How do Solar Panels Work

As the cost of solar energy has plummeted in recent years alongside major improvements in technical efficiencies and manufacturing quality, many homeowners across the Pakistan are starting to look at solar as a feasible alternative energy solution. And as solar enters mainstream energy markets, the big question is, “how do solar panels work?” In this article, we’ll break down exactly how solar panels produce energy for your home and how sensible going solar really is.

How do Solar Panels Work? Step by step overview

Solar panels work by absorbing sunlight with photovoltaic cells, generating direct current (DC) energy and then converting it to usable alternating current (AC) energy with the help of inverter technology. AC energy then flows through the home’s electrical panel and is distributed accordingly. Here are the main steps for how solar panels work for your home:

1. Photovoltaic cells absorb the sun’s energy and convert it to DC electricity
2. The solar inverter converts DC electricity from your solar modules to AC electricity, which is used by most home appliances
3. Electricity flows through your home, powering electronic devices
4. Excess electricity produced by solar panels is fed to the electric grid

How do solar panels generate electricity?

A standard solar panel (also known as a solar module) consists of a layer of silicon cells, a metal frame, a glass casing, and various wiring to allow current to flow from the silicon cells. Silicon (atomic #14 on the periodic table) is a nonmetal with conductive properties that allow it to absorb and convert sunlight into electricity. When light interacts with a silicon cell, it causes electrons to be set into motion, which initiates a flow of electric current. This is known as the “photovoltaic effect,” and it describes the general functionality of solar panel technology.

The photovoltaic effect

The science of generating electricity with solar panels all comes down to the photovoltaic effect. First discovered in 1839 by Edmond Becquerel, the photovoltaic effect can be generally thought of as a characteristic of certain materials (known as semiconductors) that allows them to generate an electric current when exposed to sunlight.

The photovoltaic process works through the following simplified steps:

1. The silicon photovoltaic solar cell absorbs solar radiation
2. When the sun’s rays interact with the silicon cell, electrons begin to move, creating a flow of electric current
3. Wires capture and feed this direct current (DC) electricity to a solar inverter to be converted to alternating current (AC) electricity 

How does grid connection work with solar panels?

Though electricity generation with solar panels may make sense to most people, there’s still a lot of general confusion about how the grid factors into the home solar process. Any home that is connected to the electrical grid will have something called a utility meter that your energy provider uses to measure and supply power to your home. When you install solar panels on your roof or on a ground mount on your property, they are eventually connected to your home’s utility meter. The production of your solar system can actually be accessed and measured by this meter.

Most homeowners in the Pakistan have access to net metering, a major solar incentive that significantly improves the economics of solar. If you have net metering, you can send power to the grid when your solar system is overproducing (like during the day in sunny summer months) in exchange for credits on your electric bill. Then, during hours of low electricity production , you can use your credits to draw extra energy from the grid and meet your household electricity demand. In a sense, net metering offers a free storage solution to property owners who go solar, making solar an all-in-one energy solution.

Additional important parts to solar panels

Aside from their silicon solar cells, a typical solar module includes a glass casing that offers durability and protection for the silicon PV cells. Under the glass exterior, the panel has a layer for insulation and a protective back sheet, which protects against heat dissipation and humidity inside the panel. The insulation is important because increases in temperature will lead to a decrease in efficiency, resulting in a lower solar panel performance.

Solar panels have an anti-reflective coating that increases sunlight absorption and allows the silicon cells to receive maximum sunlight exposure. Silicon solar cells are generally manufactured in two cell formations: monocrystalline or polycrystalline. Monocrystalline cells are made up of a single silicon crystal, whereas polycrystalline cells are made up of fragments or shards of silicon. Mono formats provide more room for electrons to move around and thus offer a higher efficiency solar technology than polycrystalline, though they are typically more expensive.