What Is A Solar Battery?

Solar Battery Systems

A solar battery system is a storage device for energy generated by a solar photovoltaic (PV) system. These panels gather and absorb solar energy and convert it to electricity, then transmitted to your home via the inverter. The battery is an additional critical component that allows you to store energy generated by your panels and use it later, such as when the solar panels are no longer producing electricity in the evening.

However, if you have an off-grid system in your house or office, your solar PV system is interconnected to the power grid. This makes it possible to continue getting power even if your panels are not producing enough to satisfy your needs. When your solar system makes more power than you consume, the excess energy is delivered back to the grid, which is a process known as net-metering.

You will receive a credit on the next electricity bill if this occurs, reducing the amount you have to pay. In this post, you will learn about solar battery storage, why solar batteries are crucial, the types, and how to effectively take care of them to ensure optimal power storage.

How Does Solar Battery Storage Function?

Excess energy from your solar PV system is stored in the battery. This means that any extra energy is stored in the battery and is available for use when your solar panels are not making enough electricity. Home batteries in a solar power system store electrical energy, usually generated by a renewable energy supply, such as rooftop solar panels.

However, a home battery can also be charged using grid electricity. The energy is retained in your battery and can be used to power domestic appliances or other power components in your house at a later time. While the sun is shining, solar generation may be able to meet part of or all energy needs in a standard house with solar panels.

As mentioned earlier, the solar energy that is not used is outsourced to the grid. Shortages are filled by obtaining electricity from the grid, which is most commonly done in the early morning, evening, overnight, or during overcast weather. The surplus solar energy not consumed at home during the day can be used to charge the battery, provided you have battery storage for an existing rooftop solar system.

Storage systems on the market

Several energy storage systems are on the market with varying capabilities and performance levels. Some solar batteries can be charged using grid electricity at off-peak times (typically night-time) when electricity is more inexpensive than during the day. When energy demand exceeds that which is generated by the solar panels, the energy saved in the solar battery system is then utilised.

Before importing any energy from the grid, your battery's stored energy can power domestic appliances. When the stored energy runs out, you will use grid power to meet your household's energy needs until solar generation becomes available the following day.‍

Note: Batteries are not required to operate a simple grid-connected solar system. When you think about it, the grid acts as an endlessly large battery unless there is an outage.‍

The right battery storage

The average Australian home consumes a lot of electricity. The peak draw might easily be around 7 to 8kW if, for instance, your air conditioner or kitchen oven is on or when someone starts the kettle for a nice cup of tea. All except the most extensive and costly battery packs will be instantly overloaded.‍‍

The Tesla Powerwall, for example, has a peak output of 7 kW but only 5 kW constant. Even though it does not overcharge, the battery can soon be depleted. As a result, most battery backup systems do not attempt to power the entire house. The most vital appliances, such as the refrigerator and lighting, are usually wired onto a separate essential circuit, while the non-essential items are connected to the non-essential circuit.

Considerations When Choosing A Solar Battery

With the evolving future of solar technology, you will find that more and more brands are vying for your hard-earned cash. Therefore, if you intend to buy a solar battery, you need to learn about various types of solar batteries in Australia to make an informed decision.

This section will cover the essential factors to consider when purchasing solar batteries. These crucial characteristics of solar batteries will make it easier for you to select the best solar battery for your solar power system. Here's what you need to consider:

The capacity or size

The capacity of a solar battery, measured in kilowatts, refers to the amount of electricity it can retain and discharge. The majority of solar batteries are still unable to operate at full capacity. For example, an average solar battery comes with a capacity of around 90%.

This implies that a battery with a capacity of 10 kW can only use 9 kW at its maximum capacity. The storage capacity of a solar battery is determined by the amount of energy generated by your solar panels within a duration of 24 hours. You must know the average output, then multiply it by the number of days you want your battery to run without being charged before it needs to be recharged.

For example, if your typical daily production is 6 kW and you wish to store the energy for about 15 days, you'll need a battery capacity of 75 kWh. The solar battery's storage capacity, on the other hand, is determined by your home's maximum daily electricity usage. You will not be able to receive enough power from your solar battery for the given timeframe if its capacity is insufficient.

