How Do Solar Panels Work?
Thanks to a combination of improving technology and lower costs, solar use has expanded at an unprecedented rate over the last ten years. In fact, according to the International Energy Agency, it’s currently the world’s fastest-growing source of power, accounting for two-thirds of all new capacity in 2016.
Is solar right for you? Given the flexibility and sophistication of today’s systems, the answer is probably “yes.” However, to make an informed decision, it helps to have a bit of background about how the technology works and what your installation options are.
That’s why we’ve put together this handy guide covering the basics of how solar panels produce energy and some of the potential ways you can incorporate them into your home.
What Is Solar Energy?
On one hand, solar energy can seem a bit like magic. But while the science behind it is complicated, there’s no mystery to how it works. Sunlight is composed of tiny, weightless particles called photons. These photons carry a small amount of electromagnetic force which, with the right equipment, can be converted into usable energy.
Researchers estimate that, every hour, the sun radiates enough energy to power the entire world for a year. While our current technology and infrastructure are still far away from capturing even a fraction of that amount, it’s clear that solar has the potential to keep growing and become a much more significant source of power for both residential and commercial properties.
How Solar Panels Work, Step by Step
The photovoltaic (PV) cell is the most critical part of a solar panel. PV cells do the work of converting photons into usable energy. As such, they play a significant role in determining the effectiveness and efficiency of the overall system. A PV cell consists of thin layers of silicon or a similar semiconducting material. In a typical PV cell, the top layer is coated (“seeded” or “doped” in industry-speak) with phosphorus to create a negative charge. The bottom layer is seeded with boron, creating a positive charge. In between the two is what’s known as the “silicon junction” — a kind of electrical circuit.
When sunlight hits the top of a PV cell, its photons knock loose a group of electrons that enter the silicon junction, generating a charge. On the sides of the PV cell are a series of conductive plates. These are often made from silver, though next-gen solar panels are experimenting with cheaper, easier-to-source materials in an effort to bring costs down. The electrical charge is carried away by these conductive materials, where it is converted into usable electric power.
To understand how far PV technology has come, some history is useful. The photovoltaic effect was first observed in 1839 by French physicist Edmund Becquerel, though it would be almost a century before we understood the scientific basis for it. It was not until 1954 that Bell Labs developed the first workable solar cell, and it was still another two decades before the technology was advanced enough for commercial use. In 1978, President Jimmy Carter signed the Solar Photovoltaic Energy Research, Development and Demonstration Act, ushering a period of rapid technological advancement.
Early adoption of solar power was slow in part because of the low efficiency of PV technology. Generating enough solar power to run a property required large arrays, basically limiting its usefulness to rural, commercial and off-grid properties. In 1985, the University of South Wales became the first to break the 20 percent efficiency barrier. Less than a decade later, in 1994, the National Renewable Energy Laboratory produced a solar cell capable of exceeding 30 percent conversion efficiency.
In the years since then, PV cells have gotten smaller, more affordable and more suitable for widespread use. A typical residential system will convert between 16 and 22 percent of energy from the sun into usable power.
Other Components of a Solar Installation
PV cells are only one part of a solar installation. In order to generate power for a home or business, a solar installation also requires, at a minimum, the following:
- A mounting system: Solar panels produce the most energy in direct sunlight. As such, how and where they are mounted will affect their efficiency. Mounting systems can be fixed in place or mechanically repositioned over the course of the day to maximize exposure. The roof is a natural place to mount a solar installation, though businesses and larger properties incorporate PV cells into their parking canopies, eaves and other building components.
- An inverter: Solar panels produce DC (direct current) electricity, which is different from the AC (alternating current) power required by most homes and businesses. For this reason, an inverter is essential for home solar use. Though not expensive, inverters range in size and specification. Choosing the right one for your home requires a careful consideration of your energy needs.
A solar array disconnect: A solar array disconnect is an important safety feature that disconnects the solar array for maintenance or repair purposes.
Individual components of a solar installation must work together, which is why it’s important to partner with an installer you can trust. Understanding the various models and systems available today requires professional expertise. As with anything related to your home’s power, a solar installation requires consultations with a qualified electrician and engineer, too.
Grid-Tied vs. Standalone Systems
The above components provide everything you need for a simple solar installation. However, such a barebones system will only run when the sun is out and contains no backup option for when it isn’t. It’s for this reason that a majority of home and small business solar systems remain connected to the conventional power grid. This has several advantages:
- It ensures there is a reliable source of power available when your system isn’t generating enough on its own
- It allows for smaller, more affordable installations that offset your reliance on fossil fuels without requiring you to power your entire property
- In some areas, it allows you to generate income by selling excess power back to your utility provider
Grid-tied systems can be configured to switch between utility and solar power automatically. Many people with this type of system also install a power meter to show them in real-time how much usable electricity their solar system is generating and how much is coming from the grid.
While grid-tied solar panels are increasingly the norm, standalone systems are still an option for anyone who lives in a remote area or wants to be truly energy-independent. Nearly all standalone solar systems include a set of deep cycle batteries and a charge controller. These batteries — similar to those found in electric cars — store excess energy for use in the nighttime or during overcast periods when the system isn’t working at full efficiency. A charge controller automates the process and ensures that adequate power is coming to and from the battery at all times.
While they no longer face the same reliability issues as they did in the past, standalone systems don’t qualify for as many tax incentives and rebates and don’t provide the option of generating additional revenue by selling back to the grid. As such, with a standalone system, your path to recouping your initial investment is longer.
What to Expect From a Solar Installation
All the technological and technical changes that have occurred over the past twenty years have had the cumulative effect of making solar one of the most versatile and flexible power options available today. With solar, you enjoy freedom from unpredictable energy pricing and freedom to design a system that works for your property and your budget. That can mean anything from a small array supplementing your reliance on the grid to a community-based system powering several houses at once.
Solar is no longer a large array of panels generating unpredictable and insufficient power. Today’s solar systems integrate seamlessly with your home and your life. New payment structures — including tax incentives and financing opportunities — have made making the switch increasingly affordable, too.
Bright Eye Solar is a leading provider of residential and commercial solar installations in Pennsylvania, Maryland, New Jersey, New York, Delaware. We work with customers every step of the way to make going solar straightforward. Check out the following links to learn more:
Check out the links below to learn more about our services!