Solar power installation and technical issues to note

07-01-2022 13:11:45
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Solar power system is a very ”hot” trend recently. But has anyone pointed you out the installation instructions for this system? Intech Energy will help you have a detailed look at the notes when installing solar power.

Mục lục

1. Expected savings rate and demand for solar power (kWh)?

Solar power is used for the purpose of saving electricity, using the sun to generate energy. To compare how much savings you consume in a year. You just need to check the electricity bill in the months to determine the average usage demand. Sunny months will give more yield than rainy months. A suitable PV system has a selectivity ratio of enough power level to cut power consumption by a large amount.

Tip: Before the Ministry of Industry and Trade approves the electricity price (FIT2) expected at the end of March 2020, if you need to use a lot during the day, you should prioritize investing in installing solar power systems. As for customers who have needs but use it a lot at night, they should review the investment with the allowed budget. The output investment from PV is about 70% of the current power demand.

Tỷ lệ tiết kiệm kỳ vọng và nhu cầu sử dụng điện mặt trời

Tỷ lệ tiết kiệm kỳ vọng và nhu cầu sử dụng điện mặt trời Intech Energy

2. Determine the available space when installing solar power.

Roof area and buildability determine the number of solar panels. Based on the size of your house, draw a diagram of your roof on a piece of paper, determining the specific orientation. If you want to be more thorough, you can use the free tool Google SketchUp or the AutoCAD program. Or contact a professional consulting unit for accurate and reasonable calculation.

Tip: usually the panels will be installed in the South for optimal output. 1kWp solar panels need from 7-8m2 of ground area including maintenance space, distance between battery arrays.

Analyze the distance and direction of shadows between panels and other objects.

3. Calculate the amount of energy the solar battery system can generate

You can refer to the website of the NREL (US National Renewable Energy Laboratory) for statistics on solar radiation data from which production estimates can be calculated. You can also use PV Watts' solar calculator or use specialized software like PVSYST (we recommend letting a professional do the math for you) to get a 12-month relative output forecast.

Tip: for the Ho Chi Minh area, a 1kWp solar panel system, if installed according to standards, will generate an average of 4-4.5 kWh/day. Balancing the amount of electricity generated from the PV system and using up this amount of electricity is the most optimal.

Tính lượng năng lượng từ hệ thống pin năng lượng mặt trời có thể tạo ra

4.Shade and yield problems

Shadows will reduce the output of your system and can also damage the solar cells. If there are obstacles such as trees or buildings in the vicinity of your roof that could cast shade, you need to be careful. Shadows will also affect performance, not just that panel but a whole series of batteries in series. You can use specialized software to analyze detailed gloss, spacing of panels for solar power systems.

Tip: should find out, ask the installer to clarify the problem of shading and the reduction that determines the effectiveness of the system.

5. Choose the right solar panels.

On the market today there are hundreds of different solar panels, determine which type (poly/ mono/ perc/ Twin/ double glass…) is suitable. The selection of solar panels needs to match the inverter output voltage and current parameters, please note this. Other differences, such as color and financial limitations can also be a factor.

6. Choose inverter technology for solar installations.

Choosing an inverter from among the many available is not easy. Consider suitable technology such as string inverters/central inverters/DC optimized inverters. In order to choose the right inverter, it is necessary to consider the purpose of the investment plan (need high performance?, safe monitoring solution?, good cost?, brand of origin?!...).

Tip: Consider the following: Quality & Reliability/ Service & Support/ Guarantee/ Features/ Features/ Monitoring System/ Price.

Currently, the majority of residential and industrial customers choose string inverters (String inverters) because of their optimization of investment yield, as well as being suitable for their needs. For solar power plants (PV Plant) with a capacity of MWp, a central inverter will be selected to ensure commercial operation.

