Solar Cooling Systems.....#SolarEngineering #Engineering #RubixStrategies #Entrepreneur


The usage of renewable energy resources is an important tool for energy security. Such resources are also responsible to stop the release of greenhouse gases which are increasing earth’s average temperature. Solar cooling systems are one of the wide range applications of solar energy. A latest research regarding solar cooling systems has been discussed here.

 Fig 1. Solar Reflectors

Fig 1. Solar Reflectors


The demand of solar cooling systems is increasing day by day for large buildings. Till now the solar cooling system being used, includes solar solid desiccant refrigeration, solar absorption refrigeration and solar adsorption refrigeration. All these systems are using flat collectors for solar radiation. Here a latest used technique is discussed which uses parabolic trough systems focusing light to receiver pipe directly. A heat storing fluid is passed through pipes that collect solar energy. The system can be used for power generation such as electricity as well as air conditioning.

 Fig 2 Solar Cooling System

Fig 2 Solar Cooling System


            Solar collector systems with parabolic trough were analyzed using Greenius simulation tool. The manufacturer provided the efficiency equation of collector


Incident angle modifier (IAM) tells relationship between position of sun and optical performance of collector. For current study the observed IAM is graphically represented here.

 iAM vs AOI

iAM vs AOI

            Experiment was done on two neighboring buildings of Greece. In building A number of installed ACs was 215 at 280kW of installed electrical power. On the other hand, building B consisted of 280 ACs with installed electrical power of 340kW. Buildings thermal power simulation was observed through ENERGY PLUS SOFTWARE TOOL.


            The advantage of solar cooling system becomes evident from this graph. Here the variation of cooling capacity in relation to DNI (direct normal irradiance) is shown.

 Cooling Capacity vs DNI

Cooling Capacity vs DNI

Next, is the depiction of changes in the output of thermal energy of solar collector field in relation to output cooling energy of chillers. Hence it is clearly evident that solar field can meet with the demands of chillers.


 Thermal Energy Output vs Cooling Energy

Thermal Energy Output vs Cooling Energy


·      World’s energy demand is expected to increase by 60% till 2030. On the other hand, nonrenewable energy resources are depleting day by day. Furthermore, excessive combustion of fossil fuels is imparting greenhouse effect on environment hence the average temperature of earth is increasing.

·      Since air conditioners are the highest electricity consuming electrical appliance, the replacement of ACs with SACs results in prospectus sustainable developments.

Financial Analysis


Normal AC Price: $650

Normal solar AC Price: $1,500

ACs in a building: 400

Electricity Consumption of Normal AC x 400 units = 4,680KW x 400 = 1,872 MW

Electricity Consumption of Solar AC x 400 units = 2,520KW x 400 = 1,008 MW

Electricity Saved x 400 units = 2,160KW x 400 = 864 MW

Saved (USD) x 400 units = $930 x 400 = $372,000

Capital of investment: Price of Solar AC x units = $1500 x 400 = $600,000

Return of investment: $600,000 / $372,000 ≈ 1 year 6 months

The above mentioned calculations indicate that the usage of SACs not only reduces the power consumption but the greenhouse gas release can also be avoided. Furthermore, the investment for SACs is also recovered after a relatively short period of time.



·      As indicated in all the statistical data the overall expense of solar ACs is less as compared to conventional AC system.

·       Investment would be remunerated soon.

·      There are less maintenance issues as compared to conventional methods.

·      No emission, no pollution.

·      Solar energy, a sustainable resource of energy. 

Reginald Swift