SOLAR BATTERIES EXPLAINED
Until the ERCOT grid recently started failing, most Texans never gave much thought to the role solar batteries play in our lives - for our homes or the community at large. As the Lone Star State seeks greener energy solutions for the future, storing the sun's energy in solar batteries will bring ever-increasing stability and peace-of-mind to homeowners.
Solar batteries are a key component of residential energy independence and management. They ensure you are not left at the mercy of the power grid during the next outage or grid failure. Battery storage also allows consumers to draw from their batteries during peak usage hours when grid supplied electricity rates are highest.
First, explore the features and differences of the top 4 solar batteries for 2023 in the Comparison Chart above. Next, we will look at the different metrics used to evaluate these batteries.
Texas Top Solar Batteries 2023
Top 4 Solar Batteries
Solar Home Review has assembled a list of the best solar batteries from the top name brands available to Texas solar consumers.
| Battery | Pros | Cons |
|---|---|---|
| Enphase IQ
Best battery in class: most advanced |
|
|
|
Tesla Powerwall 2
best warranty |
|
|
|
Sonnen Eco
most versatile |
|
|
|
Sunpower SunVault
largest capacity |
|
|
| Enphase IQ Battery |
Best in Class: Most Advanced |
Pros |
|
Cons |
|
| Tesla Powerwall 2 Battery |
best warranty |
Pros |
|
Cons |
|
| Sonnen Eco Battery |
Most Versatile |
Pros |
|
Cons |
|
| Sunpower SunVault Battery |
largest capacity |
Pros |
|
Cons |
|
Homeowners may be eligible for a 30% tax credit when purchasing battery storage
We at Solar Home Review are happy to assist if you have questions about solar batteries, and which appliances are capable of being operated on a given battery configuration.
The Metrics We Used to Measure Top Battery Picks for 2023
Types of Solar Batteries
The chemistry used in solar batteries may differ from one manufacturer to another. One type of battery may be better suited for a specific application than one with different chemistry. Most common battery types available in 2023 fall into one of two broad categories:
Lead-acid Batteries vs. Lithium-ion Batteries
Aside from being constructed of chemically different materials, perhaps the most fundamental distinctions may be performance and price point. As a general statement, Lead acid batteries tend to be more economical, whereas Lithium-ion based batteries are more efficient and come with a higher price point.
Deep cycle Lead-acid batteries are not normally a first choice in residential grid-tied systems, however are a much more common choice in complete off-grid systems. These batteries are engineered to be larger and heavier than lithium batteries to withstand routinely draining the charge. Lead acid batteries require more time to recharge after discharging. Lead-acid batteries also have a shorter lifespan when compared to the lifespan of lithium based batteries, as well as require routine maintenance.
Lithium Batteries
A more popular option among Texas residential consumers is the quick charging, longer lasting Lithium based battery variations. These batteries are smaller and lighter when compared to lead-acid batteries.
Of the Lithium based variations; Lithium Nickel Manganese Cobalt Oxide (NMC) is the most common. NMC technology has been real world tested for many years. Compared to other lithium based batteries, NMC can be a very economical choice. The cobalt in NMC batteries reduces the likelihood of thermal runaway/fire. The Tesla Powerwall is a well-known Lithium Nickel Manganese Cobalt Oxide battery.
What is thermal runaway?
Thermal runaway is an uncontrolled thermal reaction that can take place in solar batteries. Luckily, it is extremely rare, as residential solar batteries are required to undergo strenuous testing to ensure it does not occur. Further preventative measures include component arrangement, protective outer casing around the battery cells, and enhanced internal cooling. Together, they all contribute toward diminishing the already minimal risk of an uncontrolled thermal reaction.
Lithium Iron Phosphate (LFP)
Lithium Iron Phosphate or LFP batteries rely on a recently devised chemical formulation that allows for more efficient energy retention. LFP batteries generally have a higher power rating with a lower energy density rating. The new phosphate chemistry, however, comes at a higher price point.
Iron (Fe) in LFP batteries results in reduced heat output, so effectively that most LFP batteries don’t require the same robust ventilation and/or cooling as NMC batteries. Cooler operating temperatures make LFP batteries a great option for a wider range of mounting locations – including indoors.
