The new battery modules mainly include AC output battery modules with inverters, double-sided power generation battery modules, battery modules with snow melting function, battery modules with power storage function, etc.
1. AC output battery module
The AC output battery module is equipped with a small AC inverter, also called a modular inverter, on the back of each module, as shown in Figure 2-14. Since each battery module directly outputs AC power, the required AC power can be easily obtained by parallel combination. It can form a solar photovoltaic power generation system relatively simply and quickly. The AC output battery module has the following characteristics.
(1) The system capacity can be increased in units of the number of modules, which is convenient for system expansion.
(2) MPPT controls each module, which can reduce module loss due to partial sun occlusion and multi-directional settings, and improve system efficiency.
(3) As the DC wiring is omitted, failures due to electrical connections and corrosion can be reduced.
(4) Since a single module can form an AC photovoltaic power generation system, the flexibility of system settings is increased.
At present, the output power of AC output battery modules is 200~500w, and the line connection method is shown in Figure 2.
2. Bifacial power generation battery module
The structure of the bifacial power generation cell module is similar to the building material type double glass cell module, except that the bifacial power generation cell module is packaged with a new type of bifacial power generation cell. This type of solar cell can generate power at the same time on both sides, which can effectively improve the power generation efficiency. Among the traditional solar cells, the light conversion efficiency of monocrystalline silicon cells can reach up to about 19%, and this new type of double-sided solar cell can further increase the light conversion efficiency to 20% to 30%. At the same time, the power generation of monolithic (156mm × 156mm) monocrystalline silicon cells has also increased from 4~4.5W of traditional batteries to 4.5~6w. The bifacial power generation cell module can use the direct light on the surface of the module and the direct light or scattered light on the back of the module to generate electricity, so that the power generation of the module of the same area is significantly increased. Figure 3 shows the application of double-sided power generation battery modules in solar garden lights. The fan-shaped modules on the lamp and the modules in the middle of the light pole are all double-sided power generation battery modules.
3. Battery module with snow melting function
After the battery modules are covered by snow in winter, it will prevent or affect the power generation of the battery modules. The battery module with snow melting function can use the power of the system late at night when it encounters snow. The battery module is energized through the inverter, and the heat generated by the solar battery melts the snow on the surface of the battery module, so that the battery module can resume normal power generation.
4.Battery module with power storage function
The battery assembly with power storage function uses small, light weight and long cycle life lithium batteries as energy storage batteries. The lithium batteries are grouped and installed in the aluminum alloy frame around the battery module, and the module junction box and the controller circuit are combined into one to form a portable power generation and energy storage device, which can be powered by solar energy only by directly connecting the electrical appliances. The use of this module overcomes the problem of short life of ordinary photovoltaic power generation system energy storage lead-acid batteries, facilitates the installation, construction and maintenance of the system, and reduces the loss of line connection.