The design of small-sized rooftop solar power generation system includes two aspects: capacity design and hardware design. The main purpose of capacity design of distributed solar generation system is to calculate the number of solar modules and batteries needed for the distributed power generation system to work reliably during the whole year. At the same time, we should coordinate the relationship between the maximum reliability and the cost of distributed photovoltaic power generation system, and reduce the cost of distributed solar power generation system as much as possible to meet the maximum reliability.

The main purpose of hardware design of distributed photovoltaic power generation system is to select appropriate hardware equipment according to the actual situation, including the selection of solar module, bracket design, inverter selection, cable selection, control and measurement system design, lightning protection design and distribution system design, etc. In the design of distributed photovoltaic power generation system, we need to consider both software and hardware. For different types of distributed photovoltaic power generation system, the content of software design is not the same.

Before the design of distributed photovoltaic power generation system, we need to understand and obtain some basic data necessary for calculation and equipment selection: for example, the geographical location of distributed photovoltaic power generation system installation, including location, latitude, longitude and altitude; the meteorological data of the area, including monthly total solar radiation, direct radiation and scattered radiation, annual average atmospheric radiation Mild, the highest and lowest temperature, the longest continuous rainy days, the maximum wind speed, hail, snowfall and other special meteorological conditions. The distributed photovoltaic system is advanced, integrable, scalable and intelligent to ensure the safety, reliability, and cost-effectiveness of the system.

1) advanced nature. With the increasing emphasis on renewable energy, the development and utilization of renewable energy has become the development trend of new energy strategy. According to the characteristics of the local solar sunshine, power supply facilities and power load, it is an advanced power supply plan to choose solar energy resources to build distributed photovoltaic power generation system, which is not only energy saving and environmental protection, but also can avoid the huge investment of power cable laying (far away from the power load of the municipal power supply).

2) Integrity. Solar distributed photovoltaic power generation system includes: solar module, storage battery, controller, inverter, and other parts. Distributed solar power generation system can independently provide power to the outside world, and form a complete off grid and parallel distributed photovoltaic power generation system with other power loads and municipal power supply. The distributed photovoltaic power generation system should have perfect control system, energy storage system, power conversion form, lightning protection and grounding system, etc. to form a unified whole with integrity.

3) Scalability. With the rapid development of solar photovoltaic power generation technology, the function of distributed photovoltaic power generation system will be more and more powerful. This requires that the distributed photovoltaic power generation system can adapt to the expansion and upgrading of the system. The solar module of the distributed photovoltaic power generation system should be composed of parallel module structure. When the system needs to be expanded, the panel module can be directly added in parallel. The controller or inverter should also adopt the modular structure. When the system needs to be upgraded, the module of the system can be directly expanded instead of the original module In order to make the distributed photovoltaic power generation system have good scalability, all the devices can be reserved.

4) The degree of intelligence. The designed solar distributed photovoltaic power generation system should not need any manual operation in the use process. The controller can control the output of the load end according to the capacity of solar modules and batteries. All functions are automatically controlled by the microprocessor. It should also be able to detect the working state of the solar distributed photovoltaic power generation system in real time and collect the distribution data regularly or in real time The status data of the main components of the PV power generation system are uploaded to the control center. Through computer analysis, the working status of the equipment can be mastered in real time. For the equipment with abnormal working status, the fault alarm information can be sent out, so that the maintenance personnel can eliminate the fault in advance and ensure the reliability of power supply.

The design of distributed photovoltaic power generation system must have high reliability to ensure the normal use under harsh conditions. At the same time, the system is required to be easy to operate and maintain, which is convenient for the operation and daily maintenance of users. The design, manufacture, and construction of the whole set of distributed photovoltaic power generation system should have low cost, and the selection of equipment should be standardized and modular, to improve the interchangeability of spare parts, and the system should reserve expansion interface to facilitate the expansion of scale and capacity in the future.

Ningbo Raytech New Energy Materials Co., Ltd. specializes in “PV Modules Manufacturing and System Integration” and “Smart Panel Materials Manufacturing”. The company has independent product R&D teams, national key laboratory and 1.2GW full-automatic manufacturing line. Raytech Double-glass modules come with 12-year product warranty and 30-year performance warranty (2 years and 5 years longer than industry's standard product / performance warranty respectively).