The surplus use energy produced by the solar panel is an electrochemical device that stores DC electricity in the chemical energy position.Batteries are divided into types according to the types of metal used such as lead acid, nickel cadmium, nickel iron.Today, the most widely used battery type are lead-acid accumulators.
The types of batteries most commonly used in Solar Energy Systems are as follows:
1-Deep Cycle GEL VRLA Batteries 2-OPzV Series – Tubular Gel VRLA Batteries 3-OPzS Series-Flooded Tubular VRLA Batteries 4-DC Series – AGM Deep Cycle VRLA Batteries 5-Lead Carbon – Lead Carbon Batteries 6-Lithium and Lithium Ion Batteries
1-Deep Cycle Gel VRLA Batteries
- Voltage class: 2V/6V/12V
- Capacity range: 26Ah~3000Ah
- Designed for frequent cyclic charge and discharge applications under extreme environment. Suitable for solar & wind energy, UPS, telecom systems, electric power systems, control systems, golf cars, etc.
Technical Features :
DG (Deep Cycle GEL)series is pure GEL battery with 15~20 years floating design life, it is ideal for standby or frequent cyclic discharge applications under extreme environments.By using strong grids, high purity lead and patented Gel electrolyte, the DGseries offers excellent recovery after deep discharge under frequent cyclicdischarge use, and can deliver 400 cycles at 100% DOD. Suitable for solar,CATV, marine, RV and deep discharge UPS, communication and telecommunication , etc.
2- OPzV Series-Tubular Gel VRLA Batteries
- Voltage class: 12V/2V
- Capacity range: 60Ah~3000Ah
- Tubular plates with Gel electrolyte provides super strong lifetime operation temperature. Application: solar & wind energy, UPS, control systems, telecom systems, electric power systems, emergency lighting, etc.
Technical Features :
OPzV series is a Valve Regulated Lead Acid battery that adopts immobilized GEL and Tubular Plate technology to offer high reliability and performance. The Battery is designed and manufactured according to DIN standards and with die-casting positive grid and patent formula of active material. OPzV series exceeds DIN standard values with more than 20 years floating design life at 25℃ and is even more suitable for cyclic use under extreme operating conditions.
3-OPzS Series-Flooded Tubular VRLA Batteries
- Voltage class: 2V
- Capacity range: 250Ah~3000Ah
- Flooded electrolyte design
- High charge acceptance performance
- Application: solar & wind energy, UPS, traction forklifts, traction electric vehicles, control systems, telecom systems, electric power systems, etc.
Technical Features :
OPzS Series are flooded Lead Acid battery that adopts Tubular Plate technology to offer high reliability and performance. The Battery is designed suitable for cyclic use(solar/wind energy, traction etc) under extreme operating conditions positive spine and patent formula of active material. OPzS series exceeds DIN40736-2/IEC60896-11 standard values with more than 20 years floating design life at 25℃ and is even more and manufactured according to DIN40736-2/IEC60896-11 standards and with die-casting.
4- DC Series – AGM Deep Cycle VRLA Batteries
- Voltage class: 2V/6V/12V
- Capacity range: 26Ah~3000Ah
- Superior deep cycle design suitable for solar & wind energy, UPS, telecom systems, electric power systems, control systems, golf cars, etc.
Technical Features :
AGM or Absorbent Glass Mat is an advanced lead-acid battery that provides superior power to support the higher electrical demands of today’s vehicles and start-stop applications. AGM batteries are extremely resistant to vibration, are totally sealed, nonspillable and maintenance-free.
DC (AGM Deep Cycle) series is specially designed for frequent cyclic discharge. By using strong grids and specially designed active material, the DC series battery offers 30% more cyclic life than the standby series. It is suitable for UPS, solar & wind energy, telecom system, electric power system, electric vehicles, golf cars, etc.
