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What is Active Solar Energy?

  • Ritesh Pathak
  • Mar 19, 2021
What is Active Solar Energy? title banner

Have you ever thought about how good it would be if we could do everything using sunlight? From cooking food through sunlight, warming our homes in winters, to keeping our houses cool in summers? 


Solar energy is probably the most abundant source of energy available on the earth. We can define solar energy as the radiations coming from the sun that are utilized to generate heat and electricity.


Since solar energy is a renewable source of energy, we cannot run out of it. This gives us the freedom to experiment and find the most effective and efficient way to use it. 


Active solar energy is one such way that helps us make the most out of the abundant sunlight we are getting on a daily basis. For cold climates, active solar energy is a great option to keep your homes warm. 


With active solar energy, we can do a lot of things. So, let’s explore everything about active solar energy. 


There are two types of solar energy that are classified based on how sunlight is converted into useful energy: active solar energy and passive solar energy



What is Active Solar Energy


Active solar energy refers to the solar energy that we capture and store for future use. In other words, active solar energy is the energy from the sun that is increased by the use of electricity or other mechanical equipment. It is a sustainable use of sunlight. 


To store solar energy for future use requires a setup of mechanical and electrical equipment like fans, water pumps, etc. It is a cost-effective way to take advantage of solar energy.



Types of Active Solar Energy


Based on its applications, active solar energy is classified into three categories: 



Active Solar Space Heating


Active solar space heating uses mechanical equipment like fans, pumps, blowers, and ducts to collect, store, and distribute heat throughout the air/space inside our homes. 


These active solar systems can be either liquid-based or air-based. The liquid-based systems use large water tanks to store and distribute the heat. These systems make use of pumps, radiant slabs, central forced air, or hot-water baseboards. 


In air-based systems, we have thermal mass or rock bins to hold the heat as well as ducts & blowers to distribute it.  



Active Solar Water Heating


Active solar water heating systems are used to heat the water in homes. It uses pumps to circulate the water or heat-transfer fluid through the system. 


There are two types of active solar water heating systems: indirect and direct. 


The indirect system has a fluid that is an anti-freezing mixture. This fluid is first heated in the collector and then passed into the storage tank where a heat-exchanger transfers the heat from fluid to the household water. 


While in the direct systems the household water is directly heated in the solar collectors. Once the water is heated it is pumped into storage tanks which further pipes into faucets for use.  



Active Solar Pool Heating


Active solar pool heating, as the name suggests, is used to heat the water for your pool. You may wonder, isn’t it the same as active solar water heating? 


In the active solar pool heating, the water from the pool is passed through solar collectors and once it is heated it is piped back into the pool area. This eliminates the need for storage tanks. 



Difference between Active and Passive Solar Energy


As mentioned above, solar energy is divided into two categories based on how sunlight is being converted and used. The two types differ in a few ways which we have listed below.  


  • Active solar energy makes use of electrical and mechanical equipment.  On the other hand, passive solar energy is the power from the sun that requires no other energy or mechanical system. We can call it the direct and live use of sunlight to generate electricity or heat. 


  • Active solar uses special boxes called solar collectors to collect sunlight and convert it into heat while passive solar uses the design of the home to capture sunlight. 


  • We can also say that passive solar energy is a more natural form of solar energy while active solar energy is a tweaked form of solar energy. 


  • Active solar energy is more beneficial in the way that it does not require you to change the orientation of your house while to use passive solar energy, you must have your house in a proper orientation.  


  • Applications of active solar heating include active solar space heating, active space water heating, active solar pool heating and the applications of passive solar energy are passive heating, passive cooling, and daylighting. 



Working of Active Solar systems


Active solar systems use solar energy to heat a fluid that can either be liquid or air and then transfer the heat directly to a storage system for later use. The active solar systems work on the basic principles of thermodynamics.

The image shows how an active solar system uses solar energy to heat water.

Working of Active Solar System

These systems are also backed up by an auxiliary system, in case the solar system cannot provide adequate space heating. 


Liquid-based active solar systems are more often used when a storage system is included. These systems are well suited for radiant heating systems, boilers with hot water radiators, and even absorption heat pumps and coolers.


Solar energy is captured through solar collectors in the active solar systems. Once the fluid gets heated it is passed into the storage tanks for use later. 


When required, the fluid is run through a heat exchanger. This is either used to heat the space in the house or to warm the water in use. 



Components of Active Solar System


As an active solar system involves the collection, storage, and distribution of energy, there are three essential components: 


Solar Energy Collection: This is done with the help of a solar collector, commonly a  flat-plate collector, which is simply a glass-covered insulated box. The box contains black absorber plates that absorb solar energy and convert it into heat. 


Solar Energy Storage: Storage can be done with water tanks or thermal mass for liquid-based systems. For air-based systems, we can use rock bins to hold the heated air. 


Solar Energy Distribution: For distribution in liquid-based system pumps, radiant slabs, central forced air, or hot-water baseboards can be used; and for air-based systems, fans and ducts can be used to distribute the heated air.  



Why use Active Solar Energy?


Having an active solar system installed in your home can prove beneficial for you. Since solar energy is probably the cleanest energy available, why not use it to the fullest. 


Here are some prime benefits of active solar energy you should know about. 


  • Active solar energy is the best alternative in cold climate conditions with good solar resources available. It can displace the more expensive heating fuels, such as electricity, propane, and oil.


  • Some states offer sales tax exemptions, income tax credits or deductions, and property tax exemptions or deductions for solar energy systems. For example, if you live in Great Britain you can also receive payments for the surplus energy under the   scheme. 


  • You can get an active solar system installed in your home regardless of the orientation or the design. 


  • Solar collectors come with a warranty of more than ten years. This means it can last a decade 


  • The heat energy produced can be used for several purposes. Ultimately it can reduce our electricity bills. 


  • A solar heating system will also affect the pollution levels and greenhouse gases that result from the use of fossil fuels for heating or generating electricity.



Points to remember


There are some notable points to remember about active solar energy. 


  • Active solar energy is a better option as it allows us to use solar energy according to our time of need. 


  • Active solar heating systems are most cost-efficient in cold climate conditions. The reason is that in active solar systems, heat is stored and mechanically or electrically supplied to the grid or house to meet the energy demand. 


  • Active solar energy is obtained in two mediums: air and water or anti-freezing solutions placed in a container. Both these are heated with the help of sunlight. 


  • The heat trapped in the containers is passed further using fans and pumps to either run a device directly or store it in a generator to supply it locally. 


  •  While using active solar energy few things that are to be considered include the selection of mode i.e. air or water, location, system design whether big or moderate, and whether it is being used for full house use or partial use. 


  • One more thing that determines if an active solar system would work or not is the presence of a backup system in parallel. As sunlight is not always there a backup energy system ensures a constant and continuous supply of heat or electricity.


Recommended Read: Can electric vehicles save the overall environment?


Active solar energy is a great option to consider if we want no further rise in the temperature of the earth. Being economical and environment-friendly it can even help lower the temperature. 

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  • solarproducts854f1023b24c6a40e4

    Jul 22, 2023

    Your blog post resonated with me on a deep level. It's clear that you have a true passion for the subject." https://www.jaysis.ai/