. Generators one to three were decommissioned in 1990, followed by generators four and five a year later. Generators nine and ten started operating in the same year. What is today the oldest hydro power plant on the entire course of the Drava River, and the oldest operational large hydro power plant in Slovenia, operates with three generators, and following the overhaul it is remotely-operated as one of the most advanced hydro power plants in the country, producing around 260 GWh of electricity a year.

Turning chemical energy into electricity
– the galvanic cell

Galvanic cells form the most basic component of every battery, accumulator, and any other type of chemical energy storage system, whereby electrical energy is derived directly from chemical energy. The galvanic cell consists of two different metals which are immersed and dissolved in an electrolyte. Positive ions pass to the solution, while the metal remains negatively charged. Some of the ions return to the metal due to the electric field and the principle of diffusion. In a balanced state, a difference in potential emerges between the metal and the electrolyte. This potential difference depends on the metal and electrolyte used.
Luigi Galvani, (9 September 1737 – 4 December 1798) was an Italian physician and physicist who made a great discovery by accident. He was dissecting a frog using a metal scalpel charged with static electricity. He noticed that touching the nerve with scalpel, causing the dead frog’s legs to twitch. Galvani thus observed the effect of electricity on living organisms and is credited with the discovery of bioelectricity. His discoveries were used by Alessandro Volta in making the first battery, which was called the ‘voltaic pile’.

Turning heat into electricity
– the Peltier–Seebeck effect

The Seebeck effect describes the direct conversion of temperature differences to electricity. A metal rod generates voltage, given the temperature at the two ends of the rod is different. In practice, a thermocouple is most useful. A thermocouple consists of two different metal conductors joined in a loop. If the junctions have different temperatures, a current flows through the loop. Connecting two semiconductors has the same effect. The Peltier effect is the reverse of the Seebeck effect. The term describes the temperature change at an electrified junction of two different metals (or semiconductors). The junction heats at one end, and cools at the other, the latter phenomenon being especially useful in practice, as it can be used for cooling without use of mechanical components.

Thomas Johann Seebeck (1770 – 1831) was a German physicist, born in Reval – today known as Tallinn, the capital of Estonia. He received a medical degree, but preferred the exploration of physical phenomena. In 1821, he accidentally discovered that electric voltage is produced if the ends of a metallic rod have different temperatures. This is now called the Seebeck effect and is the foundation of thermometers based on thermocouples.

Jean Charles Athanase Peltier (1785 – 1845) je bil francoski fizik, ki se je preživljal predvsem s prodajo ur. Raziskoval je področja atmosferskih praznitev (strela), statične elektrike, hidrologije, barvnega spektra svetlobe, površinskih napetosti vode in vpliva višine na vrelišče. Najpomembnejše je njegovo delo na področju termoelektričnih pojavov. Leta 1834 je odkril, da enosmerni tok skozi spoj dveh kovin povzroči segrevanje na eni in hlajenje na drugi strani. Ta pojav so poimenovali Peltierjev pojav in se danes uporablja za hlajenje v prenosnih hladilnikih.

Turning light into electricity – the photovoltaic effect

Willoughby Smith discovered the photovoltaic properties of selenium in 1873. This marked the beginning of the era of solar cells made of solid materials. In the 1960s, photovoltaic cells using silicone and diffused semiconductor junctions were intensively developed for space technology. At the turn of the 21st century, the affordable price and characteristics of solar cells made it possible to use them for commercial purposes and electric power generation.

Alexandre-Edmond Becquerel (1820 – 1891) was a French physicist. Like many of his contemporaries, he studied electricity, magnetism, optics and other associated areas. His greatest achievement was the discovery of the photovoltaic effect, and the making of the first working solar cell.

Turning mechanical energy into electricity
– the electrostatic generator

The Wimshurst machine is an electrostatic generator which uses the principle of electrostatic influence for its operation, rather than friction (as did the earlier electrostatic generators by Wilhelm Holtz, August Toepler, J. Robert Voss and others). Two non-conductive discs set on a horizontal axis, separated by a narrow air gap, rotate in opposite directions. The discs are covered with metal plates which collect static electricity, which is then carried through brushes to capacitors. The capacitors are connected to a spark gap, through which the spark passes. James Wimshurst (1832 – 1903) was an English inventor and engineer, who worked in shipbuilding and maritime transport for the greater part of his working life. He developed several instruments to improve seafaring safety, such as a special vacuum pump, a device for indicating the ship’s stability, and methods for electrically connecting lighthouses to the mainland. The electrostatic generator, developed between 1880 and 1883, is without doubt his greatest invention; however, he never patented it. Despite the improvements made by other researchers later on, the generator is still named after its original creator, and is known as: the Wimshurst machine.

