What Is Solar Energy?

What is Solar Energy?
Tim Robberts / Stone / Getty Images

For homeowners who are looking for clean energy solutions, solar power is utterly essential. But what is solar energy, exactly, and how does it work?

The Earth boasts many natural resources, but none as abundant as sunlight. As rays from the sun reach our planet, the energy they contain can be captured and used in a number of ways.

Before embracing residential solar power, it may be helpful to understand a bit more about what solar energy is, how it can be harvested and how it can be used. In this article, we'll offer a full solar energy definition, plus some basic guidelines about how it can be used in your home.

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Solar Energy Definition

Let's begin with a general overview of solar power.

The sun provides us with natural light during the day. In doing so, it sends individual particles of sunlight, known as photons, to the Earth. Each photon contains energy, and that energy fuels the Earth in various ways. It might surprise you to learn that, during any given hour, the Earth receives enough solar energy that it could theoretically fulfill the entire planet's energy needs for one full year.

But where does all this solar power actually come from? Well, keep in mind that the sun is a star, and like any other star, it's basically one big nuclear reactor. There are nuclear fusion reactions happening in the sun's core all the time, producing huge amounts of energy that radiate out into space in the form of light and heat. Large quantities of this solar radiation ultimately reach Earth's surface.

Solar power can be collected via a technology called photovoltaics, then converted into solar electricity that can be used to supply power to a home or a business. Solar energy currently represents a relatively small fragment of the global energy economy, yet it's gaining in popularity, largely thanks to the falling prices of solar panel installation, combined with a growing desire among homeowners to reduce their utility bills and their carbon footprints.

Using Solar Power

Now let's take a closer look at solar technologies and the process of harvesting and using energy from the sun.

We already mentioned photovoltaics, which represents the most common method of harvesting solar energy. This approach is generally used for small-scale applications, such as portable solar generators or residential solar systems. Another option, called solar thermal capture, is typically better suited to produce solar electricity on a larger scale.

Here's a quick breakdown of these two basic options for harvesting solar energy.

Harvesting Solar Energy With Photovoltaics

This is the method you're more likely to be familiar with, as it describes the way solar energy is harvested in residential settings. By installing solar energy systems made with photovoltaic cells, or PV cells, homeowners can collect energy from the sun, using solar panels positioned on their roofs that convert sunlight into energy. An inverter turns that solar energy into an electrical current, which can be used to power household systems, appliances and connected devices.

With some photovoltaic systems, any surplus electricity is funneled back into the power grid, resulting in a credit from the utility company; in turn, if the PV system does not create enough solar electricity to power the home, the homeowner may draw power from the main utility grid. By contrast, some PV systems come equipped with a solar panel battery bank, which means surplus energy can be stored and used at a later date.

There are a few types of solar panels, but most residential ones use what's known as the photovoltaic effect. This process allows them to convert raw solar power into usable energy. Here's a rough breakdown of how solar panels work:

  1. The sun's rays hit a semiconductor within a solar panel (usually made of silicon), which releases electrons. These electrons move through a conductor to produce an electric current.
  2. The current produced by these wires is known as direct current, or DC; your house requires alternating current, or AC electricity. A component known as a solar inverter turns the DC power into AC power.
  3. AC power is then fed into the primary circuit board, meaning it can power any of the outlets or connected appliances in the home. Surplus solar electricity may be stored in a battery to be used when the sun isn't shining directly on the panel.

This is a basic description of how solar electricity works in a residential setting, enabling homeowners to control their electricity generation. The benefit is that you can reduce or even eliminate your reliance on utility companies, and thus, your monthly utility bills. Even more impactful, it allows you to lessen your reliance on fossil fuels and municipal power plants, which cuts down on environmental pollution.

Harvesting Solar Energy With Solar Thermal

Another option for harvesting solar energy is to directly capture heat from the sun's radiation. The solar thermal method actually has a much broader range of uses than the photovoltaic process. With that said, it's not nearly as practical or as feasible to use the solar thermal method on a small scale, which is why residential solar systems use the PV method.

There are three main kinds of solar thermal energy used in industry:

  1. Low-temperature solar thermal energy is used to heat and cool the air.
  2. Mid-temperature is used specifically for heating water.
  3. High-temperature is used for generating electrical power.

So, to flesh those out a bit more: Low-temperature solar thermal methods are primarily used to heat or to cool the air, as a means of climate control like space heating or air conditioning. Mid-temperature solar thermal methods capture the sun's energy and transfer it to pipes, heating the water those pipes contain.

High-temperature solar thermal is used to generate electricity on a larger scale, such as in an electrical plant. This process actually revolves around a series of mirrors, which are positioned to catch the sunlight and reflect it onto a series of tubes. These tubes contain liquids that are effective in capturing and holding heat energy. This heated liquid is then used to turn water into steam, turning turbines to produce electrical power. You can understand why this complex system is not a feasible option for individual homes, but it represents a very promising renewable energy source for large-scale use.

Using Solar Energy in Your Home

Now that we've exhausted the solar energy definition, let's turn toward practical questions: Are solar panels worth it for your home? Let's go through some solar energy pros and cons.

Installing a Solar Power System Offers Immense Benefits

There are certainly a number of benefits to solar power, including:

  • Solar energy use can allow you to reduce your monthly electric bills and, in some cases, eliminate those bills completely. This produces big cost savings over time.
  • Solar power is a clean, renewable energy source, meaning you won't be contributing to direct pollution (unlike with oil or coal) and greenhouse gas emissions.
  • When you buy solar panels, there are a number of tax incentives and rebates available to offset startup costs, including some available at the federal level and some that are state-specific.
  • Most residential solar systems will produce electricity for 20 to 30 years and require very little maintenance.

There Can Also Be Drawbacks

Solar power boasts numerous advantages, but that doesn't mean it's perfect. Some of the most significant downsides include:

  • The initial cost of solar panels is fairly extensive, averaging out to around $13,000, and in some cases topping $20,000. Tax incentives and monthly utility savings can offset this cost, but even still, going solar always requires a big investment on the front end.
  • Some homes just aren't suited for solar. If you don't get enough exposure to the sun, then a home solar system may not work out.
  • If you live in an area where electricity is inexpensive, then the savings you get from a solar system will be comparatively small.

Is My Home Suitable for a Residential Solar System?

The best way to determine whether your home is a good fit for solar electricity is to contact one of the top solar companies in your area. A solar panel installation specialist can come take a look at your home and give you an individualized recommendation.

Solar energy is best suited for those who live in sunny areas; who have plenty of surface area on their roof; and who don't have to worry about shading from nearby trees, buildings or other obstructions.

Get a Free Quote for Professional Solar Installation

If you're interested in solar, it only takes 30 seconds to get a free, no-obligation quote. You could save up to $2,500 per year on utility bills and get a tax rebate all while reducing your carbon footprint. Fill out the form below to get started.

What to Look for in a Home Solar System

As you shop around for home solar systems, make sure to keep the following factors in mind:

  • The efficiency of your solar panels, or how much sunlight they actually turn into electricity (the most efficient solar panels convert over 20%).
  • The capacity of your solar battery.
  • Warranties and other protections for your home solar system.
  • The total number of panels you need to get the desired results.
  • The services offered by your solar installer (such as individual system design).

Are You Ready to Embrace Solar Power?

For anyone seeking a clean and efficient energy solution, solar electricity may be the best bet. If you're ready to continue your education, we recommend checking out some demos of specific solar panels, or else calling a local installer to get a solar energy quote.

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