家庭儲能通常與戶用光伏配合使用，裝機量迎來高速增長。家庭儲能系統(tǒng)，又稱電池儲能系統(tǒng)，其核心是可充電的儲能蓄電池，通常以鋰離子或鉛酸電池為基礎(chǔ)，由計算機控制，在其他智能硬 件及軟件的協(xié)調(diào)下實現(xiàn)充電和放電循環(huán)。家庭儲能系統(tǒng)通?？膳c分布式光伏發(fā)電相結(jié)合形成家庭光儲系統(tǒng)。從用戶側(cè)來看，家庭光儲系統(tǒng)在降低電費的同時，可以消除停電對正常生活的不良影響；從電網(wǎng)側(cè)來看，支持統(tǒng)一調(diào)度的家庭儲能設(shè)備可以緩解高峰時段的用電緊張并為電網(wǎng)提供頻率修正。

根據(jù)光伏和儲能系統(tǒng)的耦合方式的不同，分為直流耦合系統(tǒng)和交流耦合系統(tǒng)，分別適合與新裝光伏系統(tǒng)的增量市場和已裝光伏系統(tǒng)的存量市場。增量市場空間更大，是未來市場增長的主要動力：

（1） 增量市場（目標(biāo)家庭新安裝光伏+儲能系統(tǒng)）：一般使用直流耦合產(chǎn)品。直流耦合的儲能系統(tǒng)包含電池系統(tǒng)和混合逆變器，混合逆變器兼具了光伏并網(wǎng)逆變器和儲能變流器的功能。直流耦合的優(yōu)勢在于，光伏和儲能電池都通過混合逆變器完成變流，不需要額外安裝光伏并網(wǎng)逆變器，系統(tǒng)集成度更高，安裝和售后服務(wù)都更方便，同時便于智能監(jiān)測和控制。有部分已經(jīng)安裝好光伏系統(tǒng)的家庭選擇拆除原有的光伏并網(wǎng)逆變器，新安裝混合逆變器。

（2） 存量市場（目標(biāo)家庭已安裝光伏，新增儲能系統(tǒng)），一般使用交流耦合產(chǎn)品。只需加裝蓄電池和儲能變流器，不影響原來的光伏系統(tǒng)，而且儲能系統(tǒng)的設(shè)計原則上和光伏系統(tǒng)沒有直接關(guān)系，可以根據(jù)需求來定。交流耦合的優(yōu)勢在于高安全：交流耦合方式下，能量匯集于交流端，既可以直接提供給負(fù)載使用或者送入電網(wǎng)，也可以通過雙向變流器直接向蓄電池充電，可以選用低壓 PV 和低壓電池，消除儲能系統(tǒng)中的直流高壓風(fēng)險。

根據(jù)系統(tǒng)是否并入電網(wǎng)，家庭儲能系統(tǒng)可以分為并網(wǎng)系統(tǒng)和離網(wǎng)系統(tǒng)，核心差異在于是否接入電網(wǎng)，目前多數(shù)區(qū)域使用的是并離網(wǎng)一體機系統(tǒng)。（1）并網(wǎng)系統(tǒng)，光伏和儲能系統(tǒng)可以接入電網(wǎng)，在光伏或電池的電量不足時可以從電網(wǎng)購電。適合電力系統(tǒng)穩(wěn)定、電價相對較低的區(qū)域。（2） 離網(wǎng)系統(tǒng)，適合于沒有電網(wǎng)的沙漠、海島等地區(qū)或者電網(wǎng)不穩(wěn)定需要自發(fā)自用的區(qū)域。使用離網(wǎng)儲能變流器，通常具備柴油發(fā)電機接口，在夜間電池供電不足時補充電力。（3）并離網(wǎng)一體機，具有并離網(wǎng)切換功能或者將并網(wǎng)、離網(wǎng)模式整合在一臺機器中，可以在停電時完成切換進入離網(wǎng)模式，適合電力系統(tǒng)不穩(wěn)定、經(jīng)常停電的地區(qū)。

Household energy storage is usually used in conjunction with household photovoltaic, and the installed volume has ushered in a rapid growth. The core of home energy storage system, also known as battery energy storage system, is a rechargeable storage battery, usually based on lithium-ion or lead-acid batteries, controlled by a computer, under the coordination of other intelligent hardware and software to achieve charging and discharging cycle. Home energy storage system can be combined with distributed photovoltaic power generation to form a home optical storage system. From the user side, the home optical storage system can not only reduce the electricity cost, but also eliminate the negative impact of power failure on normal life. From the grid side, home energy storage devices that support unified scheduling can alleviate peak hours and provide frequency correction for the grid.