Batteries with LFP chemistry provide longer life of service over other lithium-based batteries. Sonnen and Enphase both use LFP chemistry.
Compare your Solar Battery Options Today with Solar Home Review
If you are considering a residential solar battery for your home, start by speaking with a certified solar professional. Solid professional advice combined with electrical expertise and in-depth knowledge of the latest industry best practices can turn an involved process into an enjoyable experience.
Solar Home Reviews will see you get the best information possible about residential solar storage options. If you want to learn more about solar-plus-storage options near you, we are happy to help. Simply complete the quick questionnaire below, so we can provide specific answers to your questions about the solar products you’re interested in.
AC-Coupling vs DC-Coupling
The solar panels on your roof (or ground mounted array) create direct current (DC) electricity that needs to be converted into alternating current (AC) electricity for use in our homes. A system that is AC-coupled makes this DC to AC conversion at the inverter, then reconverts it back to DC for storage. When the battery is discharged, the electricity is converted yet again to AC. In contrast, in a DC-coupled system, the current conversion from DC to AC only needs to happen once.
AC-coupled batteries lose a bit of their efficiency in the conversion and reconversion process. In addition to higher efficiency ratings, DC-coupled batteries are able to recharge from solar panels – even when the grid is down. DC-coupled systems are certainly worth consideration if you are installing an entirely new system. Note, however, that DC coupled systems are more complicated to install and may require additional installation costs. Conversely, AC-coupled systems are easier to install, as well as easy to add to pre-existing residential solar systems.
Battery Capacity
Battery capacity is the measurement of a solar battery's electrical storage. It is expressed in kilowatt-hours (kWh). The term “usable capacity” is a measurement of the amount of energy the battery has available for immediate use. It is also expressed in kilowatt-hours (kWh). Battery function requires some energy, so the “usable capacity” of a battery is lower than the overall “battery capacity.”
Proper pairing of the size of your battery’s capacity in relation to the amount of electricity produced by your system is an important consideration. Most solar arrays produce in excess of your daytime electricity consumption. This allows you to store unused electricity for later use. If your battery is undersized, you may be disappointed in the event of a grid failure. If your solar battery is too small, you may not be able to use some electric appliances. If your battery capacity far exceeds your storage needs, it may be too big for your system, and you will not recoup the extra money you invested in the battery.
Depth of Discharge
Depth of discharge (DoD) is the ratio between a battery's full capacity and its usable capacity. It is expressed as a percentage. Lead Acid batteries hoover around 50%DoD, while lithium ion-based batteries range between 80% and over 99%. Fully discharging a battery may shorten its overall service life. Because of this, many batteries are engineered with a limited DoD, so they discharge at a lower percentage of the batteries full capacity.
Power Rating
“Power rating” is the measurement of the amount of electricity a battery can discharge over a given period. It is expressed in kilowatts (kW). Power ratings are measured in continuous power and peak power.
- Continuous power: indicates how much electricity a battery can produce in a given time period. Continuous power is an important metric in determining how long your home can be powered by a specific battery.
- Peak power as the term implies, peak power is the measurement of the maximum, instantly available power a battery can produce.
A low-capacity battery with a high peak power rating can deliver short bursts of electricity, but is unsuitable for power production over extended time periods. Alternatively, high-capacity batteries with a low peak power rating provide electricity for less demanding devices for extended periods of time.
Round-trip Efficiency
Round-trip efficiency measures the amount of available electricity after the loss experienced during the charging process. It is expressed as a percentage. A higher Round Trip Efficiency percentage represents a higher amount of energy retained after charging.
Warranty
The industry standard for solar batteries warranties is ten years. Some manufacturers add ‘throughput clauses’ or ‘cycle limitation clauses’ that could end the warranty early. Be aware that not all battery warranties are the same.
Look for batteries with no limitations on cycle count or higher cycle count thresholds. Most warranties will guarantee the battery will retain a certain percentage (60% at 10 years is industry standard) of its original new capacity by the end-of-warranty.
Now that you are familiar with some of the metrics we use to evaluate solar batteries, let’s take a closer look at some popular batteries Texas solar shoppers will likely come across in 2023.