In this article, we shall discuss how do solar panels generate electricity and other related topics. The existence of the Sun has been a crucial factor to the progress and evolution of all life forms on earth. The solar energy it emits provides heat to the earth, provides natural light, regulates weather and climate, and sustains plant and animal life.
Plants and algae capture light through photosynthesis, converting it to energy molecules, which powers the whole food chain. The Sun’s impact allowed organisms to develop, to benefit, and to adapt with the earth’s continuous transformation. Nearly all available energy on Earth is accounted to the sun, with exceptions from radioactive material, moon tides, and geothermal energy.
Everything else can be attributed to the sun as a converted form of its energy. Fossil fuels which power the conventional power plants are from organic life which thrived on the food chain primarily dependent on plant’s survival through sunlight.
The Sun’s uneven heating of the atmosphere causes winds beneficial for wind power. Solar heat produced by the Sun drives the water cycle, creating water flow for hydropower. and The production of photovoltaic energy by converting the energy in sunlight into charged particles for electricity, through solar power systems.
When we think of solar panels, what usually comes to mind are the large rectangle facing the sun on wide fields, or above household roofs, but those are actually called solar arrays. Solar arrays are collections of solar panels assembled together.
These solar panels are comprised of solar cells, the smallest unit of a solar power system. Throughout the paper, we will use the terms solar cell and photovoltaic (PV) cell interchangeably.
How Do Solar Panels Generate Electricity?
A basic PV cell is a pn junction diode. It is a basic semiconductor device which controls the flow of electric current in a circuit. It has a positive (p) side, and a negative (n) side. Most of the diodes used in solar cells are made with silicon, which allows the diode to perform at higher temperatures, preventing overheating. In making pn junction diodes, impurities are added to each side in a process called doping.
The chemical properties of silicone indicate that it has four valence electrons, which are all used when they are bonded together. The impurities are added to enhance the performance of energy conversion. Phosphorus and Boron are integrated to the positive and negative sides of the diode respectively.
As both sides touch each other, imbalance of charges are made inside the PV cell, creating voltage from electric fields. Initially as these sides are brought together, a rush of electrons shall form a barrier between the sides until reaching equilibrium, where energy is required for the electrons to move again, which is energy from incoming light. This is how each cell from a solar panel generate electricity.
How do solar panels work?
A standard solar panel consists of the following parts from top to bottom: Frame, Glass, Encapsulant, Solar Cells, Back Sheet, and the Junction Box. The frame protects the edge the panel, houses the cells, and provides a solid structure for mounting the panels in place. They are made to withstand external forces and stress.
The glass protects the cells from various kinds of debris and the fickle weather. The glass is typically 3-4mm thick, usually tempered glass that is designed to resist intense temperature changes and sudden, extreme force.
Encapsulants prevent water and dirt from infiltrating the solar panels and protects the solar cell by isolating the cells from the glass and the back sheet, minimizing the impacts of shocks and vibrations. Encapsulants are usually made of ethylene vinyl acetate (EVA), which provide quality radiation transference, and slower deterioration from sunlight.
The solar cells convert light from the sun into DC electricity. The electrical current is extracted through contact with the grid lines of solar cells, which are conductive metals. The cells are pn junction diodes which are activated through solar energy. The back sheet serves as the protective barrier, providing protection and electrical insulation. The back sheets are durably made to provide UV resistance and thermal stability.
Lastly, the junction box is an external enclosure where the bypass diodes and solar connectors are kept. The bypass diodes enable current to flow and eliminate the hot-spot phenomena which damage the solar cell. The solar connectors, commonly the MC4 are used for connecting the solar panels.
How do solar panels generate electricity at home?
Typically, residential solar arrays are installed on house roofs. The installation must first be surveyed, to check the area of installation and to determine the angle appropriate for maximal sunlight utilization throughout the day.
The installation process is also coordinated with the local electric utility company, as the inverter uses electricity in its conversion. The installed panels convert the solar energy to electrical current. The generated electricity is then transported to the solar power system’s breaker.
It protects the system wiring from overheating. It also protects the inverter from short circuits and other related damages. The energy then goes to the inverter. The inverter converts the DC output of the solar panel to AC. The converted energy is then returned back to the inverter’s breaker, then to the house’s main breaker. Then the electricity produced can be readily available for household usage.
As long as there is sunlight, the solar panel system would continue to produce electricity. The electricity meter of the house with solar power system would be changed from the standard consumer meter to net metering.
Net metering allows the two-way movement of the meter. The excess electricity produced by the solar arrays would then be sent to the electric utility company’s lines, which would reverse the meter, deducting the metered usage of the company’s energy.
