What are the considerations for purchasing a 15kw off-grid solar system?

15kw off grid solar systems are usually divided into grid-connected, off-grid, and off-grid. Today we mainly talk about the design points of 15kw off-grid photovoltaic energy storage systems.

A common off-grid energy storage system is a backup power system (UPS), which is widely used in areas with frequent power outages and unstable grids, or loads that require a high guarantee rate of grid power supply. Its core component is a charging and inverter integrated machine with dual functions of charging and inverter. When the mains is normal, the charging inverter can directly connect the mains to supply power to the load, and at the same time convert the alternating current into direct current and charge the battery, and ensure that the battery will automatically stop charging when it is fully charged. When the power grid fails, The charging inverter will automatically cut off the connection between the mains and the load, start the inverter instantly, and then the battery will provide power for the load through the inverter.

The 15kw off-grid solar system is a photovoltaic energy storage off-grid system composed of photovoltaic power generation, energy storage system, and inverter. It can directly use photovoltaic modules to charge batteries to meet the needs of electrical loads. The off-grid photovoltaic power generation system is mainly suitable for some special and some electricity loads far away from the grid. There is still a large market demand space for some communication, border checkpoints, islands, or field operations and people, especially in less developed countries such as Africa. Countries and regions still have a lot of room for development and markets.

Off-grid photovoltaic energy storage power stations can also be installed in places with frequent power outages or unstable grid power supply. The battery system can not only be charged by a photovoltaic power generation system but also be charged by conventional electricity when the conventional grid is powered on to ensure power supply.

Issues to be considered in the process of designing a 15kw off-grid solar energy system

1. Leave enough margin for the 15kw inverter

Usually, 15kw off-grid photovoltaic power generation is a power system for specific loads. During the design process, the rated power of the load connected to the system should be calculated and checked, and the output power of the inverter used should be determined according to the total power of the load. Fully consider the inrush current, starting power, and reactive power that some special loads may have on the inverter when they start, and leave sufficient margin for the inverter. Once the capacity of the inverter is determined, the capacity of the connected load cannot be expanded or increased arbitrarily, so the off-grid photovoltaic power generation system should leave enough margin for the inverter.

2. Consider the matching of various loads and inverters

The 15kw off-grid photovoltaic power generation system must fully consider the matching of various loads and inverters, especially if there are inductive loads such as washing machines, refrigerators, air conditioners, etc. The wave or quasi-sine wave inverters meet the requirements of inductive loads for inverter output waveforms.

3. Calculate the average daily working time and power consumption of each load

The capacity of the photovoltaic array and battery is designed based on customer needs, so as to meet the needs of users for electricity and control the overall investment cost.

4. Taking the solar radiation of the worst month of the year as the design basis

The off-grid system must ensure that the photovoltaic system can still guarantee power supply in the month with the least amount of radiation (usually the worst month of the year is winter. This is different from the grid-connected system. The design of the grid-connected power station is based on the total annual solar radiation. ) Therefore, the off-grid photovoltaic power generation system usually designs the inclination angle of the photovoltaic array according to the best inclination angle in the worst month. That is to say, the array inclination angle of the off-grid photovoltaic power generation system is usually 2° to 8° larger than the local geographic latitude angle to take into account the weak solar radiation in winter.