Turning mechanical energy into electricity
– the dynamo

A dynamo is an electrical generator that produces direct current through use of electromagnetic induction and a commutator. The first dynamo was built by Hippolyte Pixii in 1832. In this design, two coils with an iron core are fixed to a frame with a spinning magnet underneath, inducing alternating current in the coils. A commutator is installed on the same axis as the magnet, changing the direction of the current from the coils every half turn; this in turn creates a pulsating direct current at the output terminals. Hippolyte Pixii (1808–1835) was a lesser known inventor, who laid the foundations for further scientific research. As a maker of precision scientific instruments in Paris, he had the means and the knowledge to build complex devices. In 1832, he built one of the first alternating current electrical generators, based on the principle of magnetic induction discovered by Michael Faraday. He added a commutator to his generator, working with André-Marie Ampère to create the first pulsating direct current generator. His research was brought to an abrupt halt with his premature death at the age of 27. The invention of the commutator laid the foundation for the development of simple and versatile direct current generators – which we today know as ‘dynamos’.

Turning mechanical energy into electricity
– Faraday’s disc

The Faraday disc, also known as the homopolar generator, was the first generator to be based on inducing voltage in the magnetic field. A metal disc rotates in a magnetic field, which induces DC voltage that is harvested through two electrical contacts on the disc’s axis and rim. Due to its very inefficient basic structure, it is not used in practice, but upgraded versions are used to generate high currents of up to 2 MA, possible because of the low internal resistance present. The homopolar generator also formed the basis for developing modern-day DC and AC generators.
Michael Faraday (22 September 1791 – 25 August 1867) was an English scientist who studied electromagnetism and electrochemistry. His main discoveries were: Electromagnetic induction – based on the already discovered scientific laws and failed experiments of his colleagues, Faraday created the first device to transform mechanical energy into electricity using induced voltage – the homopolar generator. Diamagnetism – this describes the characteristic of certain materials to be repelled by a magnetic field. The Faraday cage – probably his most widely known and useful invention, it is still used today to shield from electric fields.

Electromagnetic transformers
– the resonant transformer

A resonant transformer based on LC circuits on the primary and secondary sides of an air-core transformer. The primary coil, consisting of only a few turns, is connected to a capacitor through the spark gap. The secondary coil consists of a very high number of turns. The capacitance for the secondary resonant circuit is provided by the parasitic capacitance of the coil and the toroid electrode. The first resonant generator was made by Henry Rowland in 1889 (and described in the journal The Electrician) to generate radio-frequency voltage. However, Rowlands did not patent his invention. Nikola Tesla patented a similar transformer two years later, in 1891. Tesla’s transformer applied the same principles as Rowland’s – but was able to generate much higher voltages. Even though the Tesla coil proved not to be a particularly useful invention, it was still very popular. This was partly due to its complicated principles of operation, and partly its audio-visual effects, of which Tesla made good use when presenting his inventions.

Henry Augustus Rowland (27 November 1848 – 16 April 1901) was one of the greatest inventors of his time. He worked as a Physics and Chemistry researcher in both Europe and the USA and is best known for his research on the effects of an electrically charged body in motion. Rowland also made a great contribution to Metrology by redefining the unit of electrical resistance, ohm (Ω), and the mechanical energy equivalent of heat.

Turning electricity into mechanical energy
– Tesla’s Egg of Columbus

Tesla’s Egg of Columbus was first presented at the Chicago World Fair in 1893. Despite having no practical value, the device drew much attention from the visitors. The upright egg, standing and spinning without any visible support, demonstrated the principles of the multiple-phase rotating magnetic field and the induction motor. The original Tesla egg involved a two-phase circuit. Four electromagnetic coils were wound around a toroidal iron core stator, and connected to the power source to create a rotating magnetic field. As voltages were induced and eddy currents created in the metallic egg, the egg started spinning in the same direction as the magnetic field.
Nikola Tesla (1856–1943) is probably the most famous inventor in the field of electrical engineering. He patented over 700 inventions, many of which still form the basis of electrical engineering today. He was born in Croatian Lika, which was then part of the Austrio-Hungarian Empire. He worked all over Europe and the USA, creating inventions spanning a variety of fields. The polyphase alternating system, for instance, can be used for transmitting considerable power over almost unlimited distances. Tesla’s polyphase induction motor is still the simplest and most versatile of electric motors. He also made several devices with no practical value, which, however, graphically demonstrated the principles of electrical engineering. These included the Tesla coil, and the Columbus Egg.

The switchroom at the time of construction

At the beginning of the operation of the power plant, the operation and control of its equipment was performed from the central control room, which was called the switchroom. It was equipped with the state-of-the-art protection and control equipment of the time. The switchroom was built with a great feel for aesthetics, and it is unfortunate that our predecessors failed to preserve it to be seen and appreciated by current and future generations.

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