Batteries are quickly becoming an essential component of household solar systems. A battery is essential if you wish to store electricity for usage when the sun isn't shining or during power disruptions. Off-grid solutions rely on batteries to power the home if the power grid fails.
Lithium-ion (Li-ion) batteries are now the most popular choice for solar batteries since they are extremely dependable and can be found in major battery storage devices like the Tesla Powerwall, Generac PWRcell, and LG Chem.
When looking for solar batteries for your home solar power system, there are several aspects to consider. Keep in mind the sort of battery you're searching for, as well as what you want to get out of your battery.
Lead acid batteries are the tried and reliable technology in the area of solar batteries.
Deep-cycle batteries have been used to store energy for a long time, dating back to the 1800s. And they've been allowed to stay because of their dependability.
Lead acid batteries are classified into two types: flooded lead acid batteries and sealed lead acid batteries.
Pros:
Lead acid batteries are the least expensive kind of energy storage, making them the most cost-effective. They are also trustworthy. Furthermore, because the technology has been around for a long time, it is simply disposed of and recycled.
Cons:
To function properly, flooded lead-acid batteries require ventilation and frequent maintenance, which increases the likelihood of the battery leaking.
Because flooded lead-acid batteries cannot be installed on their side, this restricts how they may be installed. They also have a low depth of discharge (DoD), which necessitates more frequent charging. Because of their modest depth of discharge, they have a shorter lifespan—between five and ten years.
Lithium-ion batteries are the newest additions to the energy storage family. As electric vehicle popularity grew, EV makers recognized lithium ion's potential as an energy storage option. They immediately rose to prominence as one of the most extensively used solar battery banks.
Pros:
Lithium-ion batteries practically never need to be maintained.
They also have a greater battery energy density than lead-acid batteries, which means they can store more energy in a smaller space.
They also have a longer life cycle or lifespan—most have at least a 10-year warranty. This extended lifespan is due to lithium-ion batteries' deeper depth of discharge, which allows you to use more of the energy contained inside the battery before it has to be recharged.
Cons:
One of the most significant downsides of lithium-ion batteries is their higher cost than other energy-storage technologies.
Furthermore, because of their chemistry, lithium-ion storage devices are more likely to catch fire owing to a phenomenon known as thermal runaway. However, if correctly fitted, the chances of your battery catching fire are almost none.
Ni-Cd batteries are not as extensively utilized as lead acid or lithium-ion batteries. They initially appeared in the late 1800s, but they were given a makeover in the 1980s that dramatically boosted the amount of energy they could store. They are popular in the aviation sector.
Pros:
The key feature of Ni-Cd batteries is their durability. They can also work at high temperatures. Furthermore, they do not require sophisticated battery management systems and are almost maintenance-free.
Cons:
The most significant drawback of Ni-Cd batteries is that cadmium is exceedingly poisonous. In fact, several nations prohibit the use of cadmium. This makes them difficult to dispose of. They are also susceptible to the memory effect, which reduces their capacity to keep a charge.
Flow batteries are a new technology in the energy storage industry.
They contain a water-based electrolyte liquid that flows between the battery's two distinct chambers, or tanks. When charged, chemical processes take place, allowing the energy to be stored and then expelled. These batteries are becoming increasingly popular.
Because of their bigger size, they are more costly than other battery kinds. The exorbitant price, along with their vast size, makes them difficult to adapt to household use. However, reflow produces a domestic flow battery known as ZCell.
Pros:
One of the finest features of flow batteries is their 100% depth of discharge. This implies that you may use all of the energy contained in the battery without endangering its health.
Because the liquid within the battery is also fire retardant, there is no chance of thermal runaway. Flow batteries have the greatest longevity of any battery on our list, lasting 30 years! Furthermore, they are low-maintenance.
Cons:
Unfortunately, flow batteries are substantially more costly than other kinds of solar batteries. They also have poor storage capacity when compared to other battery systems, so they must be huge to retain a significant quantity of energy.
They have very low charge and discharge rates, which implies they must be huge in order to be effective.
However, because of supply chain restrictions and growing lithium prices, many enterprises are turning to innovative battery technologies for solar energy storage. One battery technology is sodium ion, which uses a low-cost and abundant material: sodium.
Sodium-ion batteries are poised to replace lithium-ion batteries in the renewable energy storage space. Can sodium ion batteries be used for long-term applications? Let’s find out.
