Solar panels have become increasingly popular in the ever-growing quest to find a source of renewable energy that would also be an environment friendly. But why is that so?
Solar panels convert sunlight into electricity which can be used to power your home, business, or just about anything that requires electrical power.
In this blog post, we will discuss further into how solar panels work, the different types of solar panels available on the market today, and how to determine their efficiency.
#1. What Is ‘Solar Power’?
We all enjoy the Sun’s light and warmth when playing outside or having fun at the beach. We also know that it’s essential for almost every living creature and plant on the planet, but what is this light we see and feel, and what is it made of?
The Physics Behind
Physicists refer to light both as a wave and as a particle. A light that travels through space is considered an electromagnetic wave. Light is also considered to be made of zero mass particles, called “photons”. Each photon in a light beam carries a specific amount of energy that depends on its electromagnetic frequency, which is proportionally opposite to said light’s wavelength (the higher the frequency, the lower the wavelength, and vice versa).
The process of converting the energy carried by photons into thermal or electrical energy is called Solar power.
#2. Solar Cell: From Photons To Electricity
The conversion of light energy into electrical energy is a physical and chemical phenomenon known as the photovoltaic effect.
How Its Structured
Solar cells (or photovoltaic cells – PV for short) are devices that are designed to utilize this effect, and they are the key component in solar panels. A solar cell is typically made from two layers of semiconductor material (silicon being the most common one). The bottom layer is the p-type silicon, a silicon that has been modified to contain more protons than electrons, and the top layer is the n-type silicon – a silicon has been treated to contain more electrons than protons.
When solar cells are exposed to sunlight, the semiconductor absorbs a percentage of the light (photons) causing its energy to be transferred to the material. This extra energy causes electrons to break off and flow freely. The amount of free-flowing electrons in a solar cell depends on the material it’s made of and the amount of sunlight it is exposed to.
In addition, the solar cell’s electric field forces electrons set free by the mentioned light absorption to flow in a particular direction – and that flow is called ‘a current’.
With proper metal contacts on both the top and bottom of the PV cell, the current can be directed to a specific target and used to power different devices.
#3. One Solar Panel – Many Solar Cells
A single solar cell can produce enough energy to power a small appliance, like a calculator. But in order to produce enough electricity for your house or business, you would need multiple solar cells connected together – to form what is known as a “solar panel.”
The amount of output power solar panels produce depends on two main factors: the number of photovoltaic cells they are made of, and the wiring design between the cells – which can be parallel or in series. Similar to a manner of connecting batteries, wiring solar cells in series increases the panel’s potential difference (voltage), while wiring in parallel increases the current.
For example, on average, a 26x52mm cell with 17.4% solar energy conversion efficiency rate can output up to 0.2 watts (0.487A and 0.518V). Therefore a smartphone charger based on solar technology that produces DC electricity with 7.5 watts of output power, will contain three rows of parallel-wired cells, with each row consisting of ten cells wired in series, and so 30 cells in total.
#4. So, How Do Solar Panels Work? And What To Look Out For?
The theoretical part of solar energy is worth knowing, but unless you are into renewable energy DIY related projects, you will most likely not be dealing with building solar modules from scratch. Luckily, there are many solar energy generation solutions and solar energy production systems available on the market.
So, putting that aside, how do solar panels work? and what should you pay attention to?
What Should You Really Consider
Putting it simply, a solar panel converts solar energy into electricity. The important thing to note is that it is DC electricity. Unfortunately, most of our electrical devices use AC electricity as a power source. Therefore, any solar energy system that utilizes the sun’s energy must be equipped with a solar inverter that inverts DC into AC if you wish to use it at home or at an office.
In general, installing a solar panel system can be expensive and comes with regular maintenance. In order to estimate if such a house upgrade will be worth the investment, you should first estimate the amount of power your home consumes on average during a full day.
How Much Does It Cost?
On average, a residential utility customer consumes around 28kWh of AC electricity a day in the U.S. With solar modules cost ranging between $0.9 to $1.5 per Watt, depending on the module’s efficiency, covering your daily power consumption can cost between $25,200 to $42,000 worth of panels only, excluding work expenses. Alternatively, you can choose a less expensive (but also less efficient) type of panels, thus saving a decent amount of money, but it will come at the cost of space, as you will have to install a larger number of modules, take it into consideration when choosing solar panels.
