Solar Battery Backup Power Systems
Without a battery you must use net metering or distributed generation with the electrical grid. In an outage it is a rule that to keep the grid safe the solar must shut off at inverter and panel level. Batteries allow your system to stay on in an outage creating a microgrid. This microgrid can include powering only essential loads or powering your entire home in an outage. We also occasionally suggest a generator for clients with easy access to natural gas. Expectations are so very important with batteries and that is where we excel. Letting you know how it will work and what it can cover. In some cases batteries can even increase the return on savings so always good to at least explore the option. We do batteries on about half of our installed projects.
Always Have Power
You’ll always have power when you add solar to your home. During the day, when the sun is shining, you’ll have enough power to run your home. However, at night and times when the weather is cloudy, you’ll need assistance from the grid. Typically, net-metering allows you to generate solar energy during the day and sell extra energy back into the grid. The company, in most cases, allows you to credit that towards the energy your home uses at night. Essentially the idea is for these two to cancel each other out and eliminate your energy bill completely. However, there may be times when service is interrupted or a storm rolls in and you don’t generate as much energy.
Here’s where Texas Solar Professional Back-up Power Systems come in.
These systems utilize specialized solar batteries to store energy for when you need it. During the day, you’ll be generating the most energy. Most times, the kids are at school, the adults will be working or running errands, and energy usage will be less. While some of this can go back into the grid, you can also store some in a solar battery to offset your usage at night. With enough battery power you can run your home at night or during those bad weather days without reliance on the grid, though the battery storage may be costly. You can also use a backup power system to run your essential appliances, such as your refrigerator or possibly your air conditioning unit, when the power from the grid goes out. Naturally you’ll still be connected to the grid, and be able to still utilize electricity, but these systems allow you to cut some costs and benefit you in the long run.
How Back-up Power Systems Works
This section will give you a brief overview of Back-up Power Systems for solar installation. First, it’ll go over how a solar setup typically works and what net-metering is. Next, it’ll go over how we determine your ideal storage setup. Last, we’ll help you get an idea of how we size your solar battery system and how much battery storage you may need. A Back-up Power System can add additional costs to your project. But let’s look at some of the details of such a system to allow you to determine if it’s right for you. Our professional solar panel team is always ready to help you with your needs and answer any questions you may have.
First, let’s talk about net-metering.
Determining Your Ideal Storage Setup
There’s no easy all-inclusive answer that fits all and all homes. It depends on your energy storage goals, what you want, and what your budget is. You may want to be able to run essential loads, such as your appliances, lighting, and Wi-Fi. You may want to backup your entire home. Some utility companies may not allow net-metering, so you may want to run your home at night when the sun isn’t shining. All of these situations are based on your needs and what’s best for you. Don’t worry, though, we’ll help you determine what’s ideal for you and what makes the best sense financially and practically.
Adding one or more batteries can add substantial costs to the project, so it’s important to figure out what your storage goals are and what loads you deem essential.
The average home uses 15 kilowatt-hours (kWh) of electricity per day. Here’s an important read on the difference between kW and a kWh, as there is a difference. Also, keep in mind that if your home has a large air conditioner or pool pump, you’ll use a lot more energy than 15 kWh.
Let’s move onto battery sizing.
Battery sizes are expressed in kWh. So for this average home, will it need 15 kWh of batteries to power it? In the case of a complete power outage, yes. However, on a typical day, you won’t be home during the day. An average home uses 30% of its power during the day when the sun is up and the solar panels are producing electricity, the other 70% is used at night. These numbers equal roughly 4.5 kWh of daytime usage and 10.5 kWh of nighttime usage. Without a battery system you’d have to buy that 10.5 kWh from the utility company (If the company allows for net-metering, then your costs will be offset by the solar you generate during the day). With a battery system, you’ll draw that power from the battery so that means you’ll need a 10.5 kWh battery to power your home at night. Obviously, you’ll use less or more power depending on the day, but it all depends on your needs and what you’d like.
While this may be confusing, Texas Solar Professional is here to help you out. We can check consumption numbers and allow you to plan accordingly. Back-up power systems are great if your situation allows. They provide more self-reliance and avoid not being able to use your essential appliances in the case of a major power outage.
Typical System Layouts
Here’s how some of those systems look. Notice that there are Whole Home Backups or Partial Home Backups. Whole Home Backups run your whole home off the backup system. While Partial Home Backups only run those essential parts of your home, say your refrigerator, lighting, and Wi-Fi.
With this battery back up option we will put in a sub panel off of your main electrical panel. We move the essential loads over to the sub panel. This would include 120 loads (meaning not your AC, heat pumps, or pool pumps). We install an automatic transfer switch to comply with the regulations of the utility company. In an outage the ATS islands off the sub panel and the system provides the microgrid with power. The essential loads will be fed by the panels and battery during the day and just the battery at night. Choosing the battery type and loads are something we discuss in the consultation.
Whole Home Battery
With this set up we cover the whole main electrical panel. 240 loads and 120 loads. We often like to add a load shedding/controlling option. So that in an outage you can control the biggest loads and that way your battery system will last longer for less overall cost. The battery systems we use switch from grid outage to power in milliseconds. You will have an app to monitor and control your battery. Depending on the utility this can be a great option to keep your power inside your own microgrid and not send it back into the grid.