How to choose a household backup energy storage battery?

How to choose a household backup energy storage battery?

No matter how big or small your house is, the key depends on whether you have calculated the daily electricity demand of your house in the past and considered in advance how to meet your daily energy needs. For example, is there a power grid in the area? If not, obviously you need to consider using solar panels to get free electricity. When you consider all of these, you can save a lot of money on future electricity bills, which also allows you to optimize your power distribution plan more flexibly. Especially when you decide to live in an environment without grid power, you need to consider pure off grid power. In this case, it is very necessary to use solar photovoltaic panels to store excess electricity during the day for nighttime use.

If your place has a power grid, you will have more choices. For example, you can sell your electricity during high electricity prices (peak usage) and earn additional income. According to data, with reasonable planning, it is hoped that the cost of daily electricity consumption and the corresponding configuration of photovoltaic energy storage systems can be fully recovered within 6-8 years, and a stable source of income can be created in the following period. Therefore, in the long run, a carefully planned grid connected/off grid power system can save you thousands of dollars annually. Currently, more and more people are realizing the significance of doing so, which has become a popular trend.

Perhaps many people have already consciously built their own power supply system, but do not know how to start. Today's article is here to help everyone solve this problem. Today, we will discuss from the following four aspects:

View local guidelines and refer to local national power guidance documents.
Considering energy conservation and consumption reduction from the perspective of the equipment itself.
Calculate daily and monthly electricity demand.

How to configure the appropriate number of photovoltaic panels and energy storage battery packs.

1. Check the local guidelines and refer to the local national power guidance documents
If you plan to purchase a solar power supply device and energy storage system, please be sure to consult the relevant policy documents with the local power bureau or relevant departments first. Some countries and regions explicitly require all grid connected systems to sell electricity. The power grid has precise time, certificate, and equipment safety requirements, which must be judged according to local guidance documents. It is also recommended to consult experienced electricians to conduct a rational analysis of the power supply system designed for you, in order to avoid irreversible fire or short circuit hazards caused by erroneous views, or consult our online experts.

2. Considering energy conservation and consumption reduction from the perspective of the equipment itself
When your house relies entirely on off grid power, the amount of electricity you can get every day is limited. If your configuration cannot meet your daily needs, there will be a shortage of battery and you will not be able to receive additional supplements. In this case, if you don't have plans to upgrade your solar panels or add additional energy storage batteries, the best way is to save energy. For example, replacing household light bulbs with energy-saving lamps and using induction cookers or microwaves instead of high-power electric ovens. Set the opening time of the air conditioner and close the doors and windows, instead of letting the air conditioner run at full power 24 hours a day. Or the simplest way is to turn off the lights and unnecessary electrical equipment, which is easy for us to do.

Considering that photovoltaic panels are also highly efficient, we can generally calculate based on an efficiency of 90%. Solar panels themselves also have different power levels. Of course, they are limited by materials and processes. Solar panels of different power have different prices, sizes, and weights. Let's take the common 260W solar panel as an example. If multiplied by 90% efficiency, the actual power is 234W. If we need a 2.5kw solar panel, then we need at least 2500w/234w=10.6, which is calculated as 11 solar panels according to integers. This is the calculation method for solar panels.

The use of batteries is also very tricky. If we always use batteries according to their maximum design capacity, their lifespan will quickly decline, so we recommend keeping the discharge depth for daily use below 80% DoD. That is to say, the maximum usage of the 80Ah battery we use in daily life is 100%, and the remaining 20% can be used to maintain the battery pack. Considering this idea, if we need to prepare a 6kWh battery pack, we suggest preparing a 6kWh/80%=7.5kWh battery pack.

Sometimes, we may encounter cloudy days, but solar panels are difficult to work on cloudy days. To avoid such unexpected situations, we can reserve an extra 1-2 days of electricity and face this situation calmly.
In summary, when considering the power supply system, we need to consider extending the overall lifespan of the system as much as possible in order to save costs and achieve the best benefits. Fortunately, lithium batteries are a proven choice that can provide the best performance and longest lifespan.