Solar battery's lifespan

Three metrics are used to calculate the lifespan of a solar battery: the estimated years of operation, estimated throughput, and expected cycles. The estimated throughput and processes of a battery are similar to the mileage warranty on a car. Throughput allows you to analyse how much electricity your solar battery can store and distribute over its lifespan.

At the same time, cycles refer to the number of times a battery can be charged and discharged. A solar battery's lifespan is determined by the type you opt for and the amount of capacity it sheds over time. As a battery is charged and discharged regularly, its cell efficiency and ability to store a charge will eventually deteriorate.

Solar-integrated batteries usually come with a ten-year warranty that covers daily cycles. Some batteries are predicted to last ten years, while others can last up to 20 years. As such, it is advisable to enquire about this before selecting a battery to ensure optimal energy storage and battery lifespan.

If you want to guarantee your solar battery's longevity, you need to observe proper maintenance measures. For example, ensure that you keep your solar battery at an average temperature and away from extremes of heat or cold.

Depth of Discharge (DoD)

The quantity of electricity used from the battery is simply referred to as the depth of discharge. For example, a 10-kWh battery with a 90% discharge capacity enables you to consume up to 9 kWh without recharging while leaving a small amount of energy unused.

Solar batteries must always have some amount of energy retained in them. Inability to do so can result in a considerable reduction in their longevity. As a result, a greater DoD suggests a higher battery capacity.

The power rating

The power rating of a solar battery, measured in kilowatts or Amps, refers to the power that the battery is expected to generate in one hour of optimal sunlight and temperature conditions. Simply put, the power rating dictates both how many and which appliances the battery can power simultaneously.

Varying appliances require different quantities of electricity. For example, a standard compact fluorescent lamp consumes 12 Watts of power, whereas a 3-ton AC unit consumes 20 Amps or 4.8 kW. The vast majority of today's batteries have a constant power output of roughly 5 kW.

It's important to understand that solar batteries frequently feature two power ratings: continuous power rating and an instantaneous or 5-minute power rating, implying that they can offer greater power in short bursts. This is crucial if you have a sump pump or other device that requires a lot of power for it to start but then runs using a lower amount of energy.

Does The Battery Meet Safety Requirements?

All solar batteries must fulfil specific safety requirements to be licensed for use in homes and businesses. On the other hand, some battery chemistries have been examined for safety to varying degrees, going above the government-mandated safety regulations for batteries.

This implies that some battery chemistries are marginally safer than others. The most significant thing to keep in mind is that almost all batteries used in Australia are pretty safe due to the strict regulations that have been put in place.

The roundtrip efficiency

The roundtrip efficiency of an energy storage system (that is, the battery + inverter) is a system-level measurement that assesses how successfully it converts and stores electricity.

Any electrical operation involves losses, which means you'll lose some kilowatts when you convert it from direct current (DC) to alternating current (AC) or when you put power into a battery and then remove it. The roundtrip efficiency of a solar battery indicates how many units of power you get out of it for every unit you put into it.

The chemistry

The primary compound that stores power inside a battery is referred to as the battery's chemistry. Because chemistry impacts many of the features of the batteries described above, it may be the most significant characteristic to compare. Different lithium-ion chemistries, for example, might be more power-dense.

This means they store more power in a small amount of space or might be better at cycling, meaning they can perform more effectively for more extended periods. And that's just within lithium-ion chemistries; there are also differences in the chemistries of other solar batteries.

What Are The Various Solar Battery Types?

As mentioned above, when looking for a solar battery for your household's solar power system, there are quite a number of things to consider. The kind of battery you are looking for and what you want to get out of it are two factors to keep in mind.

Therefore, to aid you in your quest to select the correct solar battery for your solar power system, we have broken down the most prevalent energy storage options. All you have to do is look into them, decide which type works for you and make a purchase.

Lithium-ion batteries

Lithium-ion batteries are indeed the new kids on the block when it comes to energy storage. Electric vehicle (EV) makers understood lithium ion's promise as a power storage solution as the interest in electric cars grew. They have immediately become among the most sought-after solar battery storage banks available on the market.

When considering lithium-ion batteries, it is good to note that they nearly never need to be serviced. They seem to have an increased battery power density than lead-acid batteries, which means they can store greater energy in a small space. Residential solar installations benefit from lithium-ion batteries because they can store more power in a smaller space and allow you to utilise more of the energy stored in the battery.