5- Lead Carbon – Lead Carbon Batteries
- Voltage class: 2V/12V Capacity range: 75Ah~3000Ah
- Fast charging, more energy efficiency
- Suitable for PSOC
- Application: Solar & wind energy storage systems, home energy storage systems, ESS systems, etc.
Technical Features :
DC-C series is lead carbon battery and carbon material with high capacitance and high conductance is added into the negative electrode, combining the advantages of lead acid batteries and super capacitors. Lead carbon battery provides not only high energy density, but also high power, rapid charge and discharge, longer cycle life. It is suitable for solar and wind renewable energy, etc.
Lead carbon batteries are found to be of lithium power but are very affordable in price. One of the most important problems that can occur over time in standard lead acid batteries is the sulfation of the electrolyte in the battery. This directly affects the health of the battery. In lead carbon batteries, by adding carbon to the negative electrode, the battery life is directly increased by preventing sulfation.
Advantages of Lead Carbon batteries versus Lithium batteries and LeadAcid: • No BMS (Battery Management System) is needed to prevent over-charging and under-charging on a per cell basis. • No thermal run-away risk of individual cells overheating, exploding, and burning. • Much greater Kw storage capacity per dollar compared with lithium. Approximately twice the storage capacity, or about half the price for the same Kw capacity. • Easy to carry modular system where each battery can be carried and put in place, without needing any lifting equipment. • Suitable for On-Grid Hybrid and Off-Grid systems due to high discharge amperage capacity. • No Cooling fans/system needed for lead-carbon batteries. • Much higher energy density and longer life in the same size (or smaller) package compared with existing AGM / GEL and Flooded Lead Acid Batteries. • No harmful and toxic gases coming off lead-carbon batteries.
The hybrid technology, which can quickly output and input charge during acceleration and braking, is particularly suited to the “stop and start” system of micro-hybrids. Lead-carbon battery can improve the power of the original lead-acid battery and prolong its service life.
Compairing Lead Carbon Batteries With Lead Acid Batteries ,Lead Carbon batteries are fast charging and improve the charging speed 8 times faster ; The discharge power is increased by 3 times. Third, the cycle life is increased to 6 times, the cycle charge times up to 2000 times; Fourth, the cost performance is high than the price of lead-acid battery has improved, but the life of recycling greatly improved; Fifth, the use of safe and stable, can be widely used in a variety of new energy and energy saving areas. In addition, lead-carbon batteries also play to the specific energy advantages of lead-acid batteries, and have very good charging and discharging performance – 90 minutes can be fully charged (lead-acid batteries if this charge, discharge, life is less than 30 times). In addition, the addition of carbon (graphene) prevents the negative electrode from being sulfurated, which improves one of the factors of battery failure.
1. The positive and negative lead paste adopts unique formula and optimized curing process. The positive active material has a strong anti-softening ability, good deep cycle life and high utilization rate of active material. The negative lead paste has a strong resistance to vulcanization, low capacity attenuation and good start-up performance at low temperature.
2. Positive electrode grid adopts new special alloy and reasonable structure design, with good corrosion resistance, reasonable current distribution, close combination with the active material, high current performance and strong charging acceptance ability.
3, the use of new electrolyte additives, the battery hydrogen, oxygen overpotential, the battery is not easy to lose water
4, when the battery in frequent instantaneous large current charge and discharge work, mainly by the carbon material with capacitive characteristics to release or receive current, inhibit the lead-acid battery “negative sulfuric acid”, effectively extend the battery life;
5. When the battery is operated with a long time and a small current, it is mainly operated by the negative electrode of sponge lead, which continuously provides energy;
6. The high carbon content of the lead-carbon super composite electrode makes the electrode have better low-temperature start-up ability, charging and receiving the ability and high-current charge-discharge performance than the traditional lead-acid battery.
6- Lithium and Lithium Ion Batteries
Batteries used in home energy storage typically are made with one of three chemical compositions: lead acid, lithium ion, and saltwater. In most cases, lithium ion batteries are the best option for a solar panel system, though other battery types can be more affordable.
