The difference between photovoltaics and solar energy. 1 accurate article make it clear!

As two important renewable energy technologies, solar energy and photovoltaics are playing an increasingly important role in our daily lives. Well, do you know the difference between photovoltaic and solar energy?

Solar energy and photovoltaics

The main differences between photovoltaic and solar energy are working principle, application fields and energy conversion efficiency. Photovoltaic technology directly converts sunlight into electrical energy through the photoelectric effect of semiconductor materials. It is mainly used in fields such as solar cells. The conversion efficiency is generally between 15% and 20%. Solar technology more broadly covers the process of using solar thermal energy to generate electricity, such as solar water heaters and solar thermal power stations, and its conversion efficiency depends on the specific application and technology. Overall, photovoltaics are an efficient and direct way to utilize solar energy, while solar technology is more diverse and widely used.

Let’s take a closer look at the differences between them.

Differences in working principles

Photovoltaic technology, also known as PV technology, works mainly based on the photoelectric effect. Simply put, when sunlight strikes a photovoltaic cell made of a semiconductor material, the photons interact with the atoms in the material, causing electrons to be released from the atoms, forming an electric current. Due to the properties of solar cell materials, this process of directly converting sunlight into electrical energy without any intermediate process makes photovoltaic technology an efficient and direct way to utilize solar energy.

Solar technology covers a wider range of ways to use sunlight for energy conversion. In addition to the photovoltaic effect, solar technology also includes the application of solar thermal energy. Solar water heaters and solar thermal power generation are two important applications of solar technology. Solar water heaters heat water by absorbing heat from sunlight to meet the hot water needs of homes or public places. Solar thermal power generation collects solar heat through a heat collection device, and then uses this heat to drive a steam turbine to generate electricity. This method requires converting solar energy into thermal energy, and then converting thermal energy into electrical energy, so the energy conversion process is relatively complex.

Characteristics of application areas

Photovoltaic technology has been widely used in many fields because it can directly convert sunlight into electrical energy. Solar panels are a typical application of photovoltaic technology. They are installed on rooftops, open fields and even oceans to convert sunlight into electricity, providing clean, renewable energy for homes, businesses or public facilities. In addition, photovoltaic technology is also used in solar street lights, aerospace, railway transportation and other fields to provide convenient and efficient energy solutions for these fields.

Solar thermal power generation is mainly used in fields such as solar water heaters, solar heat pumps and large-scale solar thermal power stations. Solar water heaters are commonly used water heating equipment in homes and businesses. They use solar heat to heat water and are energy-saving and environmentally friendly. Solar heat pumps use solar heat to provide cooling or heating functions, providing a comfortable indoor environment for buildings. Large-scale solar thermal power stations use heat collection devices to collect a large amount of solar energy heat, and convert the heat energy into electrical energy through heat exchangers, steam turbines and other equipment to provide stable power output for the power grid.

The utilization of solar energy reduces carbon emissions and promotes sustainability
The utilization of solar energy reduces carbon emissions and promotes sustainability

Differences in equipment structure

Photovoltaic equipment usually consists of solar panels, brackets, inverters and batteries. Solar panels are the core component of photovoltaic equipment, responsible for collecting light energy and converting it into electrical energy. The bracket is used to support and fix the solar panel to ensure that it receives sunlight stably. An inverter converts the direct current generated by the solar panels into alternating current for use in a home or business. The battery is used to store excess electrical energy to provide power during periods of no sunlight such as at night or on cloudy days.

The solar thermal power generation system includes heat collectors, heat exchangers, heat storage equipment and generators. The collector collects solar heat and transfers it to the heat exchanger. The heat exchanger transfers heat energy to the working medium, such as water or steam, so that it reaches the temperature and pressure required for power generation. Thermal storage equipment is used to store excess heat to provide stable heat output when needed. The generator converts the thermal energy of the working medium into electrical energy to provide power output for the power grid.

Comparison of environmental protection levels

Photovoltaic technology produces no pollution and does not emit greenhouse gases during the power generation process. It is a green and environmentally friendly way of utilizing energy. Thanks to powerful light trapping technology, the installation and operation of photovoltaic equipment does not require the burning of any fossil fuels, so its environmental impact is small. In addition, photovoltaic equipment will not produce noise, radiation and other pollution during operation, and will have less impact on the surrounding environment and residents’ lives.

In contrast, solar thermal power systems may require the use of fossil fuels as an intermediate medium in some applications, such as during the start-up phase or when supplementing heat. This may bring some environmental pollution, although this pollution is far less than traditional fossil fuel power generation methods. However, with the advancement of technology and the improvement of environmental protection requirements, more and more solar thermal power generation systems are beginning to use clean and renewable energy as auxiliary heat sources to reduce environmental pollution.

Differences in energy conversion efficiency

The conversion efficiency of photovoltaic technology mainly depends on the performance of photovoltaic materials and manufacturing processes. At present, the conversion efficiency of commercial photovoltaic panels is generally between 15% and 20%. With the continuous advancement of technology and the development of new materials, this efficiency is expected to be further improved. At the same time, photovoltaic technology has less energy loss, making it highly efficient in the energy conversion process.

The efficiency of solar thermal power generation depends on the efficiency of the heat collection device, the performance of the heat exchanger and the heat loss of the entire system. Since solar thermal power generation involves the transfer and conversion of thermal energy, its efficiency may be affected by a variety of factors, such as the type and area of ​​the heat collection device, the nature and state of the working medium, etc. Therefore, the efficiency of solar thermal power generation will vary in specific applications. In order to improve the efficiency of solar thermal power generation, researchers are constantly improving the design of heat collectors and heat exchangers, as well as optimizing the operation of the entire system.

write at the end

In one sentence, although photovoltaics and solar energy are both related to sunlight, they have obvious differences in working principles, application fields, equipment structures, environmental protection and energy conversion efficiency. As renewable energy sources become increasingly important, we should gain a deeper understanding of these technologies in order to better utilize the endless energy treasure trove of solar energy.

Harnessing solar energy through photovoltaic panels converts sunlight into electricity
Harnessing solar energy through photovoltaic panels converts sunlight into electricity