Can Salt Store Heat Energy?

Sustainable energy is the provision of energy that meets the needs of the present without compromising the ability of future generations to meet their needs. Sustainable energy sources are most often regarded as including all renewable sources, such as plant matter, solar power, wind power, wave power, geothermal power and tidal power. It usually also includes technologies that improve energy efficiency (source: Wikipedia).

 In getting a sustainable energy, we question sometimes the availability of its sources, for example - solar power. How can we use solar when there is no sun? What do you do when the sun is not shining and what about during night?

The answer - store sunlight as heat energy for such a rainy day.

The salts known as one of our ingredients in food preparation help the facility light up the night. Salt, also known table salt or rock salt, is a mineral that is composed primarily of sodium chloride. Salt is one of the oldest, most ubiquitous food seasonings and salting is an important method of preserving food. Because most salts only melt at high temperatures (ie table salt which is a compound of high elements and you have to burn it at 1400 Fahrenheit or about 800 degrees Celsius) and do not turn to vapor until they get considerably hotter; they can be used to store a lot of the sun's energy as heat. Simply use the sunlight to heat up the salts and put those molten salts in proximity to water via a heat exchanger. Hot steam can then be made to turn turbines without losing too much of the original absorbed solar energy.

The salt, as we all know, is a mixture of sodium and potassium nitrate, otherwise used as fertilizers thus allowing enough of the sun's heat to be stored that the power plant can pump out electricity for nearly eight hours after the sun starts to set.

 "It's enough for 7.5 hours to produce energy with full capacity of 50 megawatts," says Sven Moormann, a spokesman for Solar Millennium AG - the German solar company that developed the Andasol plant. "The hours of production are nearly double [those of a solar-thermal] power plant without storage and we have the possibility to plan our electricity production." (source: Scientific American Article by David Biello).

There are a lot of ways that scientists tried to store the sun’s energy. Some tried batteries but it was too expensive. Water pumps or compressing air is possible but the resources are limited as well. Melting salts at temperatures above 435 degrees Fahrenheit (224 degrees Celsius), however, can deliver back as much as 93 percent of the energy, plus the salts are ubiquitous because of their application as fertilizers.

Thus renewable energy is achieved and a great alternative way in green energy.

This leads to scientists and researchers in quest for the utilization of salts instead of oil which is highly expensive in parabolic trough power plants, such as those that melt at lower temperatures and therefore would not freeze as readily during cold nights.

Combination of salts including calcium nitrate and lithium nitrate that melt below 212 degrees F (100 degrees C) are what other solar companies are looking in to and the benefits of these as well as its availability. Long-term research projects are also being done in the case of thermal storage technologies. In finding ways to store heat in sand or creating storage for salts – all for the goal of sustainability and at the same time save a lot of money.

The answer of whether salt can store heat energy is a big yes. The only thing that we need to discover is how can we store this and use it as a salt fertilizer on the ground. Who knows, that smallest ingredient in the kitchen may be the key in finding alternative ways for a better, sustainable energy in the future.