Can solar panels work at night?
Energy from sunlight which is abundant during daytime, is the main source of electricity of solar power systems. Even though the moon reflects light from the Sun, it will produce little to no energy. The main source of energy during nighttime would be from the local electric utility company.
Electricity harnessed from solar energy may be utilized at night, through off-grid solar power systems, using solar batteries. This would primarily store excess electricity produced during the day to be available for electrical consumption at night. Should there be an excess production of electricity, it will go to the electric company’s lines, deducting the metered usage of the household.
Residential Solar batteries available for purchase has capacity ranging up to 10Kw of electricity. If electricity stored through the batteries runs empty, the system will switch electricity source from solar into consuming electricity from the electric company.
Can solar panels generate enough electricity for a house?
Since the pandemic began, a lot of people are bound to their homes, utilizing all sorts of technology for studying, work, chores, and entertainment. This causes a rise in electricity demand in the household. Solar panels are able to generate enough electricity for a house, but there are a number of things that we should take into account.
First, we should assess our Daily average consumption of electricity. Our electricity consumption will determine the most appropriate type of solar panel that a consumer should acquire for their household.
Second, we should assess whether the location of our home is suitable for a solar power system. Many of households here in the Philippines are surrounded by trees, some of which block the sunlight from our roofs. In urban areas, high buildings cast shadows which blocks sunlight to infrastructure with lower heights.
Third, we should also take into account our capacity to purchase. Although prices are decreasing over time, solar panels are still costly, and purchasing a system is really an investment. Availing solar power systems require meticulous planning and dedication.
Are solar panels good investment?
As the demand for electricity rises, the rates of electric utility company go higher, with increasing costs in electricity production of conventional power plants. Having a solar power system would be a great long-term investment. Solar panel systems would reduce the costs of electricity for your household.
As it utilizes energy from the sun which is greatly abundant, there is no need to worry about running out for the next couple of billion years. Generating your own electricity is a huge perk by itself. You would be able to allocate the supposed funds for electricity bills to pay for other expenses. Also, if you use minimal electricity per day, the excess production of your solar power system would be sent to the electric company’s electric line, making profits for yourself.
Installation of solar panels may seem costly and time consuming at the beginning, yet consumers would be able to enjoy instant benefits after the installment of solar power systems. For a household with a monthly electric bill of $100.00, the average return on Investments would be within 3 to 4 years.
How many solar panels does it take to run a house?
To compute how many panels are needed to run a house, we need to determine your Direct Sunlight Daily Average, Daily Average Consumption, and panel wattage. The average time for direct sunlight is about 4.5 hours a day. We only compute the time with direct sunlight as it imposes the highest level of efficiency of the solar panels.
The panel wattage of a standard solar panel is around 300 watts. For example, a household’s monthly average consumption is around 441 KWH/30 Days, amounting to 14.7 KWH/day or 14,700 watts per hour a day. To determine the system setup that would be able to supply the average daily consumption, we need to divide the Daily Average consumption with the Direct Sunlight Daily Average.
As an estimate, we will multiply the result with 1.2% as our room for error, resulting to 3,920 watts. We will divide our daily watt usage with the panel wattage to determine the number of panels needed to run the house.
As a result, we will need around 13 panels for solar panel system to be able to supply the daily average consumption of a house with 441KWH/30days.
Are solar panels bad for your roof?
Solar panels are commonly installed in roofs, as there is more area for exposure to sunlight than other places within a consumer’s property. When installed in roofs, solar panels can maximize energy production.
Even In cloudy days, it will be able to produce 15% – 30% of its total energy production in a normal setting, In essence, solar arrays alone are not bad for your roof. However, the potential damages a roof might acquire could be from the installation process. The nails and bolts used to install the racks would leave holes to the roof, making them vulnerable to leaks over time.
Although more expensive, a consumer would like to opt for solar roof tiles, which would serve simultaneously as a solar power system and as a roof tile. This would minimize the need for nails and bolts. These roof tiles would be installed through the supervision of certified electricians which would ensure the safety and quality installment of the roof tiles.
The Sun has been the Earth’s unlimited source of energy for as long it has existed; empowering biomes, supporting life, and regulating the earth’s natural cycles. As technology progresses, we have learned to harness abundant energy from the Sun, which offers a promising future to the development of human society.
Solar panel systems for industrial and residential use bring plenty of benefits to humans and the environment. These systems are a cost efficient and eco-friendly way of generating electricity, while also allowing us to save financial liabilities. As we continue to learn how to utilize renewable resources, not only will it benefit humanity, but the world as a whole.