Up till now, you knew that solar panels are used to convert solar energy into electricity. But using solar energy with other devices for heating purposes is also possible. Did you know that? How can you use solar energy without solar cells? This you will find out in active solar heating vs passive solar heating. Also, how is active solar energy different from solar energy? You must also be wondering how does active solar energy work?
What is Active Solar Energy System?
The term active solar energy refers to thermal heating systems. Solar energy is a crucial renewable energy resource along with being a source of heat and light to all living beings. The term active solar energy system refers to the type of system used. Solar thermal installation plants using electronics, moving parts, and electronic controls are considered a part of active solar energy systems. It is used for heating as well as for electricity generation for homes and communities. With this, you have learned what is active solar energy system.
How Does Active Solar Energy Work?
Photovoltaic cells are the basis of the working of active solar energy. They carry out the task of collecting solar energy received from the sun in form of photons. However, active solar energy has two basic designs for working: thermal system and photovoltaic system.
1. Working of Thermal System
This system works by collecting sunlight and concentrating it to produce high-temperature heat for generating electricity. Two components of a thermal system are receivers and reflectors in form of mirrors that capture and focus sunlight falling on them. During the daytime, the solar energy storage system collects solar energy and uses it after sunset.
Heat transfer liquid is heated and circulated in receiver containers, thus producing steam. Mechanical energy from steam works within turbines and powers up a generator to produce electricity.
2. Working of Photovoltaic System
Silicon-made solar panels are used to absorb solar energy and create an electric field. Solar panels are layered with other materials that enable each upper and lower side to have a positive or negative charge. Phosphorus used in the top layer makes it negatively charged and boron used in the bottom layer gives it a positive charge. Energy generated by freely moving electrons is transmitted to wires by the metal conductive plates on their side. This energy flowing from solar cells into wires is converted into electricity and thus, used for heating and other purposes. After this, let’s see What are three active solar types.
Also Read: 3 Leading Types Of Solar PV System
What are Three Active Solar Types?
Based on their applications, what are three active solar types: are mentioned below.
1. Active Solar Pool Heating
Through this system, swimming pool water is heated with solar energy. During the process, water from the pool is passed through solar collectors to be heated. Once the water reaches the optimum temperature, it is piped back into the pool. With this process, there is no requirement for a storage tank.
2. Active Solar Space Heating
Mechanical equipment like pumps, blowers, fans, and ducts are used to collect, store, and distribute heat throughout the space or air inside the house. Active solar space heating can be air-based or liquid-based. After learning how does active solar energy work it is interesting to know about other aspects too.
- Air-based systems use rock bins or thermal mass for holding heat. To distribute, the same blowers and ducts are used.
- Liquid-based systems use central forced air, radiant slabs, hot-water baseboards, or pumps. Large storage tanks are used for storing and distributing heat. It is suitable for radiant heating systems, absorption heating pumps, and boilers with hot water radiators.
3. Active Solar Water Heating
This is applicable for household uses in which pumps circulate water or heat-transfer fluid throughout the system. Indirect and direct are two types of active solar water heating systems.
Also See: 5 Methods of Solar Energy Harvesting
What are Components of Active Solar System? What is the Working of Active Solar Heating System?
The main components of active solar system or active solar heating system are as follows:
- Collector controls
- Heat storage controls
- Distribution controls
Now, the working of active solar heating system includes the use of the above-mentioned devices to capture solar radiation and convert it into thermal energy. It also uses flat-plate collectors and radiant panels to carry out its work.
1. Flat-plate collectors: It is a type of solar thermal collector used for collecting and storing heat from the sun. It is a dark-colored absorbing plate placed in an insulated box. Sunlight absorbed by the plate heats up fluid running through it.
2. Radiant Panels: They are also a type of thermal collector that absorbs sunlight and converts it into heat. This is transferred to the environment through radiation. It is useful in warming floors or walls of a room, and it is of three types namely, ceiling, floor, and wall.
