Interest in solar energy storage has grown significantly over the last couple of decades. According to the Solar Energy Industries Association (SEIA), most homeowners and businesses are increasingly opting for solar systems paired with battery storage.
Its growth over the next couple of years is expected to be immense when this trend is new. In the next 5 years, it’s expected that over 25% of all power solar systems will have some form of energy storage.
If you are planning to install a solar system for home paired with battery backup, you may be wondering where to start. Well, you’ve come to the right place. In this battery storage buying guide, we will provide you with all the information that you need about storage batteries for solar panels.
How do you consider when purchasing battery storage – this guide will enable you to make the best decisions if you want to buy battery storage.
What is a Storage Battery and How Dose it Work?
Since the invention of the lead-acid battery in 1958, its use and development have a history of more than 100 years. It refers to the battery used in solar power generation equipment, wind power generation equipment, and renewable energy saving energy. The energy storage batteries are divided into the following three categories:
1、Exhaust type lead-acid battery for energy storage – battery with liquid replenishing and gas releasing device on the battery cover.
2、Valves regulated lead-acid battery for energy storage – each battery is sealed, but it is equipped with a valve to allow gas to overflow when the internal pressure exceeds a certain value.
3、Lead-acid battery for colloidal energy storage – batteries with colloidal electrolytes.
Its basic structure consists of plate, separator, electrolyte, and shell.
Solar panels make more electricity during the middle of the day than they do at any other time.
The middle of the day also happens to be when homes use the least amount of electricity. Because of this, your solar panels will produce a lot of electricity in the afternoon that you won’t need.
Solar batteries can store that extra solar energy so you can use it later on. This lets you power your home on clean renewable energy from your solar panels, even when they aren’t producing electricity.
What’s great about installing a solar battery is that it allows you to be less reliant on the grid while ensuring you have access to reliable backup power when there’s a power outage.
The Application of a Storage Battery
1、Transportation: Cars, trains, tractors, etc;
2、Telecom Power: Posts and telecommunications, communications, power stations, power transmission, etc;
3、Station terminal: Forklift, transport vehicle, signal lamp, instrument, etc;
4、Underground mine: Miner’s lamp, transport vehicle, UPS power supply, lighting system, etc;
5、Space navigation: Ships, fishing boats, fish lights, beacon lights, precision instruments, etc;
6、Natural energy system: Solar energy, wind energy, geothermal energy, tidal energy system, etc;
7、Banks, schools, shopping malls, and hospitals: UPS power supply, precision instruments, emergency lights, etc;
8、System: UPS uninterruptible power supply lamp;
9、Tourism and entertainment: Sightseeing car, electric toys, golf cart, emergency lights, etc;
10、Defense industry: Aircraft, tanks, armored vehicles, artillery, ships, nuclear submarines, radar systems, missile launching systems, precision instruments, etc.
Benefits of a Solar Battery
Energy bill savings: By storing energy when demand is low, you can reduce the amount you buy from your energy supplier when energy use is high, thus saving on your energy bill.
Backup Power Supply: Some solar batteries will enable you to use your solar electricity. If there is a power cut, you’re not left without power or lighting. When there is a power cut strikes a store of this energy could be invaluable to your family.
Grid-connected vs off-grid
There are four principal methods to helping you to set up power for your home.
Grid-connected (no solar)
The most ordinary set-up the electricity is all from the main grid. The home has no solar panels or battery.
Grid-connected solar (no battery)
The most typical installation method is to install solar panels in the home. During the day, the solar panels’ supply power and the home use this power first, then resorting to grid power for any extra electricity. This is needed on low sunlight days and at times of high power usage.
Grid-connected solar + battery (aka “hybrid” systems)
They have solar panels, a battery, a hybrid inverter (or possibly multiple inverters), with a connection to the main electricity grid. During the solar panels’ supply all day, the home usually uses the solar power first and then uses any excess to charge the battery. At times of high power usage or night and on low-sunlight days, the home draws power from the battery, and as a last resort from the grid.
The system is not connected to the main grid. All the electricity in the house comes from solar panels, and there may be other ways to generate electricity, such as wind power. Batteries are the main source of power at night and on days of insufficient sunlight. The last backup device is usually a diesel generator, which can also be started when the power demand suddenly increases (such as when the water pump starts).
Off-grid systems are usually more complex and expensive than grid-connected systems. They need more solar and battery capacity than typical grid-connected systems and may need inverters that can withstand higher loads to cope with peak demand. Families far away from the grid need to be particularly energy-efficient and need to manage load demand throughout the day.
The off-grid system is usually only suitable for remote attributes where the grid connection is not available or the installation cost is too high.
Best Off-Grid Battery for Vacation Homes
If you have an off-grid vacation home, you don’t visit regularly? And you want a battery that doesn’t require regular maintenance because you’ll only be on-site a few times a year.
In this situation, a sealed AGM battery is the best choice.