Nowadays, the average price of 1kWh in the U.S is 15.42 cents ($0.1542), which means power consumption in a day costs around $4.317, adding up to $1,576 a year – meaning that the less expensive version of a solar panel system will pay for itself after around 16 years. This is good news, considering a solar PV cell can hold up for around 20 to 25 years, and will keep generating electricity if maintained regularly. Due to the fact that a photovoltaic cell absorbs sunlight to generate DC current, it is important to keep the panels as clean as possible and wash them regularly, in order to avoid major problems.
Solar System Benefits
Choosing to upgrade your home to utilize solar energy have its advantages, for example, it can save you up to $14,000+ in the long term. Moreover, if you have a lifestyle of spending most of your daily hours outside your house and not consuming electricity during those hours, you can definitely use solar generators to your advantage. Solar generators are designed to be accumulative storage devices that store solar electricity which can be accessed when needed. For example, at night time when sunlight can’t be used as an energy source.
Leaving The Grid
In a case where your everyday activity doesn’t depend on high electrical power consumption, or you just prefer a lifestyle of independence, assembling a solar energy system with a solar generator designed for off-grid living is the perfect choice for you. Those types of generators usually come with a high energy storage capacity and multiple storage expansion capabilities.
Needless to say that solar energy is an environmentally green source of energy, and every home that chooses to be powered by that source, has a direct impact on the quantity of carbon dioxide and other carbon compounds emitted due to the consumption of fossil fuels, therefore decreasing the world’s carbon footprint.
#5. Solar Panels Types To Be Familiar With
Solar modules are generally classified by the type of materials used in their making. The three most common types of solar panels are:
- Crystalline Silicon (c-Si)
- Concentrator Photovoltaics (CPV)
The vast majority of solar panels installed today are c-Si, also known as first-generation solar panels. They are made of a single pure silicon crystal or polycrystalline silicon, also called ingots. The c-Si solar cells are cut from the ingots and assembled into modules (solar panels).
c-Si solar panels have the highest efficiency rates (up to 22.0%) among all the solar panel types, with a lifespan between 25 to 30 years, which is about twice as long as Thin-Film solar panels.
Thin-Film solar cells are made by depositing one or more layers of photovoltaic material on a substrate. The most common thin film materials are:
- Amorphous Silicon (a-Si)
- Cadmium Telluride (CdTe)
- Copper Indium Gallium Selenide (CIGS).
The use of those materials makes Thin-Film solar panels cheaper and more flexible to manufacture than c-Si, in addition to the lower weight per unit area.
Concentrator Photovoltaics (CPV) solar panels are a type of high-efficiency solar panel that uses lenses and mirrors to concentrate sunlight onto small, highly efficient photovoltaic cells. CPV panels are typically used in large solar power plants where land is scarce, and the high efficiency of CPV panels offsets the cost of the tracking system required to keep them pointed at the sun. However, CPV systems are also being used on a smaller scale in some residential and commercial solar installations.
The main advantage of CPV panels is their high efficiency, which can be as high as 40% for commercial panels and up to 60% in some research prototypes. That is a much higher rate than the efficiency of c-Si and Thin-Film solar panels that are typically in the range between 15-20%. The higher efficiency of CPV panels allows them to generate more electricity per square meter than other types of solar panels, making them ideal to use in both small spaces and areas with high levels of sunlight.
Q & A
How do solar panels work step by step?
Solar panels work by converting the energy from the sun into electricity. The process begins when sunlight hits the solar panel and is absorbed by the semiconductor material. This absorption of light causes the electrons in the semiconductor to become excited and break free from their atoms. These electrons flow through the solar panel and generate an electric current. This current can then be passed through an inverter and converted into AC power, which can be used to power homes and businesses.
What are the 2 main disadvantages to solar energy?
The main disadvantages to solar energy are firstly the initial cost of solar panels, and secondly the dependence of working only when there is direct sunlight. Solar panels can be expensive to purchase and install. Additionally, solar panels only produce electricity when they are directly exposed to sunlight. This means that solar panels will not work at night or on cloudy days.
How long do solar panels last for?
Solar panels typically last for 20-25 years. However, the lifespan of a solar panel can be affected by factors such as weather and air, their care and the materials they are made of.
How many solar panels would it take to power a house?
The number of solar panels needed to power a house depends on the size of the house and the amount of electricity that is used by its residents. On average, it takes between 20-30 solar panels to power a house. However, this number can vary depending on the home’s specific needs.