What's the difference between grid-tie and off-grid solar?

When it comes to solar, there can be some confusion about what it means to have a system that is “off-grid” vs. a system that is “grid-tied.” Our goal is to simplify the differences for you and help you become a more educated homeowner when it comes to solar. If you’re interested, we can also connect you with one of our sales associates who can show you how to become a producer of renewable energy. Let’s get started.

Grid-tied solar and why most people have it

Currently, the majority of solar energy systems installed in U.S. homes are connected to an electrical grid. If you’re not already aware, these grids are primarily owned by utility companies such as PG&E or ConEdison. By connecting your solar energy system to a utility grid, you’re setting up a “grid-tied” system.

When tied to an electrical grid, the homeowner can get electricity from their solar energy system or utility grid. If your solar energy system is sized correctly, during the day, when the sun is shining, you can rely on solar for your energy needs. When the sun goes down, the electrical grid takes over, so you can access energy to power your home. A potential benefit of this is that, in some areas, power rates can go down at night, which means you could be paying less for the energy you use from the grid.

The critical thing here is energy access. To ensure you have enough energy at night, off-grid solar homeowners may have to closely monitor their energy usage during the day. With grid-tied solar, this isn’t the case because the constant access to the grid means that you’ll still have energy when the sun goes down. The only exception to this is when the power goes out, and you can always check our solar batteries for potential options during those times.

Now, you might be saying, “That’s great, but doesn’t that mean that my solar energy system will go offline if the power goes out?

Excellent question. Yes, it does. Because your solar energy system is tied to the grid, when the grid goes down, your solar system will too. As a safety precaution, grid-tied solar energy systems are intentionally designed to shut off during a power outage. Shutting off the power protects you, your neighbors, and the utility workers from potential accidents.

If you’re concerned about power outages in your area, we encourage you to check out our solar batteries for help.

What happens if my solar system produces more power than I can use?

Glad you asked. Many utilities have agreements set up with customers to credit them for the excess power produced. This process is known as net metering. Think of it as a basic math problem:

Energy produced - energy consumed = net energy.

The “net energy” is the amount that the utility company will credit you. The credit amount can depend on things like the requirements set by your utility company, the amount of energy you consume/produce, the net metering rates in your area, etc. Some utilities pay customers retail rates, some pay wholesale rates, and some do not pay for excess solar production. When you speak with your solar consultant, be sure to ask about the program(s) available to you in your area and based on your utility company.

Off-grid solar and why it’s less popular

Given that we just covered what a grid-tied system is, you can probably deduce what an off-grid system is. You guessed it—it’s a solar energy system that is not connected to a utility grid. Here’s a rough idea of how it works: a homeowner may purchase a solar energy system from a solar manufacturer, connect it to their electrical system themselves (or by paying someone to do it for them), and turns it on when it’s connected. Once that’s done, the homeowner should start producing and consuming energy without any involvement from the utility company.

That’s probably the most significant benefit to off-grid homeowners. Not having to pay a utility bill ever is a huge money saver. It also means that you could have access to energy during more difficult times, like when the power goes out or during the rapture.

It’s also a good idea for off-grid homeowners to ensure that their home is energy efficient. Since there is no utility grid to pull energy from when your solar panels are not producing energy, you may want to invest in a back-up energy source. Back-up energy comes in the form of a solar battery or generator. With a solar battery, instead of the excess energy being sent to the utility grid, it’s sent to a battery and stored for later use. When your solar panels are no longer producing enough energy to keep up with consumption, the battery will make up the difference.

Another thing to keep in mind with an off-grid solar energy system is that you may have to monitor your energy usage much more closely. Simple things like keeping your cell phone charger plugged in overnight or falling asleep with the tv on may cause a big dent in your energy usage. This is the part that tends to deter other energy users. Off-grid solar, though more environmentally beneficial and probably much cheaper, requires closer monitoring of how you use your energy. It’s more of a lifestyle change that grid-tied solar homeowners don’t need to focus on as much. Then again, maybe a lifestyle change for the benefit of the environment isn’t a half-bad idea. Just say’n.

Pros and cons of grid-tied solar

Pros

• Potentially less expensive because back-up equipment isn't a necessity for the system to operate.
• Potential to receive credits for sending energy back to the grid.
• Flexibility to rely on the grid when the sun goes down.
• No need to worry about offsetting your entire energy consumption.

Cons

• Cannot function when the utility grid goes down, keeping solar energy system from back-feeding to the utility grid and creating a hazard.
• Ever-changing and unpredictable utility rates.

Pros and cons of off-grid solar

Pros

• Energy independence from the utility company.
• Rates won’t exist because you’re not tied to the utility grid.

Cons

• High down payment cost usually requires payment of all solar equipmentupfront as opposed to grid-tied solar payment options.
• May require more solar panels and battery storage to keep up with total household consumption.
• May have to adjust lifestyle to reduce energy consumption, such carefully monitoring things like how often you use your air conditioner.

The hybrid approach and what it offers

While you may not be interested in going off-grid, many homeowners are now opting for a solar battery in conjunction with a grid-tied system, or a “hybrid” of the two options. A hybrid solution can provide some independence from the utility company while still giving you access to the utility grid for extra peace of mind.

A battery can provide you with flexibility, which means you may be in a position to capitalize on Time of Use rates. By harnessing the benefits of a solar battery (and depending on the requirements set by your utility company), some solar homeowners can charge their solar battery during the day at a lower cost per kilowatt-hour. Once charged, they can use the power from the solar battery in the evening when the cost per kilowatt-hour is at its peak, thus potentially saving significant money over the life of the battery.

A battery can also offer you something called a “demand response” option. When there is a lot of stress on the grid during peak times, some utilities may provide incentives to solar homeowners to send energy back into the utility grid. In exchange for doing this, you may be compensated in the form of a statement credit on your bill. This is also based on the area in which you live and the requirements set by your utility company. That being said, it’s still a way to offset your total energy consumption and potentially benefit you and mother earth.

Choosing the option that’s best for you

As discussed, there are three options available to you as a solar energy homeowner: grid-tied, off-grid, or a hybrid of each. Depending on your needs as a homeowner, it’ll be up to you to choose which option appeals to you more. We recommend talking to or researching other grid-tied and off-grid solar homeowners in your area to see how they feel about their setup and what they suggest. It’ll also depend on your utility company, your current rates, and the things you want to accomplish with your solar energy system. If you’re interested, feel free to reach out and speak with one of our solar consultants who will review your energy usage and walk you through a grid-tied system that may work for you.