3. Controls: Switches, motors, and sensors are used for operating the system. Controls help in avoiding extremely high or freezing temperatures. For monitoring temperature in different parts of the system other controls are used that determines its operational levels. Sophisticated systems with microprocessors are used to control and optimize heat transfer along with delivery to storage tanks and different parts of a house. Getting to know about components after learning how does active solar energy work is useful though.
- Differential thermostat: It is considered the heart of a control system, and it measures temperature differences between storage units and collectors. In case the collector gets warmer than the storage units (difference between 10° to 20° Fahrenheit), the thermostat turns on the fan or pump. This air or water through the collector will heat the house or storage medium.
Why Use Active Solar Energy?
Using active solar energy is a good catch because it is a one-time investment with lifelong returns. Yes, the amount you put into installing the system will be retrieved within 5 years or even less in the form of savings on utility bills. Installation costs may vary, but it has an overall lifespan of about 20 years or more under suitable conditions.
Also, another reason why we use active solar energy is that it reduces carbon footprint, and you play your role in reducing air pollution and emission of greenhouse gases. This should have explained why use active solar energy.
Also See: Solar Charge Controller Settings
What is Active Solar Heating Vs Passive Solar Heating?
To understand things better here is a list of pros and cons of active solar heating vs passive solar heating.
1. Active Solar Heating
a) Pros
- Electricity bills are reduced with less electricity being consumed for heating purposes.
- In the case of conversion rate, an active heating system is more effective.
- It can be easily installed in any location.
- It is an environmentally friendly heating option through which carbon footprint is reduced.
- Power generated for heating purposes can also be converted into electricity for running household appliances.
b) Cons
- Installation is expensive as lots of equipment like solar panels, heat exchangers, and distributors need to be installed.
- Additionally, regular maintenance requires charges.
- A lot of space is required for installing a number of devices.
- Another power source is required for powering fans and pumps.
- The amount of power generated is unpredictable and can be hindered by solar panel malfunctioning.
2. Passive Solar Heating
a) Pros
- Except for building maintenance, no additional maintenance is required.
- It helps reduce utility bills and is yet another way how does active solar energy work to save expenses.
- No additional collector is required because floors and walls act as heat collectors.
- No extra power source is needed
- Reduces carbon footprint and is environment-friendly
b) Cons
- A clear path is needed for sunlight to enter the house.
- Any objection in the path of sunlight reduces its efficiency.
- Bills from heating devices are not completely eliminated but only reduced to some extent.
- Heat absorbed only serves one purpose heating and cannot be converted into electricity.
- It is not as effective as active solar heating systems.
To sum up, here is a table of comparison between the two heating systems.
| Parameters | Active Heating System | Passive Heating System |
| Collection of solar energy | In separate containers | Within elements and items of the house with high thermal mass |
| Cost | Expensive | Less expensive |
| House | Used in any type of house | Properly planned house structure required |
| Location | Can be easily installed anywhere | Places with enough sunlight are mandatory |
| Mechanical equipment | Required to collect and distribute the heat | Not required |
Also See: Connecting Solar Panels in Series Vs Parallel
Is Active or Passive Solar Better?
Both active and passive solar energy have their pros and cons. However, considering whether active or passive solar is better you need to consider a few points.
- Power source: Active solar energy does not need any other power source except the sun and passive solar energy relies more on the weather.
- Devices: Active solar system uses solar panels that are easy to maintain, and the self-dependent and passive solar system uses thermodynamics.
- Cost: Active solar systems are costly as they include the installation of solar panel systems and passive solar energy is affordable.
So, if you prefer less costly things, you can consider passive solar energy but personally speaking, active solar is better. The reason being is that the heat and energy generated through this active system can be used for other purposes additionally like running other household appliances. with this, you have should have understood is active or passive solar better.
So, learning about how does active solar energy work and how it helps in reducing carbon footprints was interesting. However, in active solar heating vs passive solar heating one thing became clear. If you value efficiency, then an active solar heating system is the best; otherwise, you have another option too. By the way, do you use solar heating systems? We would love to hear your reviews on the same and which one you prefer among them.
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