Solar thermal energy represents an alternative heat source for industry
It has already been used in various sectors with excellent results. It is therefore worthwhile to get to know the perspectives it offers. The following are some of the new applications and their benefits.
Applications of solar thermal energy in industry
The spectrum of applications of solar thermal energy in industry is very diverse. Its strength is its ability to provide heat that can be used in all kinds of low to medium temperature processes. This is a resource used in a variety of industries, where, however, up to now it has been the norm to use fossil fuels.
Solar thermal systems make it possible to achieve a wide range of temperatures with good energy efficiency. The food, textile, paper and chemical industries are good examples of industries that can benefit from this technology. Their production lines involve thermal processes in which this technology can be of interest: whether for drying a material or sterilisation processes in the food industry, a certain temperature must be achieved and maintained at a constant level.
The key to this energy lies in its potential. A high percentage of the used in the above-mentioned industries require temperature ranges below 100 ºC. However, higher temperatures of up to 200°C can also be achieved by concentrating the sun’s rays. Thus, processes such as drying, washing, sterilisation or uperisation could take advantage of this technology.
Some application examples
Many industrial organisations are already using solar thermal energy for a large part of their processes, with highly satisfactory results. The following are some of the success stories.
Some companies dedicated to the wine industry have already applied this technology. The flat roofs of warehouses can be used to install solar thermal systems to cover business needs such as heating and cooling water for wine-making processes, where it is essential to maintain suitable temperatures in order to achieve optimum results.
In addition, depending on the month of the year, the thermal needs may vary and it may be necessary to cool down (typically from May to September) or heat up (normally from October to December) the process involved, which are fermentation and wine stabilisation. The former requires a constant temperature of 21ºC, and the latter 15ºC. In wineries, the same storage place can be used for both processes, so the challenge is to create a system that achieves an acceptable yield. There are real examples where an area of 100m2 with a solar thermal installation achieves an annual production of 75 MWh, which can provide a significant part of the energy needed in the processes.
There are also real examples in sugar refining companies. In this industry, two processes involving heat are carried out: boiling and crystallisation. One technique for this process is to have three boilers fuelled by oil and/or natural gas. In addition, a steam turbine can be used to obtain steam at 125°C at 1 bar pressure for sugar processing.
In real applications, fossil fuel consumption may be concentrated on a single source or diversified by relying on more than one source (for example, natural gas and fuel oil). With the help of solar thermal technology, the use of these fuels can be reduced by means of a direct solar thermal system. With an area of 40×100 metres, it is possible to generate around 1,200 MWh of heat, which can be used to generate the required steam in accordance with the process requirements.
What are the benefits of this technology?
The economic advantages are the most interesting. Solar energy is abundantly available and can be easily exploited today. This saves a significant amount of money since avoids the need to buy fossil fuels on a recurrent basis. As the sun shines most of the year, solar thermal energy in southern Europe countries can be obtained efficiently. In the event of a surplus, it is possible to store it using salts, although this technology is not well-established and involves more complex installations.
On the other hand, the maintenance of this type of installation with solar thermal technology is also reduced, which decreases the associated structural costs and therefore shortens the amortisation period.
Energy efficiency is as well improved, as it is not necessary to consume any fuel. Whether for heating water or any other purpose, these systems achieve an extremely efficient use of the available energy. In fact, it allows up to a 50 % reduction in electricity use when using electric heaters – a leap in efficiency that should be taken into account.
It also reduces the dependence on the general electricity grid. A sufficiently large installation reduces the need for electricity if electric heaters are used, or the need for fossil fuels if heat is derived from these sources. In addition, the risks associated with fluctuations in the price of electricity or fuels are reduced.
A constant supply of thermal energy can be achieved, making it suitable for processes such as fermentation that require stable temperatures. In addition, it is a safe supply depending on the hours of sunshine, so that with good foresight, the dependence on maintenance of generators is reduced.
In addition to this, a competitive advantage is obtained: the energy used comes from a source, the sun, which will not run out in the near future and whose generation is free of charge. It only has to be captured and transformed to meet the needs of industry. Companies with solar thermal systems, by reducing their usual production costs, will be able to make new investments successfully.
Of course, carbon dioxide emissions are being reduced. The environmental benefits of these systems are well known, and this is one of them. It is important to curb emissions in order to slow down global warming, and any help in this regard is welcome.
The truth is that using renewable energy sources is becoming more and more common. Not only are they environmentally friendly, but they also allow significant cost savings. In addition, processes become more energy efficient by using less fuel.
In short, solar thermal energy offers very positive prospects in the field of industry, especially when it comes to achieving temperatures of around 100 ºC.
If you are interested in this type of technology, remember that at GoSafe with ESI we offer you a free consultancy so that you can learn how to guarantee the return on investment that you expect from such a project.