Lithium batteries are a newer technology that hit the market in the 1970s. They are common in laptops and cellphones, but lately they have become more popular in the renewable energy space. Lithium batteries are more expensive, but there are several benefits to justify the higher price tag:
- Longer lifespan
- No maintenance
- More efficient power usage
- More usable storage capacity (deeper discharges)
- No off-gassing/ventilation
How to choose the best battery for a solar energy system
There are certain specifications you should use when evaluating your solar battery options, such as how long the solar battery will last or how much power it can provide. Below, learn about all of the criteria that you should use to compare your home energy storage options, as well as the different types of solar batteries.
How to compare your solar storage options
As you consider your solar-plus-storage options, you’ll come across a lot of complicated product specifications. The most important ones to use during your evaluation are the battery’s capacity & power ratings, depth of discharge (DoD), round-trip efficiency, warranty, and manufacturer.
Capacity & power
Capacity is the total amount of electricity that a solar battery can store, measured in kilowatt-hours (kWh). Most home solar batteries are designed to be “stackable,” which means that you can include multiple batteries with your solar-plus-storage system to get extra capacity.
While capacity tells you how big your battery is, it doesn’t tell you how much electricity a battery can provide at a given moment. To get the full picture, you also need to consider the battery’s power rating. In the context of solar batteries, a power rating is the amount of electricity that a battery can deliver at one time. It is measured in kilowatts (kW).
A battery with a high capacity and a low power rating would deliver a low amount of electricity (enough to run a few crucial appliances) for a long time. A battery with low capacity and a high power rating could run your entire home, but only for a few hours.
Depth of discharge (DoD)
Most solar batteries need to retain some charge at all times due to their chemical composition. If you use 100 percent of a battery’s charge, its useful life will be significantly shortened.
The depth of discharge (DoD) of a battery refers to the amount of a battery’s capacity that has been used. Most manufacturers will specify a maximum DoD for optimal performance. For example, if a 10 kWh battery has a DoD of 90 percent, you shouldn’t use more than 9 kWh of the battery before recharging it. Generally speaking, a higher DoD means you will be able to utilize more of your battery’s capacity.
Round-trip efficiency
A battery’s round-trip efficiency represents the amount of energy that can be used as a percentage of the amount of energy that it took to store it. For example, if you feed five kWh of electricity into your battery and can only get four kWh of useful electricity back, the battery has 80 percent round-trip efficiency (4 kWh / 5 kWh = 80%). Generally speaking, a higher round-trip efficiency means you will get more economic value out of your battery.
Battery life & warranty
For most uses of home energy storage, your battery will “cycle” (charge and drain) daily. The battery’s ability to hold a charge will gradually decrease the more you use it. In this way, solar batteries are like the battery in your cell phone – you charge your phone each night to use it during the day, and as your phone gets older you’ll start to notice that the battery isn’t holding as much of a charge as it did when it was new. For example, a battery might be warrantied for 5,000 cycles or 10 years at 70 percent of its original capacity. This means that at the end of the warranty, the battery will have lost no more than 30 percent of its original ability to store energy.
Your solar battery will have a warranty that guarantees a certain number of cycles and/or years of useful life. Because battery performance naturally degrades over time, most manufacturers will also guarantee that the battery keeps a certain amount of its capacity over the course of the warranty. Therefore, the simple answer to the question “how long will my solar battery last?” is that it depends on the brand of battery you buy and and how much capacity it will lose over time.
Manufacturer
Many different types of organizations are developing and manufacturing solar battery products, from automotive companies to tech startups. While a major automotive company entering the energy storage market likely has a longer history of product manufacturing, they may not offer the most revolutionary technology. By contrast, a tech startup might have a brand-new high-performing technology, but less of a track record to prove the battery’s long-term functionality.