This feature makes them ideal for powering a home. These batteries also have a longer lifespan, and most of them come with a 10-year warranty. Lithium-ion batteries have a more substantial depth of discharge, which means you can utilise more of the electricity stored in the battery before recharging, resulting in a longer lifespan.

Unfortunately, lithium-ion batteries are more costly than other solar energy storage systems, which is one of their main drawbacks. They also have a greater risk of burning due to a phenomenon known as thermal runaway due to their chemistry. However, if your battery is installed correctly, the chances of it catching fire are almost non-existent.

Lead-acid batteries

In the field of solar batteries, lead-acid batteries are indeed reliable. People have used deep-cycle batteries to store energy for a long time- since the 1800s. They are dependable, which has contributed to their continued stay in the battery business. In addition, this feature makes them ideal for your off-grid solar systems or standby power storage in the event of a power loss.

The two primary types of lead-acid batteries are sealed lead-acid batteries and flooded lead-acid batteries. They are the cheapest and most cost-effective energy storage alternative. They are also trustworthy and can simply be disposed of and then recycled since the technology has been available for a long time.

To function properly, flooded lead-acid batteries need ventilation and routine maintenance, which raises the risk of the battery leaking. In addition, you cannot install these batteries on their sides, which restricts how they can be installed. They also have quite a low depth of discharge, requiring more frequent charging. This feature also gives them a short lifespan (between five and ten years).

Flow batteries

Flow batteries are still relatively new in the world of energy storage, but they are becoming increasingly popular. A water-based electrolyte liquid in the battery courses between two specific sections or tanks. A chemical reaction occurs when the battery is charged, allowing the power to be stored and then discharged.

Flow batteries offer a 100 per cent depth of discharge, which is one of their top perks. This means you can make use of the entire amount of energy contained in your battery without damaging its overall health. The liquid present inside the battery is also fire-resistant, so you do not have to worry about a thermal runaway. As far as batteries go, flow batteries have the longest life span of any of the batteries listed, at 30 years!

They additionally have the added benefit of being low-maintenance. Unfortunately, flow batteries are quite a bit more costly than other forms of solar batteries due to their larger size. They also have a limited storage capacity relative to different types of batteries; thus, they must be huge to hold a significant amount of energy.

Flow batteries have a meagre charge plus discharge rates, so they must be large to hold a considerable amount of energy. However, their size and price make it difficult to adapt them to domestic use. As a result, flow batteries have yet to become a popular home choice. For large-scale installations, flow batteries are definitely the best option.

How To Care For Your Solar Batteries

To extend your preferred solar battery's lifespan, you are advised to take proper care of it. Doing so also considerably lowers the overall cost of your solar power system. Keep in mind that solar batteries can get defective in a matter of weeks if they are not adequately cared for.

Therefore, ensure that you clean the battery terminals regularly. When replacing old batteries, keep in mind that mixing can affect the performance of your batteries. Mixing in this instance refers to using old and new solar batteries simultaneously.

When you use both your old and new solar batteries together, newer batteries quickly deteriorate to the same level of quality as the older ones. As a result, combining old plus new batteries is a waste of money. Avoid this by ensuring that all of your batteries are in good working order.

Steps Taken To Clean Your Solar Battery

Step One: Remove clamps

Start by removing the clamps, beginning with the negative first.

Step Two: Use battery terminal cleaner brushes and bicarb

To clean your solar battery, use battery terminal cleaner brushes and a solution of baking soda with distilled water. Clean the terminals with some water and double-check for tight connections.

Step Three: Cover metallic parts

Then, cover the metallic parts with a commercial sealer or a high-temperature grease.

Choose The Best Solar Battery Storage

A lithium-ion battery is, in most circumstances, the ideal battery for a residential solar installation. They can store greater energy in a smaller space, release most of the energy they store, and have excellent efficiency. Because they are the most prevalent, many solar firms will be able to precisely and safely set up a lithium-ion solar battery on your property. However, if your budget is restricted, lead-acid batteries might be your best bet.

As mentioned before, they have been around for a long time and are inexpensive. Although you could use a flow battery in conjunction with your solar power system, lithium-ion and even lead-acid batteries are the most common solar batteries for a reason. Contact a professional solar company if you require any assistance in determining which solar battery storage solution will best fit your home's needs and conduct the installation.