Chọn công nghệ biến tần cho lắp đặt điện mặt trời

Tip: For string inverters, the PV capacity should be designed to be 110%-120% larger than the AC capacity of the inverter (depending on the design parameters of each brand) to optimize efficiency. operating efficiency, reducing investment costs.

7. Chọn kệ phụ kiện khung cơ khí lắp đặt điện mặt trời.

Keep in mind that 10% to 25% of the total cost will be the mechanical mounting system. Take the time to decide which racking system is best for your budget and for your roof. The solar power system will last at least 20 years and it is one of the key components because it protects both the roof and the solar panels. One small mistake can damage the roof or hurt people or property.

8. Electrical supplies, PV power cables, indispensable components.

Choose a dedicated DC cable

Some projects do not focus on choosing a specialized DC power cable for installing solar power systems. You should consider because PV DC cabling will be subjected to very high voltages for example 280 – 800V and currents up to 10A with high discharge potential. On the other hand, DC cables will have to be installed outdoors for 25 years and need to be UV-resistant, heat-resistant, and anti-oxidation for good electrical contact...

Some customers and even construction units mistakenly believe that ordinary AC cables can be replaced with dedicated DC cables. This is extremely wrong.

Tip: use a dedicated 2-layer XLPE DC cable that withstands 1000V/1500V DC, meets IEC standards, TUV or UL certified. In addition, using T4, MC4 connector accessories to connect points, junction boxes must use fireproof type, note that do not connect spare cables wrapped with electrical tape, so use specialized electrically resistant terminals. high pressure.

AC cable selection

Normally, to choose AC wire for electrical load, the parameter to note is the maximum load current (Ampere) to calculate the wire cross-section to use. However, for grid-tied solar power systems, you need to further calculate the voltage drop over the wire length (ΔU) from the inverter to the grid connection point to choose the most suitable wire cross-section.

In many cases, the selected AC wire size only meets the current criteria but does not consider the allowable voltage drop on the wire. When the solar power system reaches peak capacity and pushes electricity to the national grid (selling surplus power), the system is "Shutdown". The main reason is that the voltage drop on the AC wire is too large, so in order for the grid-tie to push the excess power to the grid, it is necessary to raise the voltage higher, when the voltage is higher than the allowable threshold of the grid-tie, the device will restart, interrupting operations. More dangerously, some devices in the house may be affected, leading to reduced life or explosion, causing unsafety.

Tip: You should carefully calculate and choose the right AC cable of the right size and quality. Should choose a larger wire size to limit power loss on the line.

Switching and protective devices

Similar to the DC cable for PV panels, the switchgear, PV side protection should choose specialized types, should not use ordinary CB AC types on the market to replace. Because the nature of AC and DC are different, the closing and closing principles of the CBs will also be different.

In addition, to install a stable and safe solar power system, in accordance with electricity industry standards. You should install or ask the installer to use additional DC, AC lightning arresters and grounding systems.

9. Choosing a contractor, solar power installation consulting unit

Professional contractors will provide you with many optimal solutions to suit your needs. Along with a long-term reputation, there will be technical, safe installation, warranty and maintenance services attached to help customers feel secure when investing in installing high-value solar power systems.

Đơn vị tư vấn thi công lắp đặt điện mặt trời

Tip: consider the above content items and refer to contractor information to choose the right solution. With a system that is not only solar panels, inverters but a system that needs optimal balance (BOS) will be appreciated. Vu Son Solar wishes to bring value in line with customer's criteria.

10. Công nghệ “đám mây" trong hệ thống giám sát điện năng lượng mặt trời.

Energy efficiency as a core component of Industry 4.0. It has at its core energy efficiency. A good monitoring system platform will monitor PV efficiency, report interactive power output in the form of graphs, visual charts. Immediate damage diagnosis and very early warning so that you or the system supplier have a timely treatment plan. Integrated comprehensive reporting and analysis tools on the system with automatic report scheduling option. Decentralize management easily and with high security. The system operates throughout the system life cycle.