Active solar energy encompasses solar collection systems that use mechanical or electrical devices to enhance the efficiency of solar panels and to convert the captured solar energy into electrical or mechanical energy. These devices include fans, water pumps, and solar trackers, among others.
In contrast, solar systems that do not use such devices are classified as passive solar energy systems, which directly take advantage of solar radiation.
Active solar architecture
Active solar architecture is a branch of architectural design that focuses on incorporating specific systems and technologies to directly capture and use solar energy.
Unlike passive solar architecture, which focuses on the arrangement of architectural elements to maximize natural light and heat gain, active solar architecture involves technological components that convert solar radiation into usable energy, such as electricity or heat.
These active systems can include photovoltaic panels to generate electricity from solar radiation, solar thermal collectors that capture solar heat for water heating or space heating applications, and solar tracking systems that dynamically orient the solar panels to track the path of the sun during the day and maximize energy capture.
Types of active solar energy
Active solar energy can be photovoltaic and thermal.
Thermal solar energy
Solar thermal energy uses solar radiation directly to obtain heat. In general, this type of energy is used to supply domestic hot water. However, solar thermal power plants use this technology to generate electricity - so-called solar concentrators.
Domestic hot water and active solar heating
Domestic hot water (DHW) systems without thermosyphon use water pumps and other elements to circulate water within their circuits.
In thermosiphon systems, water circulation is carried out through the difference in densities between hot water and cold water. In this case, these systems do not need external mechanisms and are classified as passive solar energy systems.
Orientation of solar collectors
Most solar collectors are placed on fixed supports with a south orientation. The angle is calculated so that they can capture the greatest amount of radiation at all times. But these collectors would be more efficient if they could modify their orientation with respect to the Sun at all times.
Concentrated solar energy
In the case of concentrated solar energy, it is necessary to install solar tracking systems. This type of installation needs to focus the solar radiation received at one point. To achieve this, the mirrors have to adapt their inclination in relation to the position of the Sun.
The function of this type of system is used in solar thermal power plants with the aim of generating electricity.
Photovoltaic Solar Energy
Active solar photovoltaics is clearly an active system. Photovoltaic panels are responsible for generating electricity. The transformation into electrical energy is carried out in the photoelectric cells that make up the module.
Next, the generated energy passes through transformers and other external elements.
To increase efficiency we can direct the solar panels with the help of an electric motor. The optimal performance of a solar panel is obtained when the solar radiation hits perpendicularly.
Often these installations are converted into hybrid solar power plants. A hybrid solar system is a solar system that receives energy support from other energy sources. In this case, the energy source can be an electric generator or other renewable energy sources such as wind.
Differences between active and passive solar energy
An interesting hybrid method is to use a solar panel to operate pumps or fans. Data analysis, using heat thermodynamics software, can be used to compare the results of various active and passive solar strategies.
Passive solar systems require no additional energy to operate and therefore have zero maintenance costs. In addition, they do not emit greenhouse gases so they do not contribute to worsening climate change.