What Is The Correct Name For A Solar Cell?
Solar cells, which are also known as photovoltaic cells, are devices that convert sunlight into electricity. They go by several different names, including solar cells, photovoltaic cells, and PV cells. The term “solar cell” refers to a broad category of devices that convert light into electricity using the photovoltaic effect. There are many different types and generations of solar cells, each with their own specific materials and properties. But they all operate on the same basic principle of converting photons from sunlight into electrical current.
Photovoltaic Cell
The most accurate name for a device that converts sunlight directly into electricity is a “photovoltaic cell” (1). Photovoltaic comes from the Greek word photos meaning “light” and volt, meaning “electricity.” Therefore, photovoltaic literally translates to “light-electricity” (2). Photovoltaic cells are sometimes referred to as solar cells, but solar cell is a broader term that can refer to any device that converts sunlight into electricity. However, photovoltaic cell specifies that the sunlight is being directly converted into electricity through the photovoltaic effect (3).
While terms like solar panel or solar module may refer to an assembly of interconnected photovoltaic cells, the fundamental light-to-electricity converting unit is properly called a photovoltaic cell. This helps differentiate the core electricity-generating component from the overall system.
Sources:
(1) https://energyeducation.ca/encyclopedia/Photovoltaic_cell
(2) https://www.energy.gov/eere/solar/solar-photovoltaic-cell-basics
(3) https://en.wikipedia.org/wiki/Solar_cell
History
The first photovoltaic cell was invented in 1839 by French physicist Edmond Becquerel at the age of 19. Becquerel discovered the photovoltaic effect while experimenting with metal electrodes in a conductive solution exposed to light. He found that voltage and electric current were generated when light hit the electrode, a phenomenon now known as the photovoltaic effect. This marked the earliest beginnings of solar cell technology as we know it today (Source).
The next major development came in 1883 when American inventor Charles Fritts created the first true solar cells made from selenium wafers. Fritts’ solar cells had an efficiency of only around 1%, but they demonstrated the potential of solar power (Source).
However, it was not until the 1950s that practical solar cells were created. In 1954, researchers at Bell Laboratories developed the first silicon photovoltaic cell with a sunlight conversion efficiency of around 6%. This invention, led by inventors Daryl Chapin, Calvin Fuller, and Gerald Pearson, marked a major breakthrough that enabled widespread use of solar power (Source). Silicon solar cells paved the way for the modern photovoltaic industry.
How They Work
Solar cells or photovoltaic cells work through the photovoltaic effect. When sunlight hits the solar cell, the photons are absorbed by the semiconductor material in the cell, like silicon. This energy knocks electrons loose in the material, allowing them to flow freely. The PV cell has an electric field that acts to force these electrons to flow in a certain direction, creating an electrical current. Metal conductive plates on the front and back of the cell collect the electrons and transfer them to the external circuit. Wires connected to the positive and negative sides allow the current to then power an external load, like an appliance or device. This process of converting sunlight into electricity is called the photovoltaic effect.
In summary, the key steps are:
- Sunlight hits the PV cell surface and gets absorbed.
- The energy from the photons knocks electrons loose in the semiconductor material.
- The cell’s electric field causes the electrons to flow in one direction.
- The electron flow creates an electrical current.
- Metal plates collect the electrons and transfer them to the external circuit.
This basic operating principle allows photovoltaic cells to generate electricity from sunlight without any moving parts or environmental emissions.
Other Common Names
While “solar cell” is the correct term for describing an individual electricity-generating unit, there are some other common names that are frequently used:
- PV cell: This stands for “photovoltaic cell” and refers to the photovoltaic effect that allows solar cells to convert sunlight into electricity.
- Solar panel: This refers to a panel consisting of multiple interconnected solar cells. Solar panels are made up of many individual solar cells wired together to generate higher voltages and power.
The terms “solar panel” and “solar cell” are sometimes used interchangeably, but they refer to different things. Solar cells are the individual units, while solar panels contain many solar cells wired together in a panel.
Advantages
The main advantages of photovoltaic cells are they provide a renewable source of electricity. Since the energy comes from the sun, they provide a sustainable source of power for as long as the sun shines. Unlike fossil fuels which have a limited supply and release harmful carbon emissions when burned, solar energy is replaced every day by the sun.