Sodium is used as a charge carrier in a sodium-ion battery. Because the internal structure of sodium-ion batteries is similar to that of lithium-ion batteries, they are frequently pitted against one another. Sodium-ion batteries, like lithium-ion, lead acid, and absorbent glass mat (AGM) batteries, are rechargeable.
The development of sodium-ion batteries dates back to the 1980s and has lately begun to speed up due to issues with scaling lithium-ion batteries, such as rising material costs and the need to obtain significant amounts of lithium to support battery production and demand.
There has been substantial study towards improving Na-ion battery cells, particularly the use of Prussian blue as a cathode material. The Na-ion battery pack may take on a variety of useable designs, from standard cylindrical cells to rectangular pouches. These different form factors make this battery type perfect for commercialization, allowing it to be utilized for energy storage, electric cars, and portable gadgets.
Sodium ion vs. NMC vs. LFP batteries
Sodium ion | NMC | LFP | |
Availability | Under development | Accessible | Accessible |
Cost | Cheapest | Cheaper | Most expensive |
Energy density | Lowest | Highest | Moderate |
Safety | Safest | Least safe | Safer than NMC |
Round-trip efficiency | 92% | 90-95% | 92-98% |
Efficiency and energy density
Since sodium-ion batteries of the group have the lowest energy densities, they are larger than lithium-ion batteries. Energy density is higher with NMC batteries.
Despite having the same capacity, a 10 kWh lithium-ion battery will fit more compactly within your home than a 10 kWh sodium-ion battery. If you don't have much room on your land, this may be a problem, but Na-ion batteries are still in development, so things could change in the future.
More than ninety percent of the round-trip efficiency is offered by each of the three battery technologies. This indicates that the batteries are efficient in reducing energy losses, enabling you to store more of the energy produced by your solar panels rather than having it lost throughout the storage process.
Batteries that have high round-trip efficiency can reliably run electronics and appliances for extended periods of time. Compared to NMC and Na-ion batteries, LFP batteries offer a slightly greater round-trip efficiency. The variations, meanwhile, are small and are only apparent in solar arrays that are installed on a big scale.
Safety
Sodium-ion solid-state batteries can work efficiently at high temperatures and are not flammable, making them safer than Li-ion batteries. Even though they are reliable, lithium batteries can catch fire if handled, charged, or stored incorrectly.
Cost
Battery technology acceptance is heavily influenced by cost; they increase the cost of a solar system installation by several thousand dollars. Due to its use of less expensive materials, sodium-ion batteries are anticipated to be less expensive than lithium-ion batteries.
Depending on the kind and capacity, lithium-ion batteries for solar energy storage generally cost between $7,000 and $14,000 before the federal solar tax credit.
Lithium and cobalt are used extensively in the production of lithium-ion batteries. Lithium prices are rising as a result of inflation, a surge in the demand for electric vehicles, and the need for residential energy storage. The unexpected increase in demand for the metal has resulted in a shortfall, which is expected to last for several more years. Nickel, cobalt, or lithium are not used in sodium-ion batteries.
The truth is, that the development of sodium-ion batteries is fueled by the difficulties in obtaining lithium. In order to meet the need for energy storage, many people think a new kind of battery should be introduced.
Availability
Although the majority are still in the prototype or demo release stages, certain sodium-ion batteries are still available for purchase. Purchasing sodium-ion batteries online is difficult and necessitates sending a formal request to the supplier.
On the other hand, several battery manufacturers throughout the world sell lithium-ion batteries for solar energy storage systems. These items are now the preferred battery technology among customers and leading brands or sellers. They are conveniently available online or via a nearby solar contractor.
Sodium-ion batteries are cutting-edge solutions for the rapidly expanding household solar market.
Many people see it as a means to scale energy storage since, unlike lithium-ion technology, it makes use of readily available and sustainable materials. Low manufacturing costs for sodium-ion batteries may help increase product adoption. However, the development and manufacture of this battery type are still in their early phases.
On paper, sodium-ion batteries have had several benefits over conventional lithium-ion and lead-acid batteries, notably in terms of sustainability. These traditional batteries, on the other hand, have a lengthy history and track record of dependable performance in real-world applications. This, in our opinion, is what matters and is severely lacking in sodium-ion batteries.
Sodium-ion batteries are being tested as a promising alternative to conventional solar batteries. If they prove to be long-term effects, they will make home solar panel installations easier—but only time will tell. You'll know it's time to get them when:
To date, sodium-ion batteries appear to be on the right route to acting as a future replacement for regular batteries; nevertheless, they may not be ideal for solar systems until further improved.