The demand for energy storage system is growing rapidly. In 2022, the world will usher in a new stage of home solar energy storage system explosion, and the penetration rate has room to increase tenfold. Due to the maturity of energy storage system technology and cost reduction, energy storage system will start to grow rapidly in 2021. In 2022, due to the rising energy costs and electricity prices in Europe, the Russian-Ukrainian war and large scale power outages overseas, residential electricity costs are high and power supply stability is poor. The high growth of home solar energy storage system has brought about an unexpected outbreak of the home energy storage market.

1. Home solar energy storage system: the core is the solar energy storage system with battery and energy storage inverter

The core of the household solar energy storage system is solar panels + battery + energy storage inverter. Household energy storage system and solar panels are combined to form a home solar energy storage system. The solar energy storage system mainly includes solar cells, energy storage inverters (bidirectional converters), component systems and other parts. A typical system is generally 5KW ( components + inverter) supporting 10KWH energy storage battery or 10KW+10KWH energy storage battery, in which the battery is the core of the energy storage system, accounting for about 45-50% of the cost; the energy storage converter can control the charge and discharge, AC and DC For the transformation of solar energy, the cost accounts for about 10- 15%; the component system, that is, the photovoltaic system used for solar power generation, accounts for about 20-25% of the cost; the installation cost accounts for 15-20%.

Household solar energy storage system is a necessary aid for distributed energy systems. According to the application scenarios, energy storage can be divided into user side (self-generated and self-consumption, peak-valley price difference arbitrage), power generation side (renewable energy grid connection, reduction of solar energy and wind), grid side (power peak regulation, frequency regulation), transmission and distribution side and Ancillary services (5G base station backup power), etc.

2. Product series: home energy storage products are divided into integrated machine and split machine

Home energy storage system products include all-in-one and split. 1) All-in-one machine: The home-type photovoltaic energy storage and inverter integrated machine is an integrated integrated system with photovoltaic inverter, battery and controller placed inside. It can display the working status conveniently, quickly and intuitively through the touch screen, and can modify parameters and work in a variety of ways. And it is easy to use. Generally, there are three working modes: solar priority mode, AC (mains) priority mode, and SE priority mode (off-peak power consumption mode). 2) Split type (inverter + battery system): home split machine battery and inverter. The inverters are installed separately, and the user can match the household energy storage inverter according to their own needs, and can also match the switching  power supply or the inverter as a backup power supply. Generally, there are four types of hybrid home photovoltaic + energy storage systems, coupled home photovoltaic + energy storage systems, off-grid home photovoltaic + energy storage systems, and photovoltaic energy storage energy management systems.

3. Technical route: lithium iron phosphate battery is the mainstream route

The mainstream technology route of household solar energy storage system is lithium iron phosphate, and sodium ion and lithium iron manganese are new paths in the future. The technical route of energy storage battery includes lithium ion, lead battery, flow battery, etc. At present, lithium iron phosphate battery is more in line with the design requirements of energy storage battery than ternary lithium battery due to its high safety and long cycle life. It is the mainstream development route of energy storage batteries, and Tesla energy storage batteries have gradually shifted from the ternary route to the iron-lithium route. In addition, some companies such as CATL and PYLONTECH are already conducting research and development and testing of sodium ion and lithium iron manganese batteries. We expect that the technical route of energy storage batteries is expected to be further improved in the future. 

4. Industry barriers: product design and channel construction

The core barrier of household solar energy storage system lies in the adaptation and channel advantages of energy storage inverters. Home solar energy storage system, as a small energy storage battery, does not require high integrated core technology, and its core competitiveness is product design and market development (the key is market brand and channel construction). 1) Product design: mainly for adaptation with energy storage inverters (different countries/regions have different requirements) and for customer needs. For example, the BMS in the energy storage system needs to be adapted to the energy storage inverter, and the energy storage inverter controller communicates with the BMS through the CAN interface to obtain the status information of the battery pack, which can realize the control of the battery. Protective charge and discharge to ensure safe battery operation. 2) Channel construction: According to PV magazine's research, the biggest factor consumers consider when buying energy storage batteries is brand reputation. Consumers rarely know the source of the batteries and components used, and the overseas channel certification cycle is complex and relatively. In the long run, the channel construction and maintenance of energy storage manufacturers and downstream integrators and installers is particularly important.

5. Demand volume: Demand is growing rapidly, and the world is ushering in an accelerated period of home energy storage

The demand for home energy storage system is growing rapidly, with a year-on-year increase of 56% in 2021. According to BNEF data, the global installed capacity of energy storage in 2021 is about 10GW/22GWh, a year-on-year increase of 84%/105%, of which distributed energy storage capacity is about 2.5GW/5.6GWh, a year-on-year increase of 45%/40%. The installed capacity of household storage is about 1.9GW/4.4GWh, an increase of about 53%/56% year-on-year. The global home energy storage is booming. The main driving factors come from two aspects, one is the continuous increase of policy support, and the other is the high-yield economy. 

6. The original driving force for the promotion of home energy storage: the cost of electricity

The proportion of overseas clean energy power generation has increased year by year, resulting in high electricity prices. The overseas power generation structure is characterized by a relatively high proportion of non-fossil energy power generation, with nuclear power and renewable energy generation accounting for 63% of the total European power generation and oil power generation (1%). 

The reason for the high price of electricity overseas is that, on the one hand, the marketization of electricity markets overseas, especially in Europe, is relatively high, and fluctuations in natural gas prices are easily transmitted to electricity prices. In addition, the high proportion of renewable energy causes the power system to be greatly affected by weather and lack of stability, which together lead to high electricity prices overseas.