Whether you choose a battery manufactured by a cutting-edge startup or a manufacturer with a long history depends on your priorities. Evaluating the warranties associated with each product can give you additional guidance as you make your decision.
How long do solar batteries last?
There are two ways to answer this question and the first is to determine how long a solar battery can power your home. In many cases, a fully charged battery can run your home overnight when your solar panels are not producing energy. To make a more exact calculation, you’ll need to know a few variables, including how much energy your household consumes in a given day, what the capacity and power rating is for your solar battery and whether or not you are connected to the electric grid.
For the sake of a simple example, we’ll determine the size of a battery needed to provide an adequate solar plus storage solution with national average data from the U.S. Energy Information Administration. The average U.S. household will use roughly 30 kilowatt-hours (kWh) of energy per day and a typical solar battery can deliver some 10 kWh of capacity. Thus a very simple answer would be, if you purchased three solar batteries, you could run your home for an entire day with nothing but battery support.
In reality, the answer is more complicated than that. You will also be generating power with your solar panel system during the day which will offer strong power for some 6-7 hours of the day during peak sunlight hours. On the other end, most batteries cannot run at maximum capacity and generally peak at a 90% DoD (as explained above). As a result, your 10 kWh battery likely has a useful capacity of 9 kWh.
Ultimately, if you are pairing your battery with a solar PV array, one or two batteries can provide sufficient power during nighttime when your panels are not producing. However, without a renewable energy solution, you may need 3 batteries or more to power your entire home for 24 hours. Additionally, if you are installing home energy storage in order to disconnect from the electric grid, you should install a few days’ worth of backup power to account for days where you might have cloudy weather.
Solar battery lifespan
The general range for a solar battery’s useful lifespan is between 5 and 15 years. If you install a solar battery today, you will likely need to replace it at least once to match the 25 to 30 year lifespan of your PV system. However, just as the lifespan of solar panels has increased significantly in the past decade, it is expected that solar batteries will follow suit as the market for energy storage solutions grows.
Proper maintenance can also have a significant effect on your solar battery’s lifespan. Solar batteries are significantly impacted by temperature, so protecting your battery from freezing or sweltering temperatures can increase its useful life. When a PV battery drops below 30° F, it will require more voltage to reach maximum charge; when that same battery rises above the 90° F threshold, it will become overheated and require a reduction in charge. To solve this problem, many leading battery manufacturers, like Tesla, provide temperature moderation as a feature. However, if the battery that you buy does not, you will need to consider other solutions like earth-sheltered enclosures. Quality maintenance efforts can definitely impact how long your solar battery will last.
What are the best batteries for solar?
Batteries used in home energy storage typically are made with one of three chemical compositions: lead acid, lithium ion, and saltwater. In most cases, lithium ion batteries are the best option for a solar panel system, though other battery types can be more affordable.
- Lead acidLead acid batteries are a tested technology that has been used in off-grid energy systems for decades. While they have a relatively short life and lower DoD than other battery types, they are also one of the least expensive options currently on the market in the home energy storage sector. For homeowners who want to go off the grid and need to install lots of energy storage, lead acid can be a good option.
- Lithium ionThe majority of new home energy storage technologies, such as the , use some form of lithium ion chemical composition. Lithium ion batteries are lighter and more compact than lead acid batteries. They also have a higher DoD and longer lifespan when compared to lead acid batteries. However, lithium ion batteries are more expensive than their lead acid counterparts.
- SaltwaterA newcomer in the home energy storage industry is the saltwater battery. Unlike other home energy storage options, saltwater batteries don’t contain heavy metals, relying instead on saltwater electrolytes. While batteries that use heavy metals, including lead acid and lithium ion batteries, need to be disposed of with special processes, a saltwater battery can be easily recycled. However, as a new technology, saltwater batteries are relatively untested, and the one company that makes solar batteries for home use (Aquion) filed for bankruptcy in 2017.
