1. The composition of the solar energy system
The solar power generation system consists of solar modules, solar controllers, and batteries (groups). If the load is an AC device (220V or 110V), an inverter needs to be configured. The functions of each part are as follows:
(1) Solar panels: Solar panels are an important part of the solar power generation system, and they are also the most valuable part of the solar power generation system. Its function is to convert the radiant energy of the sun into electrical energy, or send it to the battery for storage, or to push the load to work.
(2) Solar controller: The solar controller is the function of controlling the charging and discharging management of the battery by the solar module, such as overcharge, overdischarge protection, temperature compensation, etc. Other additional functions such as light-controlled switches and time-controlled switches should be optional for the controller;
(3) Inverter: The electricity generated by solar energy is direct current, which cannot provide electrical energy to AC equipment. It is necessary to convert the direct current energy generated by the solar power generation system into alternating current energy, so a DC-AC inverter is required.
(4) Batteries: Generally, lead-acid batteries and colloidal batteries are mostly used. In small and micro systems, nickel-metal hydride batteries, nickel-cadmium batteries or lithium batteries can also be used. Its function is to store the electrical energy emitted by the solar panel when there is light, and release it when needed.

2. Solar system configuration calculation:
1. Inverter rated power = rated load power * safety factor
(100W*5+25W*5+55W*3+100W)*1.2-1.3=890W*1.2=1112W
(Note: The refrigerator should choose an inverter with more than 5 times of its rated power. For example, the above 100W refrigerator needs to be equipped with an inverter of more than 500W);
2. The daily power consumption of the load = the sum of the daily power consumption of each load = 3545Wh;
3. Inverter daily power consumption = load daily power consumption / inverter efficiency
3545Wh/0.85=4170Wh (daily power generation of solar modules>=inverter daily power consumption can ensure the stable operation of the system, without considering the premise of rain);
4. Solar module power = daily power generation of solar modules / average sunshine peak time * loss coefficient 4170Wh/5.5h*1.3≈1000Wp (daily average sunshine peak time is about 5.5 hours);
5. Battery pack capacity = daily power consumption of the inverter/system rated DC voltage/discharge depth 4170Wh/24VDC/0.7-0.8=217Ah
3. Solar system configuration selection: (provided according to Hanse’s solar products)
1. Inverter: 1000W/24VDC/220VAC/50HZ
2. Solar module: 250Wp/36V*4 (four parallel inputs)
3. Solar charge controller: 24VDC/50A (1000Wp/24V≈42A)
4. Battery pack: 12V/200Ah*2 (two input in series)
5. Battery cabinet: C2 (200AH/12*2)