Solar furnaces not only produce heat, but generate electricity too: Here’s how
In your environmental science classes, you might have learned that solar energy is the most widely used type of renewable energy. You might be familiar with several low-cost items, such as solar cookers, solar water pasteurizers, solar-powered grills and solar crematoriums, that convert solar energy into electricity. Do you ever wonder about the science underlying these incredible pieces of equipment? Let us introduce you to a solar furnace. It is a heating principle that works on the simple idea of reflecting the sun's rays and concentrating them on to a point in order to raise the temperature. This heat may be converted to steam, which is utilized to generate energy in a power plant!
Félix Trombe, a French professor, created the first modern solar furnace, the Mont-Louis Solar Furnace, in 1949. The world's largest solar furnace is the Odeillo Solar Furnace, which is also located in France. Let us learn more about how solar furnaces work and the largest solar furnace ever made!
How does a solar furnace work?
The functioning of a solar furnace is quite simple. It involves using a simple mirror and a parabolic (concave) mirror. The plain mirror, referred to as a heliostat, is angled to focus a parallel beam of the sun's rays onto the parabolic mirror. The parabolic mirror concentrates the light beam at the focal point of the furnace. The precision with which the mirrors are directed at one place directly affects the energy produced and the efficiency of the solar furnace. If you increase the number of mirrors, you can get energy and heat levels that are high enough to cook meals and boil water.
How does a solar furnace generate electricity?
There is more to solar furnaces than generating heat, it can generate electricity as well! How? The procedure involves pumping molten salt into the furnace to increase its temperature. First, hot, molten salt is passed through the furnace where its temperature increases up to 300-600 degrees Celsius. The molten salt is then transported to a storage tank. From there, it passes through a steam generator, which heats the water. The resultant steam that is produced due to the heat enters a steam turbine. What happens to the salt that is left behind? The now cold molten salt is returned to the storage tank. The steam that enters the steam turbine causes it to rotate as it passes between blades. A condenser then condenses this steam. The generator produces electricity, while the condensed steam is returned to the steam generator to repeat the cycle.
The largest solar furnace of the world
The Odeillo solar furnace is in the southern French town of Fort-Romeu-Odeillo-Via holds the world record for being the largest solar furnace of the world. It is 54 metres high and 48 metres wide. When was it created? The furnace was constructed between 1962 and 1968 and started operating from 1970.
What is fascinating is that the furnace features 63 heliostats and 180 single mirror panes. The dimensions of each heliostat are 6.5 metres by 7 metres. Combined, it forms a large concave mirror with an area of 2,835 square metres. This mirror reflects sunlight onto a small focus point, which reaches temperatures of more than 3,000 degrees Celsius within the furnace! What purpose does this massive solar furnace serve? It is employed for a variety of tasks, including the melting of steel, production of electricity through a steam turbine, production of hydrogen fuel, testing of materials for spacecraft and high-temperature metallurgical (study of metals) studies.