According to the different coupling modes of photovoltaic and energy storage systems, they are divided into DC coupling system and AC coupling system, which are suitable for the incremental market of newly installed photovoltaic systems and the stock market of installed photovoltaic systems respectively. Larger incremental market space is the main driving force for future market growth:

(1) Incremental market (newly installed PV + energy storage system in target households) : DC coupling products are generally used. The DC coupled energy storage system consists of a battery system and a hybrid inverter, which has the functions of photovoltaic grid-connected inverter and energy storage converter. The advantage of DC coupling lies in that both photovoltaic and energy storage batteries are converted through hybrid inverters, which does not require additional installation of photovoltaic grid-connected inverters. The system is more integrated, convenient for installation and after-sales service, and convenient for intelligent monitoring and control. Some households that have installed PV systems choose to remove the original PV grid-connected inverter and install a new hybrid inverter.

(2) Stock market (target households have installed PV and newly added energy storage system), AC coupling products are generally used. Only need to install battery and energy storage converter, does not affect the original photovoltaic system, and the design of energy storage system in principle and photovoltaic system has no direct relationship, can be determined according to demand. The advantage of AC coupling lies in high safety: In AC coupling mode, energy is collected at the AC end, which can be directly supplied to the load or sent to the power grid, or directly charged to the battery through the two-way converter. Low-voltage PV and low-voltage batteries can be used to eliminate the risk of DC high voltage in the energy storage system.

According to whether the system is integrated into the power grid or not, the home energy storage system can be divided into grid-connected system and off-grid system. The core difference lies in whether the system is connected to the power grid or not. At present, most regions use the off-grid all-in-one system. (1) Grid-connected system: photovoltaic and energy storage systems can be connected to the power grid, and electricity can be purchased from the power grid when photovoltaic or battery power is insufficient. Suitable for stable power system, relatively low electricity price area. (2) Off-grid system, suitable for desert, island and other areas without power grid or unstable power grid need to spontaneous self-use. Use off-grid energy storage converters, usually with diesel-generator interfaces, to replenish power at night when battery power is low. (3) Off-grid integrated machine, with off-grid switching function or the integration of grid-connected and off-grid modes in one machine, can complete the switch to off-grid mode in the case of power failure, suitable for unstable power system, frequent power failure areas.

Household energy storage is usually used in conjunction with household photovoltaic, and the installed volume has ushered in a rapid growth. The core of home energy storage system, also known as battery energy storage system, is a rechargeable storage battery, usually based on lithium-ion or lead-acid batteries, controlled by a computer, under the coordination of other intelligent hardware and software to achieve charging and discharging cycle. Home energy storage system can be combined with distributed photovoltaic power generation to form a home optical storage system. From the user side, the home optical storage system can not only reduce the electricity cost, but also eliminate the negative impact of power failure on normal life. From the grid side, home energy storage devices that support unified scheduling can alleviate peak hours and provide frequency correction for the grid.

According to the different coupling modes of photovoltaic and energy storage systems, they are divided into DC coupling system and AC coupling system, which are suitable for the incremental market of newly installed photovoltaic systems and the stock market of installed photovoltaic systems respectively. Larger incremental market space is the main driving force for future market growth:

(1) Incremental market (newly installed PV + energy storage system in target households) : DC coupling products are generally used. The DC coupled energy storage system consists of a battery system and a hybrid inverter, which has the functions of photovoltaic grid-connected inverter and energy storage converter. The advantage of DC coupling lies in that both photovoltaic and energy storage batteries are converted through hybrid inverters, which does not require additional installation of photovoltaic grid-connected inverters. The system is more integrated, convenient for installation and after-sales service, and convenient for intelligent monitoring and control. Some households that have installed PV systems choose to remove the original PV grid-connected inverter and install a new hybrid inverter.

(2) Stock market (target households have installed PV and newly added energy storage system), AC coupling products are generally used. Only need to install battery and energy storage converter, does not affect the original photovoltaic system, and the design of energy storage system in principle and photovoltaic system has no direct relationship, can be determined according to demand. The advantage of AC coupling lies in high safety: In AC coupling mode, energy is collected at the AC end, which can be directly supplied to the load or sent to the power grid, or directly charged to the battery through the two-way converter. Low-voltage PV and low-voltage batteries can be used to eliminate the risk of DC high voltage in the energy storage system.

According to whether the system is integrated into the power grid or not, the home energy storage system can be divided into grid-connected system and off-grid system. The core difference lies in whether the system is connected to the power grid or not. At present, most regions use the off-grid all-in-one system. (1) Grid-connected system: photovoltaic and energy storage systems can be connected to the power grid, and electricity can be purchased from the power grid when photovoltaic or battery power is insufficient. Suitable for stable power system, relatively low electricity price area. (2) Off-grid system, suitable for desert, island and other areas without power grid or unstable power grid need to spontaneous self-use. Use off-grid energy storage converters, usually with diesel-generator interfaces, to replenish power at night when battery power is low. (3) Off-grid integrated machine, with off-grid switching function or the integration of grid-connected and off-grid modes in one machine, can complete the switch to off-grid mode in the case of power failure, suitable for unstable power system, frequent power failure areas.