Solar thermal energy takes advantage of the sun’s energy to obtain heat. Industry and in the residential and commercial sectors can use this technology.
Solar thermal energy is defined as low, medium, or high-temperature collectors (CSP energy). Typically, residential collectors work at low temperatures.
Energy storage capacity plays a vital role in compensating for fluctuations in energy production and consumption.
Energy storage technology is used and the up and downregulation of power stations to balance an electricity network.
Many solar thermal applications take advantage of this renewable energy taking advantage of the thermal sun’s energy.
1. Electricity generation
Concentrated solar power facilities are a kind of thermal power plant to generate electricity. Then concentrated solar power systems use solar thermal collectors to obtain heat.
These plants use fuel to generate steam at a very high temperature. The generated steam drives a steam turbine that is connected to an electrical generator by a shaft. They convert solar radiation into thermal energy, later into mechanical energy, and finally, into electrical power.
To have a sufficiently large temperature, they use many solar concentrators such as parabolic troughs and solar furnaces. The solar radiation is concentrated on a power tower where the thermal energy generates steam.
It is a system to generate electricity as an alternative to photovoltaic solar energy.
2. Swimming Pool Heating
Heating water to levels below boiling allows the use of black collectors for thermal absorption of solar radiation.
Heating a swimming pool can consume a big amount of energy. Plus, in some countries, it is not allowed to warm using non-renewable energies. Energy-efficient pool heaters can improve your swimming pool's heating and energy efficiency.
3. Solar Underfloor Heating
Solar Underfloor Heating is a kind of solar heating. It consists of an electrical resistance glued to a mesh placed under the tiles or other pavement types on the floor.
Solar thermal systems can provide power underfloor heating by heating water.
An advantage of this system is that the fluid must not have such a high temperature by distributing the temperature more uniformly. This feature makes solar thermal energy an almost perfect technology for heating that water.
The system for heating the heating circuit is the same as in the case of domestic hot water. The same solar collectors installed outside the house allow us to obtain the maximum use of energy.
Solar panels convert solar energy into thermal energy, which can be heat transfer fluid. Transfer fluid circulates through the heating circuit. It will allow saving energy and reducing your electrical bills using solar thermal power.
If the solar system cannot provide adequate space heating, an auxiliary or back-up system provides the additional heat.
4. Production of domestic hot water (DHW)
Domestic hot water (DHW) is the water that we use at home. For this proposal, we do not need this water to be excessively hot. Thus, we can use flat plate collectors that can be quickly heated on the roof and heat exchangers. Due to their shape, glass tubes can better resist the ambient air pressure.
The time to heat a liter of water is longer than the time it takes to consume. Thus, we cannot heat at the same time it is needed. To solve this problem, we can use energy storage systems.
In small houses, it is pervasive to see solar collectors. The function of these solar panels is to heat sanitary hot water for domestic use or heating. They are generally support systems, but they allow considerable financial savings.
What is a solar collector?
A solar collector is an exchanger that converts direct and diffuse sunlight into heat.
The heated water in the pipes is pumped, and the heat from it is stored in an insulated storage vessel: the boiler.
When the pipes’ temperature is higher than in the boiler, a control unit turns on the pump.
As a result, the solar collector is cooled by the boiler’s cold water. And then, the boiler is heated by the hot water from the solar collectors. After some time, when the solar collector and the water heater have almost the same temperature, the control unit switches off the pump.
5. Solar thermal energy for cooling, refrigeration, and air conditioning
Getting cold from heat is a paradox, but it is possible thanks to the absorption cooling technique.
The technology used in these systems, absorption cooling, is based on absorbing heat from specific pairs of substances. Its operation is based on the physical-chemical reactions between a refrigerant and an absorbent. It is activated by thermal energy -which in the case of solar energy is hot water.
The operation of any absorption refrigeration machine is based on three elementary physical phenomena:
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When a fluid evaporates, it absorbs heat, and when it condenses, it gives up heat.
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The boiling temperature of a liquid varies as a function of pressure; as the pressure drops, the boiling temperature drops.
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There are pairs of chemicals that have a particular affinity when it comes to dissolving each other.
6. Solar energy in powering agriculture
For agricultural production and processing, solar energy is a crucial energy source, particularly drying, heating, and cooling.
Up to 70 percent of agricultural products spoil during the traditional open-air drying process, especially in tropical and subtropical regions.
Cooling and refrigeration are essential in agricultural processes. It is typically a very energy-intensive process. Solar-powered cooling presents a crucial clean energy opportunity, particularly in rural areas without access to the national grid and other processors.
7. Solar heat for industrial processes
Solar thermal systems (STS) can fulfill a vast amount of heat demand in industrial processes.
In developed economies, solar thermal can provide technically about half of this energy consumption by supplying hot water and steam.
In some industries, solar thermal energy can process heat to provide hot air and hot water. Textile, brick, and food processing industries are examples of industries using solar thermal.
8. Efficient thermal desalination with solar energy
Currently, there are many desalination solar projects working. This solution allows you to reduce operating costs and reduce greenhouse gas emissions.
These systems could serve arid coastal areas. It is oriented to populations outside the conventional distribution network. This system seeks to provide an efficient and low-cost source of water.
The system uses multiple layers of flat solar evaporators and condensers, aligned in a vertical array and covered with transparent insulation.
