Solar Energy and Home Battery Systems
Solar energy systems have become one of the fastest-growing energy market segments in the U.S. Per the Solar Energy Industries Association (SEIA), the solar energy market doubled its size in 2016.
How does a solar-with-battery system work?
Consumers increased demand of solar energy has brought about the rise of another renewable technology: solar battery storage, that can store excess solar energy for later self-consumption (immediate use). Just a few years ago, the cost and challenge to integrate battery systems with a solar electric array just wasn’t cost effective or reliable.
But now many companies like LGChem RESU and Tesla Powerwall are developing and deploying batteries that can be installed with solar energy systems to create a very favorable financial savings.
Finding, designing, and installing these “solar-with-storage” systems for your home can be a daunting. Southface Solar & Electric can help.
Continue reading below to learn more about solar battery systems, and to find out which battery options might best fit your specific needs and wants.
You have energy storage choices
Off-Grid Solar/Battery :: On-Grid Solar/Battery :: Battery Back-up :: Battery Only
Solar with storage systems: Explained
To understand why someone like you would consider to install a solar-with-storage option, you first need to understand how a basic grid-tied (storage-less) solar PV system works.
The most commonly installed solar electric systems (synchronous systems) have solar panels, an inverter (string or micro), the structure (racking) to attach the equipment to your roof (unless ground mounted), and sometimes a monitoring system that tracks energy production. The solar panels then collect energy from the sun and sends that energy through the inverter(s) which Inverts it into a form that you can use to supply energy to your home to use.
Right now, most solar energy systems are interconnected to the Utility grid (or “grid-tied”). When your solar electric system produces more energy than you can self- consume, the excess energy is fed back into the utility grid. Conversely, in times of low system production like night time or bad weather when your home needs more energy than your solar energy system is producing, you can draw back power from the utility grid.
In many instances, you will receive a credit on your utility bill for the energy or Kilowatt Hours (kWh) you send onto the grid. While later, when you are using more energy than your system provides, you can apply these credits to reduce your utility bill.
How solar energy charges batteries
Solar-with-batteries works by accepting energy being produced by your solar panels and store it as DC energy for later use. In some situations, solar batteries utilize a charge controller to facilitate this. In other cases, the batteries have their own DC to AC inverter(s) or use a DC-DC Inverter.
When a solar battery is installed as an integrated part of your solar system, you are essentially choosing this method instead of sending kWh’s out onto the Utility grid, storing those excess kWh locally for later use when needed.
When your solar system is producing more energy than you self-consume, the excess energy is charging your battery. Once your energy needs exceed your solar systems production levels, the system then provides these kWh’s to your energy needs with the batteries. You will only send energy back to the utility grid when your batteries are fully charged and all your energy needs are met. If or when your batteries are not able to provide the energy you need, then you will rely on energy from the utility grid. We like to refer to this as the “Me First” approach.
Basically, this means that by using the solar-with-storage approach, you can store excess solar production onsite for later use at night. In addition, since the solar batteries store energy locally, they can offer short-term or long-term backup energy needs if there’s an electrical black-out or brown out in your area.
Energy storage used without solar
While batteries are synergistic when paired with a solar energy system, batteries can be a powerful and useful tool also without solar panels. The technology used in a solar-with-storage system, can stand on its own and be charged with energy from the grid to allow for backup power, or power arbitraging a buy-low-sell-high approach to reducing one’s energy consumption. (This method, while it sounds great, usually is not the best financial decision in most areas right now due to battery prices and cycle life). You could even forgo the grid charging and go with natural gas or diesel-powered generator charging. The options here are limitless.
Today a lot of people are talking about batteries; more importantly how to incorporate them into the home. Some think a simple plugin powered wall battery will eliminate that monthly utility bill. I wish it was that simple, but for most of us here in Arizona, it is a more complex process.
Should I install a solar battery system?
This question can be challenging. The true answer is a personal decision for anyone looking for a battery system. There are many reasons to install a solar-with-storage solution. The financial question is one of the most asked and the answer depends on whether you can save money and on how you get your energy now.
While battery technology is a very real and effective tool today in some cases, the promise of batteries can be out of reach due to a real misunderstanding of what battery limitations are. Battery Technology has and will continue to evolve quickly. But we still need to address some key issues to help you in deploying a battery system in your home and the check you would have to write for batteries tomorrow. The ideas presented here will help achieve your dream of integrating a home battery system faster than you might think.
If your energy source is through a utility company, the way they compensate you for your solar power might make it a great option or not. Most utilities currently offer net metering, which means you receive a credit on your electric bill for every kWh of electricity your solar panels send back to the grid. Then you reduce the amount of kWh’s you must pay for by the same amount on your bill. This is kWh to kWh (Full Rate). This sounds simple and is.
But, like here in Arizona, many utility companies are working out new rate Tariffs or creating completely different rate structures that modify or eliminate NET metering all together. This is done with lower kWh pricing and increasing power (Demand) charges. This ultimately reduces or eliminates the value of NET metering all together. In either of these cases this shift away from any NET metered billing usually helps to incentivize and makes battery-with-storage solutions look and respond financially favorable.
The reality you need to understand is for most Arizona homeowners today a solar-with-storage solution is more complex than one might think. Efficiency of your home’s structure, which appliances you purchase or use, the type of Air Conditioners you have, or sometimes — even more important — just the lifestyle you live. Basically, having a strong understanding of your “energy strategy” and how you use or not use that strategy is key to making your battery investment work and pay for itself.