Understanding Solar Cooling and Its Types

Are your refrigerator and air conditioner contributing majorly to your ever-increasing electricity bills? 

How about adopting a standalone system for cooling purposes that is predominantly non-toxic and environmentally sound? Well, we’re talking about a solar cooling system.

A solar cooling system not only brings down your electricity bills but also saves you from being an exploiter of conventional energy resources.

The hot blazing sun sets up a dire need for air-conditioning in our homes and workplaces. Why not utilise the abundant sunshine for your benefit to counter its heat effect? 

Well, using solar energy for the cooling effect may initially seem bewildering because we view the sun as a huge heat source.  

This blog covers all the details you must know before switching to solar cooling. 

What is the Solar Cooling Technique?

The solar cooling technique involves a system that converts the sunlight into cooling energy that can be used for air conditioning and refrigeration. 

The system collects solar power and uses it in a thermally-driven cooling process. 

This process decreases and controls the temperature for various purposes, such as conditioning air for a building or generating chilled water. 

The basic principle behind solar-driven refrigeration is much similar to regular refrigeration. Usually, a refrigerator produces cooling by evaporating a liquid refrigerant that absorbs heat and cools the surroundings. 

The major difference between solar cooling and conventional cooling is that the former uses solar thermal energy rather than electrical power. 

The idea is feasible because the sun’s energy is usually abundant during summers when there is high air-conditioning demand.  

Before moving on to the types of cooling techniques, it is important to understand the distinction between solar cooling and solar air-conditioning. 

Solar cooling reduces the temperature of a room/building/living space by removing the heat. 

Solar air-conditioning is the conditioning of a room/space concerning its temperature and humidity properties so that people feel comfortable inside the room.  

What are the Types of Solar Cooling Techniques?

There are four main types of solar-powered cooling techniques:

1. Vapour compression

In this type of refrigeration system, a circulating liquid refrigerant is used. But what does the liquid refrigerant do?

It acts as the medium that absorbs and removes heat from the area to be cooled. It dissipates that heat elsewhere. 

2. Sorption-Based Cooling (Absorption and Adsorption Chilling)

Although vapour compression is commonly used, the technology involves vibration and noise. 

Alternatively, sorption-based cooling devices rely on sorbents that hold the liquids to produce a cooling effect. Sorption cooling systems can have two different technologies: 

• Absorption cooling: In this type of cooling, the liquid is dissolved in the sorbent in one stage of the process and released in another stage. 
• Adsorption cooling: The liquid is bound to the surface of the sorbent in one stage of the process and released in the other. During winters, the adsorption device can act as a heat pump. 

3. Evaporative Cooling 

The technology depends on the phenomenon of evaporation for the cooling effect. The coldness is achieved by evaporating a liquid.

Evaporation consumes thermal energy and ultimately lowers the temperature of the evaporated substrate and the neighbouring material. 

Evaporative cooling devices are mostly used for air-conditioning. 

4. Solar Ejector Cooling

These solar-powered cooling systems rely on ejectors. The increasing and decreasing pressure in the machinery involves vaporisation and evaporation of the liquid, chilling the component and its surroundings. 

This type of cooling technique is used for both air conditioning and refrigeration. 

What are the Benefits of Solar-Powered Cooling?

Compared to conventional cooling systems, solar cooling offers huge electrical energy savings. The solar-driven adsorption chillers for off-grid buildings or homes are far better than using a diesel generator. 

Solar-powered cooling brings about a massive reduction in diesel fuel consumption. Additionally, it curtails carbon dioxide emissions and proves its loyalty to the environment. 

Furthermore, no environmentally harmful substance is used to produce the cooling effect as pure water or salt mixture is refrigerant.

Solar cooling systems require minimal maintenance. When coupled with occasional repair, they offer high efficiency.

What are the Limitations of Solar-Powered Cooling?

Solar-powered cooling has picked up the pace in various industrial settings and domestic cooling systems. However, they are often not economical. The high cost stands inefficient in translating the expectations of people. 

Moreover, a majority of people get intimidated by the initial investment cost involved in system components, ignoring the long-term operating cost benefits. 

What is the Scope of Solar Cooling in India? 

In March 2019, the Indian government launched the India Cooling Action Plan (ICAP), intending to reduce refrigerant consumption with a rise in cooling demand. They aim to enhance energy efficiency with better technologies. 

Presently, the cooling demand continues to rise, and according to the International Energy Agency (IEA), air conditioning and refrigeration are a 10% contributor to global CO2 emissions. 

solar-powered cooling solutions hold a strong potential but call for revamping the market. India is set to adopt renewable energy wherever possible, and it is estimated that solar cooling will soon pick up the pace. 

Conclusion 

Solar cooling systems are one of the most rewarding inventions that provide relief from extreme heat. The heat that creates discomfort is now responsible for creating a cooling effect. 

Solar-powered cooling also keeps the atmosphere healthy by reducing dependency on commercial grid systems. 

You can make your home self-sustaining and energy efficient. So, if your electricity bills are skyrocketing primarily due to home cooling, you must consider switching to solar cooling systems. 

FAQs

Q. What is solar-powered cooling technology?

Solar cooling technology involves devices and processes that utilise the sun’s energy for cooling. 

The solar collectors drive the cooling process by collecting solar energy and transforming it into thermal energy, which drives thermal cooling systems. 

Q. What are solar heating and solar-powered cooling? 

Solar heating is the use of sunlight to heat air or water in homes and buildings. It is of two types: passive and active. 

Similarly, solar-powered cooling uses the sunlight to produce a cooling effect in homes or workplaces. 

Q. What is passive solar cooling?

A passive solar cooling system reduces unwanted heat gain during the day by ensuring non-mechanical ventilation. It exchanges the warm interior air with the cooler exterior air.