Low capacity is good because you don’t need to store all year round. We also skip the advanced lithium option because it’s overkill for a system that’s only used a few times a year.
These batteries are relatively cheap. You don’t have to make a huge investment in a property that you don’t spend that much time on.
The Best Battery for Grid-Tied Backup
If you have a grid-tied system with a backup battery for an emergency, you don’t need a battery with a huge storage capacity. Therefore, we suggest using the same battery as above: battery with sealed AGM:
You only use batteries when you need them. This kind of battery can only be used when you lose power, hopefully not more than once a year.
Grid-connected batteries require low maintenance. You want a battery that doesn’t need maintenance, and it should work in the very few cases you need.
What happens in a blackout?
A battery doesn’t necessarily protect you in the event of a blackout under the most of grid-connected. Althought you have solar panels to produce power and a charged battery ready and waiting, you may still lose all power to your home. The reason is grid-connected systems have what’s known as “anti-islanding protection”. The grid and any engineers working on the lines must be protected from generating “islands” during a blackout. For example your solar panels , which accidentally pump power, down the lines. To shut down entirely is the simplest way to provide anti-islanding for most solar PV systems. Therefore, when it senses a grid blackout, your solar PV system shuts down and you have no household power at all.
More complex inverters can provide anti-islanding protection during a blackout, but still keep the solar panels and batteries operating, giving the house some power. However, such a system may cost a little more, because the hardware is more expensive, and you may need more solar and battery capacity than you think of a house that can last for a few hours during a blackout. You can choose to allow only important household circuits to operate in this situation, such as refrigerators and lighting. This may require additional wiring work.
How long do solar batteries last?
In principle, If not subjected to extreme temperatures, most solar battery types should be able to last 10 years or more under normal usage. There is not enough market data to show whether solar batteries typically last that long in real-world home installations, however, recent generations of batteries have only been around for a few years and not many homes have solar batteries.
Are solar batteries worth it?
Many people don’t agree batteries make full economic sense to most families. Batteries are still relatively expensive now, and the payback period is usually longer than the battery’s warranty period (usually 10 years). But the prices of batteries are falling, and it may be the right decision to combine batteries with any solar photovoltaic system in two or three years.
Installing solar batteries provides the greatest benefits to owners living in areas with frequent blackouts that do not provide full net retail metering, or if there are battery incentives available in your area. If the main reason why you use solar energy is environmental protection, solar cells are also a good choice, because they can maximize the use of renewable energy in your home.
How to choose a Storage Battery?
When it comes to buying battery storage, you don’t just choose any that you come across. You need to pay attention to various specifications and factors, to ensure you choose the right storage battery for your home or business. Having said that, here are some of the factors that you need to consider when buying a battery backup system:
1、The quality of energy storage battery. First of all, the appearance of the battery should be observed to see if the battery is damaged or protruded. The energy storage battery has potential safety hazards under the above circumstances. It must not be used; otherwise, there will be unexpected consequences. The second is to know the material of the energy storage battery. As we all know, lead, as the core material of energy storage battery, its quality determines the quality of the battery. Secondly, it depends on the material of the battery shell.
2、Warranty time of energy storage battery. Batteries are not like fast-moving products. Its life cycle is very long, usually about five years, some even longer. If there are quality problems during this period, maintenance personnel are required to carry out maintenance, which is also a small cost. Therefore, warranty time is very important. This big brand of the battery warranty period is usually one year, after-sales maintenance procedures cumbersome. On the contrary, some domestic brands of energy storage batteries are much cheaper after the sale.
3、Durability: Lead-acid batteries are generally deep charged and discharged less than 400 times, with a memory and service life of about two years. If the maintenance-free lead-acid is used, it should be noted that the water loss of the battery is small, and distilled water is generally not added in use.
4、 Volume and quality: Generally, the weight of the sunshine lead-acid battery pack is 16-30kg, and the volume is large. It depends on your own needs.
5、 Warranty period: At present, the mainstream battery in the market is 12 V. The warranty period is one to two years.
Precautions for use
(1) The time of current discharge should not be too long, so when starting, the time of each start should not exceed 5S, the interval between two adjacent starts should be 15s, and the horn should not be honked for a long time
(2) When the charging voltage increases by 10% ～ to 12%, the service life of the lead-acid battery will be shortened by about 2 / 3.
(3) Try to avoid the lead-acid battery working under the condition of over-discharge and undercharge for a long time, and can not work under the condition of small current discharge for a long time.
(4) The lead-acid battery should be changed frequently to ensure that it works in a fully charged state. If the lead-acid battery is discharged, it must be fully charged within 24 hours.
(5) When using the lead-acid battery in winter, special attention should be paid to keep the battery fully charged, to prevent the relative density of electrolyte from decreasing and causing the shell to crack.
(6) The lead-acid battery should be kept properly. It should be protected from direct sunlight and isolated from heat source; No inversion, lying, impact, or heavy pressure is allowed; Keep in a dry, clean, and well-ventilated place.