Solar Thermal for DHW (Domestic Hot Water)
Solar thermal energy consists in converting solar radiation into heat, which in turn is transfered to a fluid (air or water), by simple conduction using devices called Solar Collectors.
According to the temperature achieved, solar thermal systems may be classified in:
- Low Temperature Systems: Heat water up to 70°C by means of flat plate collectors. They are normally used for domestic DHW and heating applications.
- Mid-Temperature Systems: Water may reach up to 300°C using concentrated solar heat. Commonly applied in industrial processes and power generation.
- High Temperature Systems: By means of CSP (Concentrated Solar Power) systems, temperatures up to 350°C may be achieved. Applications include power generation.
Advantages of Solar Thermal:
- Houses and buildings may achieve between 50% and 80% savings
- The investment is payed-back by energy savings
- Currently, solar thermal projects may have payback times of 2 to 6 years
- System lifetime of 30 years
- O&M costs are reduced with technological developments
- Domestic Hot Water: DHW is the supply of hot water for daily use, that enables people to enjoy a better quality of life. Solar thermal systems generate this water sustainably, reducing the dependency on boilers or heaters
- Heating: Besides solar thermal energy being used for DHW production, energy may be used for space warming, by means of radiators or radiating floors (thermal efficiency is higher and the operating temperature is lower than conventional radiators, around 30-40°C
- Pool Water Heating: Swimming pools can be climatized, wether they are indoor or outdoors, using solar energy. Enormous savings in energy may be achieved by heating pools with solar thermal, due to the large volume of water to be heated
- Solar Cooling: Use of absorbtion chillers for the production of chilled water, with residential or industrial applications
- Preheating in industrial applications: In processes where hot water or steam is required, preheating using solar thermal reduces operation costs associated with fuel expenditure due to water heating
- Drying: For drying processes (agriculture or industry) of seeds, tobbaco, or other bioproducts. Warm air is generated and circulated in drying chambers, which is then put in direct contact with the product for humidity removal