In addition, photovoltaic systems require low maintenance. Once installed, they can operate for decades with little human intervention, besides occasionally cleaning the panels. This reduces the overall costs and operations over the panel’s lifetime.
Finally, solar cells generate electricity without releasing any greenhouse gases or other pollutants. This is a significant advantage over traditional fossil fuel power plants, which are a significant contributor to climate change and air pollution. By providing clean energy, photovoltaics help reduce the environmental impact of our energy usage.
Disadvantages
Solar photovoltaic cells do have some disadvantages that need to be considered:
One disadvantage is that photovoltaic cells are still quite expensive to manufacture, install, and maintain compared to other sources of electricity. The initial investment required for a solar panel system is significant.
Another disadvantage is that most photovoltaic cells today still only have a relatively low efficiency, usually between 15-20%. This means most of the sunlight that hits the panels gets converted into heat rather than electricity.
There are also concerns that some photovoltaic cells contain toxic materials like arsenic and cadmium that can pose environmental hazards if not disposed of properly. The manufacturing process itself can also involve harmful chemicals and produce toxic byproducts if not carefully regulated.
Overall, while solar power from photovoltaics provides clean renewable energy, the technology does have some downsides to consider regarding cost, efficiency, and environmental impacts.
Efficiency
The conversion efficiency of a solar cell refers to the percentage of sunlight energy that the cell can convert into electricity. This is a key metric in evaluating and comparing different solar cell technologies.
According to the U.S. Department of Energy, most commercial solar panels have efficiencies between 15% and 20%.1 Higher efficiency solar cells are able to convert a greater fraction of the solar energy into electrical energy. However, higher efficiency often comes with a tradeoff of higher cost of production.
Current solar cell technologies using crystalline silicon have achieved maximum efficiencies around 25% in lab conditions.2 Other semiconductor materials like gallium arsenide have reached even higher efficiencies above 30% in research settings.3 However, translating these high efficiency designs into affordable commercial products remains an ongoing challenge.
In real-world operating conditions, factors like shading, dust buildup, and high temperatures can reduce the conversion efficiency substantially below the optimal lab ratings. Proper solar panel maintenance is therefore critical for maintaining efficiency over the system lifetime.
1. https://www.energy.gov/eere/solar/solar-performance-and-efficiency
2. https://en.wikipedia.org/wiki/Solar_cell_efficiency#Crystalline_silicon
3. https://en.wikipedia.org/wiki/Solar_cell_efficiency#High_efficiencies
Applications
There are many different applications for solar photovoltaic cells. The most common applications are at the residential, commercial, and utility scale.
For residential applications, solar PV systems are installed on the roofs of homes to generate electricity. Typical system sizes range from 5-10 kW. The solar electricity generated is used to power home appliances, lights, heating/cooling systems and can also be fed back into the grid. According to the National Renewable Energy Laboratory (NREL), over 2 million homes in the United States have installed solar PV systems as of 2018 [1].
At the commercial level, solar PV systems are installed on the rooftops and grounds of warehouses, offices, schools and other buildings. System sizes tend to be larger than residential, ranging from 10 kW to 5 MW. The generated electricity is used to power the building’s electric loads. Major companies like Apple, Amazon, Target, Walmart and others have installed solar on their facilities to reduce electric bills [2].
Utility-scale solar refers to large PV plants that generate power for the electricity grid. These systems have capacities in the range of 10-100 MW. According to the Solar Energy Industries Association (SEIA), there are over 300 utility-scale solar plants operating in the U.S., with a total capacity of over 30 gigawatts [3]. The falling price of solar has made it cost competitive with fossil fuels for bulk power generation.
Conclusion
In summary, the technically correct term for a solar cell is a photovoltaic cell. While solar panel and solar cell are commonly used names, photovoltaic cell is the most accurate term referring specifically to a device that converts sunlight directly into electricity through the photovoltaic effect. When connecting multiple cells together into modules and panels, the complete assembly may be referred to as a solar panel system. But at the core, the specific component that generates electricity from light is called a photovoltaic cell. Hopefully this outline has provided a comprehensive overview explaining the proper name and key facts about photovoltaic cells.
