As solar technology continues to evolve, so does the cost of solar systems. Many homeowners and businesses are considering whether or not to add batteries to their solar systems. As you consider this, have you wondered why and how to add batteries to your solar system? So let us take you through the questions about adding batteries to your solar state below.
1. Why add batteries to a solar system?
The main reason for adding batteries to a solar energy system is to store the electricity generated by the solar panels, when the solar panels are generating enough electricity for home use, there is a risk of wasting energy without solar batteries. The electricity stored in the solar battery also ensures that the home’s electricity supply is normal in the event of a home power outage. And when solar panels generate electricity, there may be power fluctuations that affect the normal operation of electrical appliances, adding solar energy can reduce the impact of power fluctuations on electrical appliances.
2. How to add batteries to the solar system?
2.1 If you have an off-grid or hybrid solar system, you can add batteries as follows
2.11 Evaluate your energy storage requirements: You can start by estimating the amount of power your solar system is likely to generate per day based on the size of your solar system, and then use your home meter to get an idea of your daily power consumption and the number of hours you can supply power during a power outage.
2.12 Choose the right battery: Based on the above data, you probably know how many batteries you need, but you also need to choose compatible batteries based on your budgeted cost. But be careful to add new batteries to keep the same type, voltage and capacity with the original batteries.
2.13 Add a short-circuit switch: In order to prevent the inverter from malfunctioning and generating large currents, causing damage to the battery, you also need to install a short-circuit switch between the inverter and the battery, so that you can realize a rapid power failure when the circuit fails.
2.14 Connect the battery with the solar system: put the battery into the battery mounting frame, connect the positive and negative terminals of the battery, and lead a wire from each of the positive and negative terminals of the battery to connect to the inverter.
2.15 Checking the system: After adding the battery, you have to check the system, including whether the inverter and the battery can work normally, and whether the current conversion between each circuit is normal.
2.2 If you have a grid-connected solar system, the original grid-connected inverter does not have an output that can output DC power, before adding batteries, you also need to modify the inverter. Here are two ways to modify the inverter.
2.21 AC-coupled PV systems: You can use the AC-coupling method to ensure that the charge is charged properly. AC coupling means that only AC power is transmitted in the circuit and DC power is isolated. The application in the solar system is to ensure that the original inverter is not modified under the conditions of the grid-connected inverter and the load to add an inverter, this inverter in the role of the AC power can be converted to DC power, provided to the battery charging. Similarly, it can also convert the DC power in charging into AC power for the load to use.
AC coupling modification of the inverter method in the solar system which is the existence of two inverters, is based on the original grid-connected inverter to add a hybrid inverter, generally such a hybrid inverter is cheaper and does not cause waste.
2.22 DC coupling PV system: DC coupling means in the circuit allows AC and DC power to pass through at the same time, its application in the solar system is to replace the inverter. If you still want your solar system to be connected to the grid, you need to replace the inverter with a hybrid inverter. If you do not want your solar system to be connected to the grid, you need to change the inverter to an off-grid inverter.
In the DC-coupled conversion method there is only one inverter, which is more convenient, but the direct replacement of the inverter is more expensive and the grid-connected inverter used in the original system is useless.
After completing the modification of the inverter, you then follow the off-grid or hybrid solar system to add the method, the battery will be installed in the solar system can be.
3. Advantages and disadvantages of DC-coupled solar systems
3.1 Advantages
3.11 DC-coupled systems have simpler circuits during the conversion process, which reduces the energy loss in the conversion process.
3.12 During blackout, if the system is equipped with off-grid inverter and sufficient energy is stored in the battery. Then it will automatically switch to off-grid mode during power failure. The battery is converted into AC power by the inverter to supply the load.
3.2 Disadvantages
The cost of replacing the inverter is high, the original inverter can not be used again, resulting in waste.
4. Advantages and disadvantages of AC coupled solar system
4.1 Advantages
4.11 AC coupled system is more convenient and simple to install, can be used with a variety of inverters, if the existing inverter is retained, the installation cost is lower.
4.2 Disadvantages
4.21 AC coupled system in case of power outage, as the inverter can convert the DC power into AC power to be delivered to the grid. For security reasons, the solar system will stop functioning to prevent delivering power to the grid company, so the home will be blacked out with it, unless you are equipped with a backup power supply that can be switched to supply power in the event of a blackout to get through the power crisis.
It is more closely linked to the grid and is less likely to be disconnected from it.
4.22 It is much less efficient. The battery stores DC power, which needs to be converted to AC power before it can be used by household loads.
5. Which is better for you, DC-coupled or AC-coupled solar systems?
If you are planning to install solar batteries in the future when you install your solar system at the initial stage, it is natural to choose a storable solar system.
Most people probably didn’t think about installing battery storage when they initially installed their grid-tied system. Then you need to carefully choose from DC-coupled solar systems and AC-coupled solar systems that are more suitable for you.
Both types of battery storage systems have their advantages and disadvantages. If you want to be completely off the grid and you have enough money to cover the cost of the installation, then you can choose a DC-coupled solar system, which has a higher conversion efficiency.
If you don’t have a lot of money, then you can choose to install an AC-coupled solar system.
6. What are the benefits of installing batteries on an existing solar system?
6.1 The first benefit is that it allows us to be largely independent of the grid company and enjoy the power source even when the power goes out.
6.2 In many electricity rates are time-charged, and electricity rates go up appropriately during peak hours (afternoon or evening) to urge people to conserve electricity. And you can avoid paying high electricity bills by having solar system and energy storage system.
6.3 You can rely more on the solar system and save the electricity bill. And photovoltaic power is cleaner, which is good for the ecosystem.
7. Considerations for adding batteries to the solar system
Compatibility: Before adding batteries, you must ask to ensure the compatibility between your batteries and the solar system, only when the compatibility of your entire solar system is good enough, the system components can be coordinated with each other to fail, to ensure the stability and performance of the components.
Consider the service life of the components: when choosing the battery, you should try to choose the battery with a long service life, to avoid the second replacement of the battery in order to reduce the operating costs in the later stage. And in addition to consider the service life of the battery, but also consider the service life of the inverter, if your grid-connected inverter has been close to the use of life, then in the choice of retrofitting the inverter method, you can choose the DC-coupled photovoltaic system, which avoids the trouble of replacing the inverter again.
Battery Voltage: Battery voltage is a matter of careful consideration when purchasing batteries. It must be compatible with your PV inverter. For small PV systems typically the inverter output is 12v or 24v. regular home PV systems usually require a 48v battery.
Cost: Lithium batteries are more expensive upfront than lead acid, but they last longer and perform better. It seems more affordable in the long run.
Storage capacity: Choose the right battery capacity for your needs. Usually, the higher the capacity, the more expensive the battery.
Conclusion:
When you are going to add batteries to your solar system, you need to have a thorough understanding of your solar system and the steps to add batteries to your solar system. You add batteries by going through the above details, your solar system will surely improve the efficiency and reliability of your entire solar power system.
